path: root/nuttx/ReleaseNotes

NuttX-0.1.0
^^^^^^^^^^^

This is the initial.  This initial includes the complete NuttX RTOS
with support for the Linux user mode simulation and the TI TMS320C5471
(Arm7) processor.  Partial support for the 87C52 is included.

This release has been verified on both the Linux user-mode and C5471
platforms using the test program under examples/ostest.  Test results
for the C5471 can be found in arch/c5471/doc/test-results.txt.

This tarball contains a complete CVS snapshot from March 9,2007.

NuttX-0.1.1
^^^^^^^^^^^

This is the second release of NuttX.  This release includes the following.
See the ChangeLog for more detailed description of the changes.

(1) General OS bugfixes (see the ChangeLog for details),
(2) bugfixes for the TI TMS320C5471 (Arm7) platform (see
    the ChangeLog)
(3) Complete support for the 87C52. (However, the 87C52
    release is not stable enough for general usage).
(4) Added the beginning of a shell call NuttShell (nsh)

This release has been verified on the Linux user-mode platform, the
Spectrum Digital TMS320C5471 EVM, and the PJRC 87C52 development board
using the test program under examples/ostest.

STATUS: The development status remains as ALPHA until further testing
is performed.

This tarball contains a complete CVS snapshot from March 14, 2007.

NuttX-0.1.2
^^^^^^^^^^^

This is the third release of NuttX.  This release is
primarily a bugfix release with minimal new features.  See
the ChangeLog for a more detailed description of the 
changes.

(1) Several important OS and ARM7 bugfixes,
(2) opendir(), closedir(), readdir(), etc. added
(3) Added C5471 watchdog timer.
(4) Created a shareable, serial driver.
(5) Added 'ls' command to NuttShell (nsh)
(6) Added a test of the round robin scheduler

This release has been verified on the Linux user-mode 
platform, the  Spectrum Digital TMS320C5471 EVM using the
test program under examples/ostest.

This tarball contains a CVS snapshot from March 19, 2007.

NuttX-0.2.1
^^^^^^^^^^^

This is the fourth release of NuttX.  This release adds adds
support for a new platform, restructures many header files,
and adds a few new features:

(1) Support for Neuros OSD / DM320
(2) Restructuring of header files for better POSIX compliance
(3) Added kill()
(4) Added POSIX timers
(5) bugfixes and documentation updates

This release has been verified on the Linux user-mode 
platform, the  Spectrum Digital TMS320C5471 EVM, and the 
Neuros OSD  using the test program under examples/ostest.  Because
of the stability of these tests, the project status
has been upgraded to 'beta.'

This tarball contains a complete CVS snapshot from March 22, 2007.

NuttX-0.2.2
^^^^^^^^^^^^

This is the fifth release of NuttX.  There is no major new
functionality in this release.  This release adds support
for new pthread barrier APIs, changes the directory
structure, to better handle different board configurations
using the same processor architecture, and corrects a few
defects.

See the ChangeLog for a complete list of changes.

This release has been verified on the Linux user-mode
platform and the Neuros OSD using the test program under
examples/ostest.  There are no known, critical defects but
the project development status remains at 'beta' status
pending further test and evaluation.

This tarball contains a complete CVS snapshot from
March 26, 2007.

NuttX-0.2.3
^^^^^^^^^^^^

This is the sixth release of NuttX.  This release is
primarily a bugfix release.  Numerous problems were fixed
as detailed in the change log.  New functionality includes
support for timed message queues.

See the ChangeLog for a complete list of changes.

This release has been verified on the Linux user-mode 
platform and the Neuros OSD using the test program under
examples/ostest. The results of the testing is available in
the source tree under configs/ntosd-dm320/doc/test-results.
There are no known, critical defects but the project
development status remains at 'beta' status pending further
test and evaluation.

This tarball contains a complete CVS snapshot from March 29,
2007.

NuttX-0.2.4
^^^^^^^^^^^^

This is the 7th release of NuttX.  This release is only to roll out
build changes to better support different SoC's that use the same
processor architecture.  In particular, the two existing ARM architectures,
c5471 and DM320 were combined into a single ARM directory.  This was done
in preparation for an LPC2148 port that is currently in progress.  There
is NO new functionality or significant bugfixes in this release.

See the ChangeLog for a complete list of changes.

This release has been verified on the Linux user-mode platform
and the Neuros OSD using the test program under examples/ostest.
The results of the testing is available in the source tree under
configs/ntosd-dm320/doc/test-results and under configs/sim/doc/test-results.
There are no known, critical defects but the project development status
remains at 'beta' status pending further test and evaluation.

This tarball contains a complete CVS snapshot from April 28, 2007.

NuttX-0.2.5
^^^^^^^^^^^^

This is the 8th release of NuttX.  This release includes:

(1) Several bug fixes
(2) Initial support for FAT filesystems.  Testing has not
    been exhaustive and some functionality is missing
   (mkdir, stat, unlink chmod, and rename functionality is 
    not yet implemented).
(3) Support for the NXP lpc2148 processor is included but
    is untested as of this writing.  The current 
    implementation includes only support for serial console
    and timer interrupt.

See the ChangeLog for a complete list of changes.

This release has been verified only on the Linux user-mode
platform.

This tarball contains a complete CVS snapshot from May 19,
2007.

NuttX-0.2.6
^^^^^^^^^^^

This is the 9th release of NuttX.  This is primarily a
bugfix release to correct a number of problems introduced
with the 0.2.5 release. This release does include some FAT
filesystem extensions including unlink(), mkdir(), rmdir(),
rename(), opendir(), closedir(), readdir(), seekdir(),
telldir(), rewindir().  There are some pending FAT changes
that did not make it into this release including stat(),
truncate(), and long file names.

See the ChangeLog for a complete list of changes.

This release has been verified only on the Linux user-mode platform.

This tarball contains a complete CVS snapshot from May 26, 2007.

NuttX-0.2.7
^^^^^^^^^^^

This is the 10th release of NuttX.  This is primarily a bugfix
release to correct a number of problems reported to me (thanks
Didier!). This release does include the final changes complete the
FAT filesystem logic including stat(), statfs(), and non-standard
APIs to manage FAT attributes.  At present, FAT long file names and
file truncate() are still not supported.

See the ChangeLog for a complete list of changes.

This release has been verified only on the Linux user-mode platform.

This tarball contains a complete CVS snapshot from June 9, 2007.

NuttX-0.2.8
^^^^^^^^^^^

This is the 11th release of NuttX.  This release:
(1) corrects important bugs in opendir() and realloc()
(2) adds support for environment variables
(3) adds several new C library interfaces
(4) extends several example programs

See the ChangeLog for a complete list of changes.

This release has been verified only on the Linux user-mode platform.

This tarball contains a complete CVS snapshot from July 2, 2007.

NuttX-0.3.0
^^^^^^^^^^^

This is the 12th release of NuttX.  This release includes the initial
integration of a network subsystem and the uIP TCP/IP stack into NuttX
(see http://www.sics.se/~adam/uip/index.php/Main_Page).  Also included
is a device driver for the Davicom DM90x0 Ethernet controller.

This integration is very preliminary.  Only a small portion of the
network functionality has been integrated and there are a number of
open issues (see the TODO file).  The network subsystem is pre-alpha
at this point in time.  I expect that it will stabilize and mature
over the next few releases.

The baseline functionality of NuttX continues to mature and remains at
post-beta (as long as the network is not used).

See the ChangeLog for a complete list of changes.

This release has been verified only on the Neuros OSD (DM320 ARM9)
platform using the DM90x0 driver.

This tarball contains a complete CVS snapshot from November 6, 2007.

NuttX-0.3.1
^^^^^^^^^^^

This is the 13th release of NuttX and the second release containing
the integration of a network subsystem and the uIP TCP/IP, UDP, and
ICMP stacks into NuttX (see http://www.sics.se/~adam/uip/index.php/Main_Page).

Many network-related problems have been fixed and the implementation
has matured significantly.  However, the level of network reliability
is probably still at the pre-alpha or early level.  It is sufficiently
complete that you may begin to perform some network integration and
is expected to achieve beta level of reliability over the next few
releases.

The baseline functionality of NuttX continues to mature and remains at
post-beta (as long as the network is not used).

See the ChangeLog for a complete list of changes.

This release has been verified only on the Neuros OSD (DM320 ARM9)
platform using the DM90x0 driver.

This tarball contains a complete CVS snapshot from November 19, 2007.

NuttX-0.3.2
^^^^^^^^^^^

This is the 14th release of NuttX and the 3rd release containing
the integration of a network subsystem and the uIP TCP/IP, UDP, and
ICMP stacks into NuttX (see http://www.sics.se/~adam/uip/index.php/Main_Page).

Many network-related problems have been fixed and the implementation
has matured significantly.  This release consists of:

o TCP-related bug-fixes
o TCP performance improvements
o Initial UDP integration
o Initial uIP micro webserver integration

See the ChangeLog for a complete list of changes.

The level of network reliability is at alpha level is expected to
achieve beta level of reliability over the next few releases.

The baseline functionality of NuttX continues to mature and remains at
post-beta.

This release has been verified only on the Neuros OSD (DM320 ARM9)
platform using the DM90x0 driver.

This tarball contains a complete CVS snapshot from November 23, 2007.

NuttX-0.3.3
^^^^^^^^^^^

This is the 15th release of NuttX and the 4th release containing
the integration of a network subsystem and the uIP TCP/IP, UDP, and
ICMP stacks into NuttX (see http://www.sics.se/~adam/uip/index.php/Main_Page).

Many network-related problems have been fixed and the implementation
has matured significantly.  This release consists of:

o TCP-related bug-fixes for disconnecting sockets
o Correction of some TCP read-ahead logic
o TCP performance improvements
o Misc. additions and cleanup (See the ChangeLog for a complete list of
  changes).

The level of network reliability is at an early beta release level.  The
baseline functionality of NuttX continues to mature and remains at
post-beta. Open network-related issues include only:

o Some minor unimplemented BSD socket functionality,
o Thread safety issues: the same socket cannot be used concurrently on
  different threads.
o Pending design changes necessary to support multiple network interfaces.
o IPv6 support is incomplete.

This release has been verified only on the Neuros OSD (DM320 ARM9)
platform using the DM90x0 driver. Any feedback for improving the network
reliability/performance would be greatly appreciated.

This tarball contains a complete CVS snapshot from November 28, 2007.

NuttX-0.3.4
^^^^^^^^^^^

This is the 16th release of NuttX and the 5th release containing
the integration of a network subsystem and the uIP TCP/IP, UDP, and
ICMP stacks into NuttX (see http://www.sics.se/~adam/uip/index.php/Main_Page).

This release is primarily a bug-fix release.  New features include
only:

o TELNET front-end to NSH,
o DHCPC server functionality, and
o C5471 Ethernet driver.

Numerous network related problems were fixed related to DHCPC, UDP
input processing, UDP broadcast, send timeouts, and bad compilation when
uIP is compiled at high levels of optimization.

The level of network reliability is at a strong beta release level.  The
baseline functionality of NuttX continues to mature and remains at
post-beta or production level.

Parts of this release were verified only on the Neuros OSD (DM320 ARM9)
platform using the DM90x0 Ethernet driver and other parts on the Spectrum
Digital C5471 EVM using the C5471 Ethernet driver. Any feedback about bugs
or suggestions for improving the network reliability/performance would be
greatly appreciated.

This tarball contains a complete CVS snapshot from December 10, 2007.

NuttX-0.3.5
^^^^^^^^^^^

This is the 17th release of NuttX this release is primarily a bug-fix
release and intended to synchronize with the current CVS contents.  See
the ChangeLog for a detailed list of changes and fixes.

This release were verified only on the Spectrum Digital C5471 EVM using
the C5471 Ethernet driver. Any feedback about bugs or suggestions for
improvement would be greatly appreciated.

This tarball contains a complete CVS snapshot from December 18, 2007.

NuttX-0.3.6
^^^^^^^^^^^

This is the 18th release of NuttX.  This release contains on a few
changes.  The primary purpose of this release is to synchronize with
the release of the pascal-0.1.0 add-on package.

This release of NuttX includes the following changes:

* Fixes for use with SDCC compiler
* Added a simulated z80 target (arch/z80)
* Fix deadlock errors when using stdio but with no buffering
* Add support for the add-on Pascal P-Code interpreter (pcode/)
  (see the pascal-0.1.0 package)

This release were verified only on the simulated Z80 and and host
simulation targets.  As usual, any feedback about bugs or suggestions
for improvement would be greatly appreciated.

This tarball contains a complete CVS snapshot from January 6, 2007.

====

There was an error in the initial 0.3.6 release that prevented
a successful build unless the Pascal add-on was present.  The
tarball was patched to include the fix.  Make sure that you download
the nuttx-0.3.6.1.tar.gz version to avoid this problem.

NuttX-0.3.7
^^^^^^^^^^^

This is the 19th release of NuttX.  This release includes the
preliminary port of NuttX to the ZiLOG z16f 16-bit microcontroller.
This port was verified using the ZiLOG z16f2800100zcog Development
and the ZiLOG ZDS-II toolchain. See http://www.zilog.com for
further information.

I emphasize that this is a preliminary release of the z16f port and
is only alpha or, perhaps, pre-alpha quality as of this writing.
There are a list of known issues in the TODO file in the root of
the NuttX directory.  The overall quality of NuttX (excluding the
z16f port) continues to improve beyond the late beta level.

The z16f port required numerous changes to NuttX to handle:

* NEAR and FAR addressing, and
* Use of a Windows native toolchain in a Cygwin build environment.

In addition to the z16f port, at least one very critical bug was
found and corrected in NuttX:  The thread-specific errno value of one
task was being randomly trashed when a different thread exited.

This release were verified on the ZiLOG z16f2800100zcog, Neuros OSD
(ARM9), and the simulation platforms.  As usual, any feedback about bugs
or suggestions for improvement would be greatly appreciated.

This tarball contains a complete CVS snapshot from January 31, 2008.

NuttX-0.3.8
^^^^^^^^^^^

This is the 20th release of NuttX.  This is a minor bugfix release.
It corrects a few minor problems, adds a few minor features, and
continues the integration of the ZiLOG Z18F and of the Pascal P-Code
add-on.  This release is synchronized with the release of Pascal-0.1.2.

This tarball contains a complete CVS snapshot from February 10, 2008.

NuttX-0.3.9
^^^^^^^^^^^

This is the 21st release of NuttX.  This is a minor future enhancement
release.  This release includes support for the ZiLOG Z8Encore! micro-
controller.  Also included is the initial framework for support for
the Z80, XTRS platform (http://www.tim-mann.org/xtrs.html).

This released has been verified only on the ZiLOG ZDS-II Z8Encore!
chip simulation.

This tarball contains a complete CVS snapshot from March 9, 2008.

NuttX-0.3.10
^^^^^^^^^^^^

This is the 22nd release of NuttX.  This is an important bug fix
release.  This release incorporates fixes to correct critical list
handling errors in task shutdown logic: One in timer deletion logic
(timer_delete.c) and one in stream logic (lib_init.c).  This release
also includes support to ZiLOG EZ80Acclaim microcontroller (EZ80F91
chip) and configurations for the ZiLOG z8f64200100kit (Z8F6423) and
ez80f0910200kitg (EZ80F091) development kit.

NuttX-0.3.11
^^^^^^^^^^^^

This is the 23rd release of NuttX.  This is another important bugfix
release.  This releases fixes several bugs:

* Two POSIX timer bugs: a memory leak as well a fatal sequencing error.
* Several FAT filesystem errors.
* A deadlock that can occur in opendir()

A few new features were also added:

* Support for recursive mutexes
* Added a RAM disk block driver
* The host simulator no longer uses direct Linux system calls and
  now also works on Cygwin.
* The OS test was strengthen and now runs as an endurance test

These changes were verified only on the Host simulator under Cygwin.
Please report any errors to me.

This tarball contains a complete CVS snapshot from June 1, 2008.

NuttX-0.3.12
^^^^^^^^^^^^

This is the 24th release of NuttX.  This release includes some minor
bugfixes as well as a few new features.  Bugs fixed include:

* Corrected an error in recursive mutex implementation.
* task_create() was only dup()ing the first three file descriptors.
* Fixed driver open reference counting errors in dup(), dup2(), and exit().
* Fixed error handling logic in fflush().

New features were also added:

* Pipes and pipe() API
* FIFOs and mkfifo() API
* mkfatfs() API can be used to format FAT file systems.

These changes were verified only on the Host simulator under Cygwin.
Please report any errors to me.

This tarball contains a complete CVS snapshot from August 10, 2008.

NuttX-0.3.13
^^^^^^^^^^^^

This is the 25th release of NuttX.  This release includes some
important bugfixes as well as a few new features.  Bugs fixed
include:

* Fixed problems with Cygwin-based console input.  NSH now works
  with the Cygwin simulator.
* sched_get_priority_max/min returned error on SCHED_RR
* Corrected detection of End-of-File in fgets()
* Fixed an error in opendir() that could cause an assertion to fail
  inappropriately.
* Corrected an error in the FAT that caused files opened for writing
  with O_APPEND to fail.
* Fix error in getopt() when called with argc==1
* Fix error in stat() when used on the root directory
* Fixed a critical bug that effects the way that environment variables
  are shared among pthreads.
* uIP port now supports multi-threaded, concurrent socket access.
  So, for example, one thread can be reading from a socket while
  another is writing to the socket.

New features were also added:

* New OS APIs: chdir() and getcwd()
* The Nuttx shell (NSH) has been extended in many ways.
  - New commands: mkfatfs, mkfifo, sleep, usleep, nice, sh, cd, and pwd
  - New memory inspection commands and heap usage commands
  - New capabilities:
    - Execution of commands in background
    - Execution of simple scripts
    - Redirection of command output
    - Last command status ($?)
  - Now supports if-then[-else]-fi construct
  - Other features as noted in the ChangeLog.

These changes were verified only on the Host simulator under Cygwin
and under Linux and also on the Neuros OSD (ARM9).  Please report
any errors to me.

This tarball contains a complete CVS snapshot from September 1, 2008.

nutt-0.3.14
^^^^^^^^^^^

This is the 26th release of NuttX.  This release includes some
important bugfixes as well as a few new features.  Critical bugs
fixed include:

FAT FS:
  * Fixed several critical bugs with regard to fat reading and
    writing and FAT12 accesses.  Basically the FAT FS only worked
    with my tiny test files and test cases.  A lot of stronger FAT
    tested is still needed!
  * Fixed another FAT bug in implementation of FAT lseek();
    this prohibited correct random access to large files.

Network:
  * Corrected a critical bug that may prevent recvfrom from receiving
    packets from most remote UDP port numbers.
  * Corrected an error in multi-threaded socket handling in send() and
    sendto().  Outgoing data could overwrite incoming data.
  * Corrected IP checksum calculation in ICMP and UDP message send logic.
  * Corrected an error in send() timeout logic.

New features were also added:

Network:
  * Added support for application access to ICMP protocol stacks
  * Added ping request logic (net/uip).
  * Added basic TFTP client logic (netutils/tftpc).

NuttShell (NSH):
  * New commands: 'test', '[', 'ping', 'mkrd', 'xd', and TFTP 'get' and 'put'
    See the new NuttShell User Guide for additional information.

Other less critical bugs were also fixed and other less important
features were were added.  See the ChangeLog for details.

These changes were verified only on the Neuros OSD (ARM9).  Please
report any errors to me.

This tarball contains a complete CVS snapshot from September 8, 2008.

nutt-0.3.15
^^^^^^^^^^^

This is the 27th release of NuttX.  This release includes some new features:

* Adds support for the ROMFS filesystem
* ROMFS supports mmap() to provide eXecute In Place (XIP) capability
* NuttShell (NSH) can be configured to use ROMFS to provide a tiny read-only
  filesystem with a startup script in /etc.
* Completed the basic port of the NXP LPC2148 on the mcu123.com board.
  The basic port includes successful booting, timer interrupts,
  serial console, successfully passing the examples/ostest, and a
  NuttShell (NSH) configuration.

These changes were verified only on the mcu123.com NXP LPC2148
board.  Please report any errors to me.

This tarball contains a complete CVS snapshot from September 20, 2008.

nutt-0.3.16
^^^^^^^^^^^

This is the 28th release of NuttX.  This release includes the first
support for USB in NuttX.  A set of USB APIs were added to support
USB device controller drivers and bindings to USB device class
drivers.  The form of the interface was inspired by the Linux Gadget APIs.

At present USB device controller drivers are included for:
  * The NXP LPC214x.  This driver has been verified and is an early alpha
    stage in quality.
  * TI DM320.  Coding for this driver is complete but it is completely
    untested as of this release.

A controller-independent class driver is also included for:
  * USB serial class device driver (emulates the Prolific PL2303
    serial-to-USB adapter).  This driver has only been verified with
    the Linux host PL2303 driver.

Other new features include:
  * Add an option to set aside a separate stack for interrupt
    handling (ARM only).  This is useful when memory is constrained,
    there are multiple tasks, and the interrupt stack requirement
    is high (as when USB is enabled).

A few bugs were also fixed:
  * Fixed the frequency of system timer interrupts in the NXP LPC214x port
    (off by 20x in nuttx-0.3.15)
  * Fixed serial driver bugs related to (1) open counts and (2) recognizing
    O_NONBLOCK on read.
  * Fixed an error in read(); it was not setting the errno on errors returned
    from the driver.

These changes were verified only on the mcu123.com NXP LPC2148 board
using with a Linux host.  Please report any errors to me.

This tarball contains a complete CVS snapshot from October 10, 2008.

UPDATE
^^^^^^
This release does not build for the ARM target when USB is disabled.
Here is the fix:

Index: arch/arm/src/common/up_internal.h
===================================================================
RCS file: /cvsroot/nuttx/nuttx/arch/arm/src/common/up_internal.h,v
retrieving revision 1.13
diff -u -r1.13 up_internal.h
--- arch/arm/src/common/up_internal.h   6 Oct 2008 16:20:52 -0000       1.13
+++ arch/arm/src/common/up_internal.h   13 Oct 2008 20:48:21 -0000
@@ -200,7 +200,8 @@
 extern void up_usbinitialize(void);
 extern void up_usbuninitialize(void);
 #else
-# define up_netinitialize()
+# define up_usbinitialize()
+# define up_usbuninitialize()
 #endif

 #endif /* __ASSEMBLY__ */

NuttX-0.3.17
^^^^^^^^^^^^

This is the 29th release of NuttX.  This release includes the
additional support for USB in NuttX.  The following new features
were added:

* Added support for SPI-based MMC/SD cards (with an SPI driver
  for the NXP LPC214x).
* Added USB storage class device side driver (BBB)
* Added an example that demonstrates the USB storage class by
  exporting the SPI based MMC/SD card on the NXP LPC214x.

This is an early alpha release of these drivers.  At present they
only work with debug features enabled so there are probably some
race conditions that occur only with debug features disabled.
(Anyone out there with a USB analyzer?  I would love to know what
is happening.)

Several important bugs were also fixed in the FAT file system, USB
serial driver and NXP LPC214x USB controller driver. (See the ChangeLog
for details.)

These changes were verified only on the mcu123.com NXP LPC2148 board
using a Linux development environment.  USB testing was performed
using both a Linux host and a WinXP host.  Please report any errors
to me.

This tarball contains a complete CVS snapshot from October 28, 2008.

NuttX-0.3.18
^^^^^^^^^^^^

This is the 30th release of NuttX.  This release includes two
partially completed ports, several new features, and a couple of
important bug fixes.  The two partially completed ports are:

  * The STMicro STR71x processor and configuration for the Olimex
    STR-P711 board.
  * The Hitachi SH-1 using the SH1_LCEVB1 (SH-1/US7032EVB1) board

Progress on these ports is stalled (as detailed in the ChangeLog).

The new features focus primarily on management of block devices and
extensions of the NuttShell (NSH).  These include:

  * A loop device that converts a file into a block device.
  * A block to character (BCH) driver that  allow access a block device as
    if it were character device.
  * Added strcasecmp() and strncasecmp() libc functions.
  * Added the 'dd' and 'losetup' commands to NSH. These commands
    (along with mkfatfs and mount), give good management of filesystems
    on the target.

Several bugs were fixed, the most important of which are:

  * Fixed a race condition workaround delay in LPC214X SPI logic.
    This was also the cause of some bad MMC/SD performance on that
    platform.

  * Fixed a recently introduced FAT file system problem: It would
    mount a (invalid) FAT file system even if the medium is not formatted!

  * Corrected two other important errors in the FAT lseek() implementation:
    1 - The sectors-per-cluster value was being reset to "1".
    2 - Important lseek logic was omitted when the seek position was zero.

The FAT filesystem has had many bugs fixed in it and, I think, is
now maturing and becoming stable.

These changes were verified only on the mcu123.com NXP LPC2148
board, the Hitachi SH1_LCEVB1 board, and the Linux simulator, all
using a Linux development environment.  Please report any errors
to me.

This tarball contains a complete CVS snapshot from November 16, 2008.

NuttX-0.3.19
^^^^^^^^^^^^

This is the 31st release of NuttX.  This release includes the
following new feature:

  * Add poll() and select() APIs that may be used to monitor for
    data availability on character devices or TCP/IP sockets.
  * Implemented support TCP/IP connection backlog.  This allows
    select() to wake-up on new connections to a listener socket.
  * Added definition of a framebuffer driver and implement framebuffer
    drivers for the simulated platform and the TI DM320 (untested
    as of the initial check-in).
  * Partially developed a graphics framework based on the framebuffer
    drivers, however, this will not be ready for use for a few more
    releases.  Currently this includes only a few color conversion
    routines and some rasterizing functions.  A tiny windowing system
    is under development but not ready for check-in yet.
  * Added support for fixed precision math.
  * Added support for outgoing multicast packets.

Several bugs were fixed, the most important of which are:

  * Fixed an important bug in the TCP/IP buffering logic.  When
    TCP/IP read-ahead is enabled and not recv() is in-place when a
    TCP/IP packet is received, the packet is placed into a read-ahead
    buffer.  However, the old contents of the read-ahead buffer
    were not being cleared and old data would contaminate the newly
    received buffer.

  * Changed the behavior of the serial driver read.  It now returns
    data as it is available rather than waiting for the full requested
    read size.  This makes functions like fgetc() work much more
    smoothly.

These changes were verified only on the Neuros OSD (ARM9) using a
Linux development environment. Please report any errors to me.

This tarball contains a complete CVS snapshot from November 26, 2008.

NuttX-0.4.0
^^^^^^^^^^^

This is the 32nd release of NuttX.  This release adds graphics
support and a tiny windowing subsystem.  That new graphics subsystem
is documented at http://nuttx.sourceforge.net/NXGraphicsSubsystem.html.
No other substantial changes were made.

These changes were verified only on the NuttX simulation platform
with X11 windows simulating a device framebuffer. Please report any
errors to me.

The version number was bumped up to 0.4.0 in part to reflect the
new graphics subsystem, but also to recognize the NuttX is approaching
complete functionality.  In the 0.3.x versions, network support was
added, Pascal P-code runtime support was added, FAT and ROMFS
filesystems were added, MMC/SD and USB device support were added.
There were also numerous extensions to the NuttShell, NuttX APIs,
and architecture ports.

This tarball contains a complete CVS snapshot from December 6, 2008.

NuttX-0.4.1
^^^^^^^^^^^

This is the 33rd release of NuttX.  This is a minor bugfix release.
The primary reason for this release is to correct numerous build
errors that have accumulated for the ZiLOG ZDS-II based targets.
All ZDS-II targets now build correctly (but have not been re-tested).
In addition to platform-specific build failures, this release also
adds the following features which were not tested as of the time
of the release:

  * Board support for the ZiLog ez80Acclaim! ez80f910200zco Development Kit
  * ZiLOG eZ80F91 EMAC driver

These changes were verified only on the NuttX simulation platform.
Please report any errors to me.

This tarball contains a complete CVS snapshot from February 6, 2009.

NuttX-0.4.2
^^^^^^^^^^^

This is the 34th release of NuttX.  This release adds no new OS
features but does include support for two new architectures:

  * ez80Acclaim!  Basic support has been integrated and verified
    for the ez80f910200zcog-d board (eZ80F91-based).  That basic
    support includes timer interrupts and serial console.  Ongoing
    work includes an EMAC driver that should be integrated for the
    next release nuttx-0.4.2.  eZ80Acclaim! support has been in the
    code base for some time, but has only just been integrated due
    to toolchain issues.

  * Renesas M16C/20.  Support for the Renesas SKP16C20 board has
    been included in the NuttX source tree.  However, as the
    eZ80Acclaim!, testing and integration of that port is stalled
    due to toolchain issues.

These changes were verified only on the ZiLOG eZ80910200zcog-d
board. Please report any errors to me.

This tarball contains a complete CVS snapshot from February 28, 2009.

NuttX-0.4.3
^^^^^^^^^^^

This is the 35th release of NuttX.  This release one important new
OS feature and corrects and extends the eZ80 port:

  * Priority Inheritance.  The basic NuttX waiting logic was extended
    to support priority inheritance. See the NuttX User Manual for
    further information:
    http://www.nuttx.org/NuttxUserGuide.html#priorityinheritance.

  * ez80Acclaim! Corrected several critical, show-stopping bugs on that
    platform including:
    - Errors in the serial driver interrupts.
    - An error in the eZ80 table.
  * eZ80Acclaim!: Completed integration of the eZ80F91 EMAC driver.

These changes were verified only on the ZiLOG eZ80910200zcog-d board
and on Cygwin-based simulation platform in various configurations.
Please report any errors to me.

This tarball contains a complete CVS snapshot from March 13, 2009.

NuttX-0.4.4
^^^^^^^^^^^

This is the 36th release of NuttX.  This release focuses on bugfixes
and extending and verifying certain networking features.

  * Important bugs were fixed in NSH, UDP checksum calculation, UDP
    bind() behavior for port==0, the eZ80Acclaim! EMAC driver, Z80
    interrupt handling, and in the C libraries.

  * Testing was extended to further verify the tiny webserver,
    DHCPD, wget(), and sendmail.

See the Changelog for a detailed description of these changes.

These changes were verified only on the ZiLOG eZ80910200zcog-d board
using the ZDS-II toolchain in Cygwin-based environment. Please
report any errors to me.

This tarball contains a complete CVS snapshot from March 29, 2009.

NuttX-0.4.5
^^^^^^^^^^^

This is the 37th release of NuttX.  This release focuses on a few new features.

  * The basic port for the Freescale ARM920T i.MX1 processor on the
    Freescale MX1ADS board.  Coding is complete for this port, but
    it is has not yet fully integrated
  * Extended I2C and SPI interface definitions
  * Add basic support for C++ applications.  Very simple C++
    applications can now be built against NuttX without any external
    libraries.  At present, only the most primitive C++ programs
    are supported, but it is hoped that this support will be extended
    in future releases.

See the Changelog for a detailed description of these changes.

This tarball contains a complete CVS snapshot from April 19, 2009.

NuttX-0.4.6
^^^^^^^^^^^

This is the 38th release of NuttX.  The release features support
for the Micromint Eagle-100 development board.  This board is based
around, the Luminary LM3S6918 MCU.  This is the first ARM Cortex-M3
architecture supported by Nuttx. This initial, basic port includes
timer and serial console with configurations to execute the NuttX
OS test and to run the NuttShell (NSH). Work is still underway on
this port and current plans are to have I2C, SSI, MMC/SD, and and
Ethernet driver in the 0.4.7 release.

Additional work was done on the MXADS i.MX1 port, however, that
work has been set aside until I complete work on the Eagle-100 (I
also need to come up with a 3V power supply).

Other changes in this release include: Extensions to the SPI interface
definition in order to handle 9-bit interfaces to displays.  Several
bugs were fixed (see the ChangeLog for a complete list of changes).

This tarball contains a complete CVS snapshot from May 19, 2009.

NuttX-0.4.7
^^^^^^^^^^^

This is the 39th release of NuttX.  This release focuses on cleaning
up and extending the Eagle100/LM3S6918 port released in nuttx-0.4.6
and on improved MMC/SD support.  New features include:

  * Improved reliably and additional drivers for the Eagle-100 board
    (LM3S6918 ARM Cortex-M3).  Additional drivers include Ethernet,
    SSI, and support for the on-board LEDs and microSD cards.

  * The SPI-based MMC/SD driver was extended to support SDHC Version
    2.xx cards.

In addition, this release includes several important bugfixes for
the LM3S6918, the LPC2148, the SPI-based MMC/SD driver, and to
FAT32.  See the ChangeLog for details of these bugfixes.

This tarball contains a complete CVS snapshot from May 29, 2009.

NuttX-0.4.8
^^^^^^^^^^^

This is the 40th release of NuttX.  This release adds:

  * Support for the Olimex STRP711 board.  That board is based on
    the STMicro STR711 MCU (ARM7TDMI). Integration is complete on
    the basic port (boot logic, system time, serial console). Two
    configurations have been verified: (1) The board boots and
    passes the OS test with console output visible on UART0, and
    the NuttShell (NSH) is fully functional with interrupt driven
    serial console.  An SPI driver is available but untested (because
    the Olimex card slot appears to accept only MMC cards; I have
    only SD cards).  Additional needed: USB and driver, MMC
    integration.

  * Support for the CodeSourcery and devkitARM Windows-native GNU
    toolchains.  Makefiles have been modified for the LM3S6918,
    LPC2148, and STR711 to support these toolchains under Cygwin.

This tarball contains a complete CVS snapshot from June 13, 2009.

NuttX-0.4.9
^^^^^^^^^^^

This is the 41st release of NuttX.  This release adds:

  * Support for a new binary format call NXFLAT that can be used to 
    execute separately linked programs in place in a file system.
    See http://www.nuttx.org/NuttXNxFlat.html.

  * Several important bugs were files related to networking and ROMFS.
    See the ChangeLog for a complete list.

This tarball contains a complete CVS snapshot from June 26, 2009.

NuttX-0.4.10
^^^^^^^^^^^

This is the 42nd release of NuttX.  This released focused on the
port of Jeff Poskanzer's THTTPD HTTP server (see
http://acme.com/software/thttpd/).  As of the 0.4.10 release, that
port is still not fully complete and functional.  However, numerous
related bug-fixes and functional additions for THTTPD were added:

  * Several new standard C-library functions (fileno, strstr,
    strpbrk, fcntl).
  * Improved and extended timing APIs (mktime, gmtime, gmtime_r,
    gettimeofday, localtime, localtime_r, and strftime)
  * Networking enhancements: recvfrom() and accept() now work with
    non-blocking sockets.
  * NXFLAT extensions (exec)
  * Pattern matching logic.
  * And miscellaneous bug fixes (see the ChangeLog for details).

This tarball contains a complete CVS snapshot from August 8, 2009.

NuttX-0.4.11
^^^^^^^^^^^^

This is the 43rd release of NuttX. This release of NuttX incorporates
the verified port of Jeff Poskanzer's THTTPD HTTP server (see
http://acme.com/software/thttpd/).  Many of the key features of
THTTPD have been tested on the Micromint Eagle-100 development board
(Cortex-M3).  These tests verify:

  * Serving of files from any file system
  * Execution of CGI executable.  This release supports execution
    of NXFLAT executables on a ROMFS file system
    (http://www.nuttx.org/NuttXNxFlat.html)

A standard CGI interface is used:  Information is pasted to the CGI
program via POST commands and via environment variables.  CGI socket
I/O is redirected to stdin and stdout so that the CGI program only
need to printf() to send its content back to the HTTP client.

Another value to this THTTPD integration effort has been that THTTPD
has provided a very good test bed for finding NuttX networking bugs.
Several very critical networking bugs have been fixed with this
0.4.11 release (see the ChangeLog for details).  Networking throughput
has also been greatly improved.  Anyone using NuttX networking
should consider upgrading to this release.

This tarball contains a complete CVS snapshot from September 16, 2009

NuttX-0.4.12
^^^^^^^^^^^^

This is the 44th release of NuttX.  This release adds basic support
for the STMicro STM32, Cortex-M3 MCU.  The specific port is to the
STMicro STM3210E-EVAL development board based around the STM32F103ZET6
MCU.  Some highlights of this port:

  * This basic port includes boot-up logic, interrupt driven serial
    console, and system timer interrupts.
  * Includes a basic STMicro RIDE7 project that can be used to
    perform basic STM32 board bring-up (due to RIDE7 size limitations,
    it cannot be used for the full NuttX bring-up).
  * Working, Tested Configurations: the NuttX OS test and the
    NuttShell (NSH) example.

This basic STM32 port will be extended in the 0.4.13 NuttX release.
Functionality needed for complete STM32 support includes:  USB
device driver, LCD driver and NX bringup on the development board's
display and MicroSD support.  An SPI driver and a DMA support was
included in this 0.4.12 release, but is not yet tested.

This tarball contains a complete CVS snapshot from October 17, 2009

NuttX-0.4.13
^^^^^^^^^^^^

This is the 45th release of NuttX.  The release extends the support
for the STMicro STM32 microcontroller.  Minimal support for the
STM3210E-EVAL development board based around the STM32F103ZET6 MCU
was released in NuttX-0.4.12.  This release adds:

  * A simple interface definition to support some FLASH, EEPROM,
    NVRAM, etc. devices.
  * Verified SPI operation using driver for SPI based FLASH parts
    M25P64 and M25P128.
  * Improved Cortex-M3 context switching.  This should improve
    context switching performance be 2x in certain cases.
  * Added a USB device-side driver for the STM32.  This is an early
    release of a very complex driver; some bugs are expected.
  * The USB driver has been verified against the USB serial device
    class driver.  There is at least one known outstanding issue
    (see the full bug description in the TODO list).

This release also corrects some important bugs in the early STM32 release:

  * Fixed several errors the prevented operation of NuttX on an
    STM32 development board using USART2 as the serial console.
  * Fixed and optimization-dependent race condition in the clock
    initialization.
  * Fixed a critical bug in the interrupt control logic that could
    cause interrupt operations to failed used for interrupts in a
    certain range.

This tarball contains a complete CVS snapshot from November 4, 2009

NuttX-4.14
^^^^^^^^^^

This is the 46th release of NuttX.  The release extends the support
for the STMicro STM32 microcontroller.  Minimal support for the
STM3210E-EVAL development board based around the STM32F103ZET6 MCU
was released in NuttX-0.4.12 and extended in Nuttx-0.4.13 to include
initial USB support.  This completes the STM32F103ZET6 and adds:

New Generic RTOS Features:

  * Added generic support that can be included in any block driver
    to provide read-ahead buffering and write buffering for improved
    driver performance.
  * Added a generic worker thread that can used to defer processing
    from an interrupt to a task.
  * Defined a generic SD/SDIO interface can can be bound to a MMC/SD
    or SDIO driver to provide SDIO support.
  * Implemented a an SDIO-based MMC/SD driver using this new SDIO
    interface.

New STM32 Features:

  * Add support to configure an STM32 input GPIO to generate an
    EXTI interrupt.
  * Added support for buttons on the STM3210E-EVAL board.
  * Implemented an STM32 version of the common the SDIO interface.
  * Added a configuration to exercise the STM32 with the USB mass
    storage device class example.

This release also corrects some important bugs in the early STM32 release:

  * Correct error handling in the mount() logic.
  * Fixed several STM32 DMA-related issues. Integrated and debugged
    STM32 DMA functionality that was added in 0.4.12.
  * Fixed several bugs in the STM32 USB device-side driver.

NOTE:  This version, 4.14, is equivalent to what would have been
called 0.4.14 to follow 0.4.13.  The zero has been eliminated from
the front of the version number to avoid confusion about the state
of development:  Some have interpreted the leading zero to mean
that the code is in some way unstable.  That was not the intent.
Beginning in January 2010, I will switch to the 2010.nn versioning
as many others have done to avoid such confusion.

This tarball contains a complete CVS snapshot from December 2, 2009

NuttX-5.0
^^^^^^^^^

This is 47th release of NuttX and the successor to nuttx-4.14.  This
major revision number has been incremented to indicate that an
incompatibility with previous nuttx releases has been introduced.
This version adopts standard fixed width integer names as specified
by the ANSI C99 standard.  The core logic of NuttX is older than
that standard and did not conform to it.

If you have applications running on NuttX-4.14, those applications
should continue to build and execute without problem on NuttX-5.0.
However, if you have device drivers or other OS-internal logic, you
will probably have to make some minor changes to your code to use
this version.  Below is a summary of those changes:

  * If you include sys/types.h to get the non-standard, fixed width
    integer types (uint32, uint16, ubyte, etc.), that is no longer
    necessary.
  * Instead, you will need to include stdint.h where the new fixed
    width integer types are defined (uint32_t, uint16_t, uint8_t, etc).
  * You will have to change all occurrences of the following types:

    uint32 -> uint32_t
    uint16 -> uint16_t
    ubyte  -> uint8_t
    uint8  -> uint8_t
    sint32 -> int32_t
    sint16 -> int16_t
    sint8  -> int8_t

 * In addition, the non-standard type 'boolean' must replaced with
   the standard type 'bool'.  The type definition for 'bool' is in
   stdbool.h

This change in typing caused small changes to many, many files.  It
was verified that all configurations in the release still build
correctly (other than the SDCC-based configurations).  Regression
testing was performed on a few configurations, but it is possible
that minor build issues still exist. (If you encounter any, please
let me know and I will help you to fix them.)

In the course of the regression testing, several important bugs
unrelated to the type changes were found and corrected.

  * Fixed an important error in the RX FIFO handling logic of the
    LM3S6918 Ethernet driver.
  * Corrected the handling of TCP sequence numbers in the TCP stack.
  * And other less important bugs as detailed in the ChangeLog.

The primary focus of this release was standards compatibility, but
a few new features were added including a (1) Flash Translation
Layer (FTL) that will support filesystems on a FLASH device and (2)
partial ports for the STM32F107VC and HCS12 C9S12NE64 MCUs.  Those
ports are very incomplete as of this writing.

This tarball contains a complete CVS snapshot from December 21, 2009

NuttX-5.1
^^^^^^^^^

This is the 48th release of NuttX.  This release adds support for
two new MCU architectures in various states of development:

* AT91SAM3U (http://www.atmel.com/products/at91/sam3landing.asp?family_id=605)

  This release adds support for the SAM3U-EK development board with
  the AT91SAM3U4E MCU
  (http://www.atmel.com/dyn/products/product_card_mcu.asp?part_id=4562).
  As with most NuttX architecture releases, the release will be
  rolled out in two parts:  A basic port and an extended port.

  NuttX-5.1 includes the basic port for the SAM3U-EK board.  This
  release passes the NuttX OS test and is proven to have a valid
  OS implementation.  It supports the basic boot-up, serial console
  and timer interrupts.  A configuration to support the NuttShell
  is also included.

  The extended port will also include support for SDIO-based SD
  cards and USB device (and possible LCD support).  These extensions
  may or may not happen by the Nuttx 5.2 release as my plate is
  kind of full now.

* LPC3131 (http://ics.nxp.com/products/lpc3000/lpc313x.lpc314x.lpc315x/)

  This release also adds the complete implementation of the basic
  port for the NXP LPC3131 MCU on the Embedded Artists EA3131 board
  (http://www.embeddedartists.com/products/kits/lpc3131_kit.php).
  That port, unfortunately has stalled due to tools issues.  Those
  tool issues have been resolved and I am confident that the verified
  basic port will be available in NuttX-5.2.

  The extended release will follow and should include SDIO-based
  SD card support and device USB.

A few additional features and bugfixes of a minor nature were also
incorporated as detailed in the ChangeLog.

NuttX-5.2
^^^^^^^^^

This is the 49th release of NuttX.  This release completes the
verification of the basic port for the NXP LPC3131 MCU on the
Embedded Artists EA3131 board
(http://www.embeddedartists.com/products/kits/lpc3131_kit.php).
This basic port includes basic boot-up, serial console, and timer
interrupts.  This port has been verified on the using the NuttX OS
test and includes a working implementation of the NuttShell (NSH).

An extended release will follow and should include SDIO-based SD
card support and device USB.

NuttX-5.3
^^^^^^^^^

This is the 50th release of NuttX.  This release support for one new
architecture:

  * A basic port for the NXP LPC2378 MCU on the Olimex-LPC2378
    development board was contributed by Rommel Marcelo.

And extensions to two existing architectures:

  * David Hewson contributed a dual-speed (full/high) USB device-side
    driver for the NXP LPC3131 on the Embedded Artists EA3131
    development board.

  * A DMA driver and a high speed MCI driver for the Atmel AT91SAM3U
    are included (but not fully tested in this release).

Two important bugfix was also included:

  * An important fix to the USB mass storage driver was contributed
    by David Hewson.
  * A serious error in the AT91SAM3U PIO handling was fixed.

NuttX-5.4
^^^^^^^^^

This is the 51st release of NuttX.  This release includes one new,
important extension to th NX graphics system (See
http://www.nuttx.org/NXGraphicsSubsystem.html).

NX was develop a couple years back on hardware that supported only
framebuffer devices, that is, video hardware with video memory
directly converts the memory content to video.  However, most MCUs
that NuttX focuses on do not support such video memory; rather,
that typically only support LCDs via parallel or serial interfaces.

This release of NuttX extends NX so that now renders directly to
the LCD device via its serial or parallel interface.  No in-memory
copy of the screen memory need be maintained so this solution should
also work in MCUs with very limited SRAM.

This initial release of this feature includes the verified NX
extensions plus a driver for the HX8347, 16-bit parallel LCD.  This
LCD supports 16-bit RGB (5:6:5).

NuttX-5.5
^^^^^^^^^

This is the 52nd release of NuttX.  This release includes one new
port, some new drivers and some important bugfixes:

  * NuttX was ported to the Luminary/TI LM3S6965 Ethernet Evaluation
    Kit.  At present, that port includes an OS test configuration
    and a NuttShell (NSH) configuration with Telnet support.

    MMC/SD and Networking support are provided but not thoroughly
    verified in this release: Current development efforts are focused
    on porting the NuttX window system (NX) to work with the
    Evaluation Kits OLED display.

  * A NuttX Ethernet driver for the Microchip ENC28J60 SPI Ethernet
    chip is available in the source tree (but has not yet been fully
    verified because I haven't properly connected it to hardware
    yet).

  * The Olimex STR-P711 NuttX port was extended to support the
    ENC28J60 and some new networking configurations were added.
    The ENC28J60 has not been tested on the STR-P711, however,
    because of hardware issues (I don't think the USB powered board
    provides enough power for the ENC28J60 and I don't have the
    right wall wart yet).

    Along the way, external interrupt support (XTI) was added to
    the STMicro STR-P711 port and some important bugs were fixed
    in the STR-P711 SPI driver.

  * Added (optional) floating point support for printf().
    (Contributed by Yolande Cates.)

  * Corrected an important UDP reference counting error.  It was
    not a serious error, but it trigger an assertion was IS a serious
    error.

NuttX-5.6
^^^^^^^^^

This is the 53rd release of NuttX.  This release includes one several
new drivers for existing NuttX ports:

  * This port adds support for the RiT displays P14201 4-bpp,
    greyscale OLED.  4-bpp greyscale support was integrated into
    the NX graphics sub-system and verified using the TI/Luminary
    LP3S6965 Ethernet Evaluation Kit.

  * The M25Px driver was extended for the M24P1 FLASH part (see NOTE).

  * An I2C driver and (basic) SPI driver were added for the NXP
    LPC313x port.  The I2C interface definition was extended to
    efficiently handle multiple I2C transfers.
    (Contributed by David Hewson.)

As well as a few, important USB-related bugfixes (See the ChangeLog
for details).

This release also includes the beginnings of a port for the NXP
LPC1768 MCU.  However, it is too early for that port to be useful
(stay tuned for a future announce of the availability of the LPC1768
port).

NuttX-5.7
^^^^^^^^^

This is the 54th release of NuttX.  This release adds basic support
for one new ARM Cortex-M3 architecture:

  * Added support for NXP LPC1768 MCU as provided on the Nucleus
    2G board from 2G Engineering (http://www.2g-eng.com).
  * Some initial files for the LPC17xx family were released in NuttX
    5.6, but the first functional release for the NXP LPC1768/Nucleus2G
    occurred with NuttX 5.7.
  * That initial basic release included timer interrupts and a
    serial console and was verified using the NuttX OS test.
  * That release includes a verified NuttShell (NSH) configuration
    (see the http://www.nuttx.org/NuttShell.html).
  * Also included are unverified SPI and USB device drivers.

Further efforts include:
  (1) development of a DMA support library
  (2) SPI-based MMC/SD support
  (3) verification of the USB driver

Watch for announcement of the completed LPC1768 port expected in
NuttX-5.8.

NuttX-5.8
^^^^^^^^^

This is the 55th release of NuttX.  This includes several important
bugfixes:

  * Corrects some interrupt vectoring for the TI/Stellarix LM3S
    port
  * Correct initialization logic for NXP LPC17xxx NuttX ports:
    Power was not being provided to the GPIO module!
  * Corrected (but did not verify) implementation of the optional
    interrupt stack feature (all Cortex M3 architectures).
  * Correct a HardFault in the LPC17xx SSP driver.

Additional minor fixes are also included as detailed in the ChangeLog.

Several new features have been fully developed and included in this
release, but full verification of most of these new features has
been blocked for a variety of issues:

  * Added microSD support for the NuttShell (NSH) configuration in
    the Nucleus2G LPC1768 port.  For reasons that have not yet been
    determined, I have not successfully accessed the microSD card
    as of this writing.
  * Two USB configurations were also added for the Nucleus2G board:
    One to support the USB serial device and one for the USB mass
    storage device.  Some testing of the USB driver was performed,
    but full verification is stalled for an OTG style USB cable.
  * LEDs now work correctly on the Nucleus2G LPC1768 board.
  * The NuttX/uIP networking subsystem now supports IGMPv2 client.
    IGMP (Internet Group Multicast Protocol) network "appliances"
    to join into multicast groups.  Outbound traffic to enter and
    leave multicast groups has been verified, but full verification
    will require a switch capable of multicast.  Issues associated
    with the receipt of multicast packets are likely.

NuttX-5.9
^^^^^^^^^

This is the 56th release of NuttX.  This release is difficult to
categorize; NuttX-5.9 was really released because there were too
many changes accumulating in CVS -- a few important, some unfinished
implementations, and a couple of important bugfixes.

  * By far biggest change in this release is the complete implementation
    of on-demand paging support.  This feature will allow you to
    execute large programs on a mass storage device (such as SPI
    FLASH) in a small RAM.  All of the core on-demand paging logic
    was completed (see http://www.nuttx.org/NuttXDemandPaging.html)
    and support was implemented for the ARM-9 family.  A test
    configuration is in place for the NXP LPC3131.  It has been
    verified that this new logic does not interfere with normal
    fixed-page ARM9 operation, but otherwise this new on-demand
    paging feature is untested.
  * Add support for the CodeSourcery toolchain to the Olimex-lpc2378
    port and for the Neuros OSD port.
  * The Neuros OSD port has been updated to work with the production
    v1.0 OSD (previously it only worked with the development board).
  * And some miscellaneous feature enhancements as detailed in the
    ChangeLog.

This includes several important bugfixes:

  * NXP LPC17xx - Fixed a critical bug in the GPIO configuration
    logic: When attempting to set no pull-up or pull-down (floating),
    it would, instead, select pull-down.

  * TI/Luminary LM3Sxxxx - Fixed:
    (1) A logic error in an address table lookup.
    (2) GPIO port encoding the limited support to only 8 GPIO ports.

  * Corrected the lease time in the DHCPC implementation:  It was
    not in host byte order.

  * And several other less important bugs as documented in the
    ChangeLog: Warnings, cornercase compilation problems, etc.

NuttX-5.10
^^^^^^^^^^

This is the 57th release of NuttX.  This release includes a combination
of some new features as well as several bugfixes.  New features
include:

  * TI/Luminary Stellaris LM3S9B96:
    Header file changes contributed by Tiago Maluta.
  * TI/Luminary Stellaris LM3S8962:
    Header file changes and support for the Stellaris LM3S8962
    Ethernet+CAN Evaluation Board contributed by Larry Arnold.
  * On-Demand Paging Support:
    The basic logic for the On-Demand Paging feature is complete,
    implemented for the NXP LPC3131, and partially tested.  See
    http://www.nuttx.org/NuttXDemandPaging.html.  Some additional
    test infrastructure will be needed in order to complete the
    verification.  See configs/ea3131/README.txt for details.
  * Two Pass Build Support:
    The make system now supports a two pass build where a relocatable,
    partially linked object is created on the first pass and that
    object is linked with the NuttX libraries to produce the final
    executable on the second pass.  This two pass build is currently
    only used to support the On-Demand paging feature:  The first
    pass link forces critical logic into the locked text region;
    the second pass builds the NuttX executable more-or-less as
    normal.
  * CONFIG_APP_DIR:
    Generalized the way in which applications are built and linked
    with NuttX.  The new configuration CONFIG_APP_DIR replaces
    CONFIG_EXAMPLE.  CONFIG_EXAMPLE used to identify the sub-directory
    within the NuttX examples/ directory that held the example
    application to be built.  That made it awkward to configure to
    build an application that resides outside of the NuttX examples/
    directory.  CONFIG_APP_DIR is more general; it can be used to
    refer to any directory containing the application to be built.

    For people who have their own configurations and/or Makefiles,
    you will need to make a couple of changes:

      - Replace all occurrences of CONFIG_EXAMPLE=foobar with
    CONFIG_APP_DIR=examples/foobar in all of the configuration
    files.
      - Replace any occurrences of examples/$(CONFIG_EXAMPLE) with
    $(CONFIG_APP_DIR)
      - Replace any occurrences of lib$(CONFIG_EXAMPLE)$(LIBEXT)
        with libapp$(LIBEXT) in your Makefiles.
      - Check any other occurrences of CONFIG_EXAMPLE.

  * Several bugfixes are included as well as code changes to eliminate
    some warnings.  See the ChangeLog for details.

NuttX-5.11
^^^^^^^^^^

This is the 58th release of NuttX.  This is a bugfix release.

  * One very important bug fixes a race condition that can occur
    using semaphores that can be awakened by signals.  Under this
    particular race condition, a task could hang waiting for a
    semaphore.
  * Corrections to lm3s8962 port contributed by Larry Arnold.  That
    port is purported to work correctly with these changes in place.

Plus less critical bugfixes as detailed in the ChangeLog.  New features
include:

  * A new configuration to support the mbed.org LPC1768 board.
    (Contributed by Dave Marples.)
  * A driver for the Atmel AT45DB161D 4Mbit SPI FLASH part

NuttX-5.12
^^^^^^^^^^

This is the 59th release of NuttX.  This is a critical bugfix release.

  * Fixed an important error in the signal trampoline logic.
    Essentially, interrupts are re-enabled while the signal handler
    executes, but the logic to re-disable the interrupts before
    returning from the signal handler trampoline was missing.  Under
    certain circumstances, this can cause stack corruption.  This
    was discovered by David Hewson on an ARM9 platform, but since
    the code has been leveraged, the bug has been propagated from
    ARM to Cortex-M3, AVR32, M16C, SH1, ZNEO, eZ80, Z8, and Z80 --
    almost every architecture. The correction has been incorporated
    for all architectures but only verified on a few.

Other notable changes in NuttX-5.12:

  * A complete port for the AVR32 (AT32UC3B0256) is incorporated
    in the source tree.  Testing of this port is underway now.  This
    release was made before verifying this port in order to get the
    important bugfix in place.

  * Other miscellaneous bugfix and enhancements as noted in the
    ChangeLog.

NuttX-5.13
^^^^^^^^^^

This is the 60th release of NuttX.  Headlines for this release
include:

  * AVR32, www.mcuzone.com AVR32DEV1

    The port for the www.mcuzone.com AVRDEV1 board based on the
    Atmel AT32UC3B0256 MCU was (almost) fully integrated. The port
    now successfully passes the NuttX OS test (examples/ostest).
    A NuttShell (NSH) configuration is in place (see the NSH User
    Guide at http://www.nuttx.org/NuttShell.html). Testing of that
    NSH configuration, however, has been postponed (because it got
    bumped by the Olimex LPC1766-STK port -- see below)

    Current Status: I think I have a hardware problem with my serial
    port setup. There is a good chance that the NSH port is complete
    and functional, but I am not yet able to demonstrate that. At
    present, I get nothing coming in the serial RXD line (probably
    because the pins are configured wrong or I have the MAX232
    connected wrong).

    A complete port will include drivers for additional AVR32 UC3
    devices -- like SPI and USB --- and will be available in a
    later release, time permitting.

  * LPC1766, Olimex LPC1766-STK

    Support for the Olimex-LPC1766 is newly added to NuttX and is
    still undergoing development, test, and integration. Verified
    configurations for the NuttX OS test and for the NuttShell (NSH,
    see the NSH User Guide at http://www.nuttx.org/NuttShell.html.
    Additional USB configurations are in the release as well, but
    they have not yet been verified.  Goals for NuttX-5.14 include:
    (1) An Ethernet driver, (2) Verified USB support, and (3) SD
    card support.

  * Additional changes and bugfixes as detailed in the ChangeLog.

NuttX-5.14
^^^^^^^^^^

The 61st release of NuttX, NuttX-5.14, was made on November 27,
2010.  This release includes multiple, important bugfixes as well
as a new driver for the NXP LPC1766.

Important bugfixes include:

  * Cortex-M3 Hard Fault.  Fixed a hard fault problem that can occur
    if certain types of interrupts are pending at the time another
    interrupt returns. This problem has only been observed on the
    LPC1766 (returning from a SYSTICK interrupt with a pending
    Ethernet interrupt).  However, it is assumed that all Cortex-M3
    ports could have this as a latent bug.

  * TCP/IP Sequence Number Bug.  Corrected errors some important
    logic in the way that sequence numbers are managed when send()
    sends out packets before a previous packet has been acknowledged.
    Some of that send() logic was incompatible with logic in the
    uIP layer.  Errors seen include: (1) The final final packet in
    a sequence of packets might be too large!  In the THTTPD example,
    this might leave some garbage at the bottom of the display. Or
    (2) send() might hang with outstanding, unacknowledged data
    (and with no re-transmission requests).  This was due to
    differences in sequence number handling in send() and in
    uip_tcpinput.c; uip_tcpinput.c thought (incorrectly) that all
    of the bytes were acknowledged; send.c knew that they were not.

  * One-Shot POSIX Timer Bug. Fixed an error in set-up of a one-shot
    POSIX timer.  It was using the repetitive timer value (which
    is zero in the one-shot case), always resulting in a 10Ms timer!
    Found and fixed by Wilton Tong.

Additional support has been included for the Olimex-LPC1766.  Support
for that board was added to NuttX 5.13.  This release extends that
support with an Ethernet driver.  Verified configurations are now
available for the NuttX OS test, for the NuttShell (NSH, see
http://www.nuttx.org/NuttShell.html), for the NuttX network test,
and for the THTTPD webserver. (Additional USB configurations are
in the release as well, but those have not yet been verified.  Goals
for NuttX-5.15 (and beyond) include: (1) Verified USB support, (2)
SD card support, and (3) LCD support.

NuttX-5.15
^^^^^^^^^^

The 62nd release of NuttX, NuttX-5.15, was made on December 12,
2010.  This release includes several bugfixes as well as feature
enhancements, primarily for the Olimex LPC1766-STK board.

Important bugfixes included:

  * Additional fixes needed with the TCP sequence number problem
    "fixed" in NuttX-5.14.
  * In the send() logic, now checks if the destination IP address
    is in the ARP table before sending the packet; an ARP request
    will go out instead.  This improves behavior, for example, on
    the first on the first GET request from a browser
  * All USB class drivers need to call DEV_CONNECT() when they are
    ready to be enumerated.  That is, (1) initially when bound to
    the USB driver, and (2) after a USB reset.
  * The SPI_SETBITS macro was calling the SPI setmode method.
  * And several other bug fixes of lower importance (see the
    ChangeLog for details).

And feature enhancements:

  * The LPC176x Ethernet driver was using all of AHB SRAM Bank0 for
    Ethernet packet buffers (16K).  An option was added to limit
    the amount of SRAM used for packet buffering and to re-use any
    extra Bank0 memory for heap.

  * Enabled networking and SD/MMC card support in the Olimex
    LPC1766-STK NuttShell (NSH) configuration.

  * The LPC176x USB driver is now fully fully functional.
  * Added an optional cmddata() method to the SPI interface.  Some
    devices require an additional out-of-band bit to specify if the
    next word sent to the device is a command or data. The cmddata
    method provides selection of command or data.

  * A driver for the Nokia 6100 LCD (with either the Phillips PCF8833
    LCD controller and for the Epson S1D15G10 LCD controller) and
    an NX graphics configuration for the Olimex LPC1766-STK have
    been added.  However, neither the LCD driver nor the NX
    configuration have been verified as of the this release.

NuttX-5.16
^^^^^^^^^^

The 63rd release of NuttX, Version 5.16, was made on January 10,
2010 and is available for download from the SourceForge website.
This release includes initial support for USB host in NuttX. The
USB host infrastructure is new to NuttX. This initial USB host release
is probably only beta quality; it is expected the some bugs remain
in the logic and that the functionality requires extension.

Below is a summary of the NuttX USB host implementation as extracted
from the NuttX Porting Guide:

  6.3.9 USB Host-Side Drivers
  * include/nuttx/usb/usbhost.h. All structures and APIs needed to
    work with USB host-side drivers are provided in this header
    file.
  * struct usbhost_driver_s. Each USB host controller driver must
    implement an instance of struct usbhost_driver_s. This structure
    is defined in include/nuttx/usb/usbhost.h.  Examples:
    arch/arm/src/lpc17xx/lpc17_usbhost.c.
  * struct usbhost_class_s. Each USB host class driver must implement
    an instance of struct usbhost_class_s. This structure is also
    defined in include/nuttx/usb/usbhost.h.  Examples:
    drivers/usbhost/usbhost_storage.c
  * USB Host Class Driver Registry. The NuttX USB host infrastructure
    includes a registry. During its initialization, each USB host
    class driver must call the interface, usbhost_registerclass()
    in order add its interface to the registry. Later, when a USB
    device is connected, the USB host controller will look up the
    USB host class driver that is needed to support the connected
    device in this registry.  Examples: drivers/usbhost/usbhost_registry.c,
    drivers/usbhost/usbhost_registerclass.c, and
    drivers/usbhost/usbhost_findclass.c,
  * Detection and Enumeration of Connected Devices. Each USB host
    device controller supports two methods that are used to detect
    and enumeration newly connected devices (and also detect
    disconnected devices):
    + int (*wait)(FAR struct usbhost_driver_s *drvr, bool connected);
      Wait for a device to be connected or disconnected.
    + int (*enumerate)(FAR struct usbhost_driver_s *drvr);
      Enumerate the connected device. As part of this enumeration
      process, the driver will (1) get the device's configuration
      descriptor, (2) extract the class ID info from the configuration
      descriptor, (3) call usbhost_findclass() to find the class
      that supports this device, (4) call the create() method on
      the struct usbhost_registry_s interface to get a class instance,
      and finally (5) call the connect() method of the struct
      usbhost_class_s interface. After that, the class is in charge
      of the sequence of operations.
  * Binding USB Host-Side Drivers. USB host-side controller drivers
    are not normally directly accessed by user code, but are usually
    bound to another, higher level USB host class driver. The class
    driver exports the standard NuttX device interface so that the
    connected USB device can be accessed just as with other, similar,
    on-board devices. For example, the USB host mass storage class
    driver (drivers/usbhost/usbhost_storage.c) will register a
    standard, NuttX block driver interface (like /dev/sda) that can
    be used to mount a file system just as with any other other
    block driver instance. In general, the binding sequence is:

    1. Each USB host class driver includes an initialization entry
       point that is called from the application at initialization
       time.  This driver calls usbhost_registerclass() during this
       initialization in order to makes itself available in the
       event the the device that it supports is connected.  Examples:
       The function usbhost_storageinit() in the file
       drivers/usbhost/usbhost_storage.c
    2. Each application must include a waiter thread thread that
       (1) calls the USB host controller driver's wait() to detect
       the connection of a device, and then (2) call the USB host
       controller driver's enumerate method to bind the registered
       USB host class driver to the USB host controller driver.
       Examples: The function nsh_waiter() in the file
       configs/nucleus2g/src/up_nsh.c and the function nsh_waiter()
       in the file configs/olimex-lpc1766stk/src/up_nsh.c.
    3. As part of its operation during the binding operation, the
       USB host class driver will register an instances of a standard
       NuttX driver under the /dev directory. To repeat the above
       example, the USB host mass storage class driver
       (drivers/usbhost/usbhost_storage.c) will register a standard,
       NuttX block driver interface (like /dev/sda) that can be
       used to mount a file system just as with any other other
       block driver instance.  Examples: See the call to
       register_blockdriver() in the function usbhost_initvolume()
       in the file drivers/usbhost/usbhost_storage.c.

NuttX-5.17
^^^^^^^^^^

The 64th release of NuttX, Version 5.17, was made on January 19,
2011 and is available for download from the SourceForge website.
This release follows close on the heels of the 5.16 release and
extends the USB host capabilities first introduced in that version.

  * The LPC17xx USB host controller driver was extended to (1) add
    support for low-speed devices, (2) handle multiple concurrent
    transfers on different endpoints (still only one TD per endpoint),
    and (3) handle periodic interrupt endpoint types.

  * Add a USB host HID keyboard class driver.  Now you can connect
    a standard USB keyboard to NuttX and receive keyboard input for
    an application.

And other changes as detailed in the ChangeLog.

NuttX-5.18
^^^^^^^^^^

The 65th release of NuttX, Version 5.18, was made on February 27,
2011 and is available for download from the SourceForge website.
This is first release from the new NuttX SVN repository.  This
release is made primarily to keep the release tarball in synchronization
with SVN.  Many smaller changes have been made as identified in the
ChangeLog.  Headlines include:

  * Incorporate several important uIP patches -- including the well
    known patch to handle missing SYNACK.
  * The Freescale mc8s12ne64 port is code complete but testing has
    not yet begun due to toolchain issues.  Added support for the
    Future Electronics Group NE64 Badge board.
  * Added support for a new STM32 board, the ISOTEL NetClamps VSN
    V1.2 ready2go sensor network platform.  This board is based on
    a STM32F103RET6 and includes some interesting power saving/clock
    control extensions.
  * USB host support expanded to handle vendor specific USB devices.
  * Incorporated the LUFA HID parser.
  * Various bugfix as detailed in the ChangeLog

NuttX-5.19
^^^^^^^^^^

The 66th release of NuttX, Version 5.19, was made on March 12, 2011
and is available for download from the SourceForge website.  This
release includes several new features in various states of integration
and maturity:

  * 486SX QEMU port.  This port supports the Intel 486SX architecture
    using the QEMU simulator.  Initial functionality is in place a
    partially tested.  There are still some outstanding issues with
    timer interrupts.
  * Platform specific application support.  A new apps/ directory
    appears in this port.  This apps/ directory provides a mechanism
    for applications using NuttX to have a highly customized
    initialization process. It supports a set of end-user applications
    than can be executed (1) standalone so you can have a fully
    customized application startup, or (2) on top of NSH.  Think
    of it this way:  In a buckled-up embedded application, your
    end-user programs will probably have their own dedicated start-up
    logic.  But, during development, you might want to have you
    applications available and executable from the NSH command line.
    This apps/ add-on (and NSH hooks) was contributed by Uros to
    accomplish just that.
  * NSH was also extended to support application specific ROMFS
    /etc/init.d/rcS start-up scripts.  This feature, as well, as
    all of the above-mentioned apps/ directory support was contributed
    by Uros Platise
  * Additional NSH improvements and bug fixes.  See the Changelog
    for details.
  * This release also provides a new SLIP network driver.  This
    driver should support point-to-point network communications to
    a host using TCP/IP or UDP.  This driver is code complete, but
    not tested in this release.
  * New RAMTRON FRAM driver (contributed by Uros Platise)
  * New generic 16550 UART driver.
  * Cortex-M3 Power improvements: Waits for Interrupt (WFI) in idle
    loop for reduced power consumption (LPC17xx and STM32 only -
    contributed by Uros Platise))
  * New waitpid() system interface.
  * Additional bugfixes: pipes, stdint.h, STM32 SDIO and SPI drivers

NuttX-6.0
^^^^^^^^^

The 67th release of NuttX, Version 6.0, was made on March 21, 2011
and is available for download from the SourceForge website.  The
version number of this release was bumped from 5.19 to 6.0.  A
change in the major revision number is used to reflect an incompatibility
with previous versions.  In this release, the NuttX core OS
functionality has been separated from NuttX application-related
functionality.  These are provided as separate tarballs:

  * nuttx-6.0.tar.gz, and
  * apps-6.0.tar.gz

The purpose of this separation is both to better organize and
modularize the NuttX source tree, but also to provide better support
for incorporation of end-user applications with Nuttx.

The incompatibility results from the changes to the board configuration
logic needed to supported the separable application.  The major
changes to the configuration include:

  * CONFIG_APPS_DIR - This should not be set.  The default is
    ../apps.  This should only be set if you have a custom,
    product-specific application directory in some different location.

  * appconfig - Each board configuration now requires a new file
    called 'appconfig.'  As its name suggests, this file provides
    new configuration information needed by the logic in ../apps.

In addition to this major reorganization in the directory structure,
this release also includes some important extensions to existing
features and some important bugfixes.  These include:

  * The SLIP driver was been well debugged and significantly
    re-designed.  Now you can have an Ethernet connection to you
    board even if you have no Ethernet hardware.  How cool is that?

  * The QEMU i486 port is now functional.  It has also been reported
    to work on the Bifferboard (see http://bifferos.bizhat.com/).

  * And extensions to the uIP driver interface, and

  * Bug fixes to fopen() and STM32 GPIO configuration

Please see the ChangeLog for details.

NuttX-6.1
^^^^^^^^^

The 68th release of NuttX, Version 6.1, was made on April 10, 2011
and is available for download from the SourceForge website.  The
6.0 release introduced a detach-able application environment to
build applications outside of the NuttX source tree.  The primary
purpose of this release is to correct numerous build problems
introduced by that architectural change:

  * In many newer environments, NuttX produced strange Makefile
    errors but built correctly in older environments.  A fix provided
    by Rafael Noronha was incorporated and is reported to fix those
    build problems.
  * The apps/ directory build system would not handle Windows-native
    toolchains due to obscure path formatting issues.
  * And other problems as detailed in the Changelog.

Many additional changes were made in the 6.1 release for another
major architectural change:  NuttX will now build as a separately
linked microkernel.  In this build option the RTOS builds as a
kernel, applications build separately and interface with kernel via
system calls.  Applications run in user mode and kernel logic users
in kernel-mode.  This provides a secure environment for NuttX.  This
feature is fully coded in NuttX-6.1, but has not been tested due
to higher priority tasks that have arisen.

Related to this change, support for the Cortex-M3 memory protection
unit (MPU) has been integrated with the NuttX kernel build to provide
an even higher level of security.

NOTE: This kernel build is an option; the default build configuration
is still the standard, flat, unsecured RTOS as in previous releases.

Additional new features in this release:

  * Support for LPC17xx GPIO interrupts (with much support from
    Decio Renno).
  * Basic timer support for STM32 (Contributed by Uros Platise)
  * A binfs file system.  This is a tiny pseudo file system that
    lets named applications to be viewed and accessed in NSH under
    the /bin directory.
  * An I2C-based driver for the LIS331DL MEMS motion sensor.
    (Contributed by Uros Platise.)
  * A configuration for the Embedded Artists LPCXpresso LPC1768 board.
  * The user_initialize() interface has been removed.

And several bugfix associated with SD drivers, opendir(), signed
8-bit types (int8_t), and USB serial device.  See the ChangeLog for
details.

NuttX-6.2
^^^^^^^^^

The 69th release of NuttX, Version 6.2, was made on May 6, 2011 and
is available for download from the SourceForge website.  The 6.2
release includes several new features:

  * NXFFS: The obvious new feature is NXFFS, the NuttX wear-leveling
    FLASH file system.   This new file system is intended to be
    small for the MCU usage and has some limitations.  No formal
    documentation of NXFFS yet exists.  See the fs/nxffs/README.txt
    file for details (see
    http://nuttx.svn.sourceforge.net/viewvc/nuttx/trunk/nuttx/fs/nxffs/README.txt?view=log)
  * Support for NXP LPCXpresso LPC1768 board on the Embedded
    Artists base board.  The Code Red toolchain is supported under
    either Linux or Windows.   Verified configurations include
    dhcpd, nsh, nx, ostest, thttpd, and usbstorage.
  * Support for the Univision UG-9664HSWAG01 OLED with Solomon
    Systech SD1305 LCD controller.
  * A new RAM MTD driver with FLASH simulation capability.
  * A version.h file is now automatically generated so that C code
      can now be version aware.

In addition to these new feature, several important bugfixes are
included in this release correcting problems with dup2(), LPC17xx
GPIO interrupts, LPC17xx UART2/3, the FAT file system, build issues,
and strrch().  See the ChangeLog for more details.

NuttX-6.3
^^^^^^^^^

The 70th release of NuttX follows only a nines days after the release
of version 6.2.  It was released on May 15, 2011.  This special
back-to-back release was made so that the current released version
of NuttX will correspond to the initial release from the RGMP
project.

This release adds architecture support and build configuration for
RGMP.  RGMP is a project for running GPOS and RTOS simultaneously
on multi-processor platforms. See
http://rgmp.sourceforge.net/wiki/index.php/Main_Page for further
information about RGMP.

This release also includes support for STM32 FLASH, build improvements,
and initial, incomplete support for the MicroChip PIC32MX MCU.  Bug
fixes are included for some build problems, USB host class driver
error handling, NX graphics color mapping, and problems with C
standard I/O buffer flushing.  See the ChangeLog for further details.

NuttX-6.4
^^^^^^^^^

The 71st release of NuttX, Version 6.4, was made on June 6, 2011
and is available for download from the SourceForge website.  The
6.4 release includes several new features:

  * A new, full-featured FTP client.  This client may be used as a library
    for automated FTP or via an FTP client shell.  The FTP shell
    supports the following commands: cd, chmod, get, help, idle,
    login, ls, quit, mkdir, noop, put, pwd, rename, rhelp, rm,
    rmdir, size, time, and up.  A configuration is available for
    the NXP LPC17xx to demonstrate this functionality.
  * A functional C1101 wireless driver (contributed by Uros Platise)
  * A PCI-based E1000 Ethernet driver (contributed by Yu Qiang)
  * New C library functions: inet_addr() (contributed by Yu Qiang),
    strndup(), asprintf()
  * Reduced memory allocation overhead for MCUs with small heaps (<64K).
  * fdopen() now works with socket descriptors allowing standard
    buffered C functions to be used for network communications.
  * The NSH ifconfig command can now be used to set or change the
    IP address (contributed by Yu Qiang)

This release also includes some completed but untested functionality.

  * The MicroChip PIC32MX port is now code complete and ready to
    begin testing.  Unfortunately, testing will be delayed due to
    tool issues.
  * Support for the NXP LPC315x MCUs.

Additional miscellaneous enhancements and bug fixes to task_delete(),
recvfrom(), and other changes as noted in the ChangeLog.

NuttX-6.5
^^^^^^^^^

The 72nd release of NuttX, Version 6.5, was made on June 21, 2011
and is available for download from the SourceForge website.  The
6.5 release is all about support for the Atmel 8-bit AVR family.
I have been interested in the AVR family for some time but because
of the severe SRAM constraints and because of the availability of
many tiny schedulers for the AVR, it has not been "on the radar
screen."  However, I have recently become interested because of
interest expressed by members of the forum and because of the
availability of newer, larger capacity AVR parts (that I don't have
yet).

This release includes support for the following AVR boards.  As
with any initial support for new architectures, there are some
incomplete areas and a few caveats that need to be stated.  Here
they are, ordered from the least to the most complete:

  * SoC Robotics Amber Web Server (ATMega128).

    This port of NuttX to the Amber Web Server from SoC Robotics
    (http://www.soc-robotics.com/index.htm).  Is only partially in
    place.  The Amber Web Server is based on an Atmel ATMega128
    (128K FLASH but only 4K of SRAM).

    STATUS: Work on this port has stalled due to toolchain issues.  It
    is complete, but untested.

  * Micropendous 3 AT9USB647

    This port of NuttX to the Opendous Micropendous 3 board. The
    Micropendous3 may be populated with an AT90USB646, 647, 1286,
    or 1287.  See http://code.google.com/p/opendous/. I have only
    the AT90USB647 version for testing.  This version has very
    limited memory resources: 64K of FLASH and 4K of SRAM.

    STATUS: The basic port was released in NuttX-6.5.  This basic
    port consists only of a "Hello, World!!" example that demonstrates
    initialization of the OS, creation of a simple task, and serial
    console output.  The tiny SRAM limits what you can do with the
    AT90USB647 (see issues below).

  * PJRC Teensy++ 2.0 AT9USB1286

    This is a port of NuttX to the PJRC Teensy++ 2.0 board.  This
    board was developed by PJRC (http://pjrc.com/teensy/). The
    Teensy++ 2.0 is based on an Atmel AT90USB1286 MCU with 128K
    of FLASH and 8K of SRAM; a little more room to move than the
    AT90USB647.

    STATUS:  The basic port was released in NuttX-6.5.  This basic
    port consists of a "Hello, World!!" example and also slightly
    simplified NuttShell (NSH) configuration (see the NSH User Guide
    at http://www.nuttx.org/NuttShell.html).

    An SPI driver and a USB device driver exist for the AT90USB as
    well as a USB mass storage configuration.  However, this
    configuration is not fully debugged as of the NuttX-6.5 release.

AVR-specific issues.  The basic AVR port is solid and biggest issue
for using AVR is its tiny SRAM memory and its Harvard architecture.
Because of the Harvard architecture, constant data that resides to
flash is inaccessible using "normal" memory reads and writes (only
SRAM data can be accessed "normally").  Special AVR instructions
are available for accessing data in FLASH, but these have not been
integrated into the normal, general purpose OS.

Most NuttX test applications are console-oriented with lots of
strings used for printf and debug output.  These strings are all
stored in SRAM now due to these data accessing issues and even the
smallest console-oriented applications can quickly fill a 4-8K
memory.  So, in order for the AVR port to be useful, one of two
things would need to be done:

1. Don't use console applications that required lots of strings.
   The basic AVR port is solid and your typical deeply embedded
   application should work fine.

2. Create a special version of printf that knows how to access
   strings that reside in FLASH (or EEPROM).

NuttX-6.6
^^^^^^^^^

The 73rd release of NuttX, Version 6.6, was made on July 11, 2011
and is available for download from the SourceForge website.  The
6.6 release adds several smaller features but is mostly a bugfix
release.

Bugfixes include

  * Fixed several NX Graphics bugs: Rendering fonts at >8 bits-per-pixel,
    graphics move logic, and display artifacts that appear when a
    window is closed.
  * Corrections to the USB host mass storage class driver
  * STM32 bugfixes: serial driver, GPIO interrupt handling
  * LPC17xx: Changes for a success compilation with no console.
  * Corrections to the Teensy AT90USB SD driver
  * Changes for a clean compilation under the ZDS-II toolchain.

Minor features:

  * Add logic to extract printf strings from FLASH (but there are
    still printf issues for that target)
  * Added a configuration for the Sure Electronics PIC32MX board.
    However, higher priority tasks have stopped work on that
    configuration.
  * Added several new configurations for the STMicro STM3210E-EVAL
    board.
  * Added support for the STM3210E-EVAL board: (1) LCD in either
    landscape or portrait mode, and (2) interrupting buttons.
  * Added a configuration option to use different serial ports for
    debug and for the NSH serial console (there are some issues
    with CR-LF expansion and character echo if NSH is not run on
    the console).
  * Standardized the button press and button interrupt interfaces
    so that they are common across all boards.
  * Added a new graphics example that focuses on placing text on
    the background while pop-up windows occur.  Text should continue
    to update normally with or without the popup windows present.
  * Added ARM stack checking logic.

See the ChangeLog for a detailed description of these changes.

NuttX-6.7
^^^^^^^^^

The 74th release of NuttX, Version 6.7, was made on August 2, 2011
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.7.tar.gz and
apps-6.7.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).  Changes in this release are summarized
below:

  * New OS APIs: Add the standard sem_timedwait() interface.
  * FAT File System:  Adds (optional) support for VFAT long file
    names.
  * USB:  Now the mass storage device can be connected when needed
    and disconnected when not needed (or re-connected as a different
    kind of device).
  * Touchscreen Support:  Defined a new NuttX touchscreen interface.
    Added a driver for the TI TSC2007 touchscreen controller chip.
  * NX Fonts:  Add support for multiple fonts; developed a tool to
    convert open source fonts into NuttX format; Converted and
    installed nine new, high quality fontsets.
  * NX Graphics: Add new NX APIs to support drawing of wide lines
    in any orientation.  Added new low level routines to set
    individual pixel more efficiently.
  * Build system:  Added a export target that will bundle up all
    of the NuttX libraries, header files, and the startup object
    into an exportable tarball.
  * LPC17xx: A CAN driver was contributed by Li Zhuoyi (Lzyy).
  * STM32: New NX-related configurations to exercise text and
    graphic image displays.
  * C Library:  Added a fixed precision atan2() math function.
  * Bugfixes:  Serial RX overrun error, FAT upper/lower NT 8.3 name
    handling fixed.  FAT directory allocation and initialization
    bug.  STM32 SDIO DMA race condition bug.  eZ80 UART1 serial
    driver errors (Paul Osmialowski)

NuttX-6.8
^^^^^^^^^

The 75th release of NuttX, Version 6.8, was made on August 19, 2011
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.8.tar.gz and
apps-6.8.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).  Changes in this release are summarized
below:

  * NuttX has been ported to run on the Freescale Cortex-M4 "Kinetis"
    boards.  Two board ports are available for (1) the Kinetis
    KwikStik-K40 and (2) the Kinetis TWR-K60N512 tower.
  * Support for RGMP 0.3.  This version of RGMP now runs on the
    OMAP4430 (arm) pandaboard
  * LPC17xx CAN driver extended to support both CAN1 and CAN2
    (submitted by Li Zhuoy (Lzzy))
  * Fixed several critical bugs related to signal handling
    initialization and for signals the wake up tasks that are waiting
    to send or receive message queues.Both are important.  (submitted
    by hkwilton).
  * drivers/can.c:  Fixed a semaphore overflow problem in the CAN
    driver (reported by Li Zhouy (Lzzy)).
  * Added a new ADC driver infrastructure and TI ADS1255 driver
    both developed and submitted by Li Zhouy (Lzzy)).

See the Changelog for additional changes included in this release.

NuttX-6.9
^^^^^^^^^

The 76th release of NuttX, Version 6.9, was made on September 11, 2011
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.9.tar.gz and
apps-6.9.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release includes a few new features and several important bug fixes.
The new features (some still incomplete) include:

  * Analog Support/ NXP LPC17xx: New DAC sub-system including ADC and DAC
    drivers for the LPC17xx.  Extensions to the ADS1255 driver.
    (Contributed by Li Zhuoyi (Lzyy))

  * Power Management:  Added a new NuttX power management sub-system for
    controlling and coordinating reduced power states.  At present, only
    verified in a simulation environment.

  * I2C Test Tool:  A new application was added that can be used to
    verify and debug I2C interfaces from the NuttShell (NSH) command
    line.

  * NuttShell (NSH):  In addition to the I2C test tool, a date command
    is now supported (if CONFIG_RTC is defined) that can be used to
    read and set the RTC.

  * NXP LPC17xx: I2C and DAC driver for the NXP LPC17xx family submitted by Li Zhuoyi
   (Lzyy)

  * Kinetis Cortex-M4:  Added a SDHC driver for the Kinetis parts.
    Complete debug of the Kinetis SDHC driver was not completed, however,
    do to some higher priority tasks that forced me to stop work.

  * Other new drivers: Driver for I2C-based at24cxx EEPROM submitted by
    Li Zhuoyi (Lzyy); Driver for the LM-75 temperature sensor.  Support
    for the LM-75 temperature sensor integrated into the SM3210E-EVAL
    development board.

  * NuttX Graphics (NX):  Added new NX interfaces for drawing circles,
    both circle outlines and filled circles.

  * FLASH: Added a function that accepts the path to a block driver and
    then erases the underlying FLASH memory

  * Build System:  The Make export logic now also tries to track down all
    architecture-specific header files and include these in the NuttX
    export bundle as well.  Various changes and modifications so that
    NuttX wil build on FreeBSD using the ASH shell (submitted by Kurt Lidl).

Bugfixes, order roughly on decreasing criticality include:

  * STM32 I2C Driver:  Add resets, timeout, and other fixes to work
    reliably with the I2C tool.  Corrected a major error introduced in
    NuttX 6.8.

  * BCH Driver.  Several important bugs (noted by Li Zhuoyi (Lzyy))
    were fixed.

  * C Library:  Fixed errors in gmtime() and gmtime_r() that could lead to
    errors in date calculations.

  * Timing:  Correct an error in the tv_nsec calculation that happens
    only config CONFIG_RTC is enabled

  * Build System: Use of -print-libgcc-file-name to get path to
    libgcc.a might select the wrong libgcc.a if a multilib toolchain
    is used

NuttX-6.10
^^^^^^^^^^

The 77th release of NuttX, Version 6.10, was made on October 6, 2011
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.10.tar.gz and
apps-6.10.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r4028

This release includes a few new features and several important bug fixes.
The new features (some still incomplete) include:

  * CDC ACM serial class device-side driver

  * RTC:  Now supports hi-res and lo-res hardware RTC.  The lo-res RTC
    runs at 1Hz.

  * STM32 I2C driver.  Now supports faster, polled mode of operation.
    Added an I2C trace capability.

  * ADS7843E touchscreen driver.  As used on the SAM3U-EK development
    board.

  * AT91SAM3U SPI driver.  To support the ADS7843E toucscreen

  * X11 Support on simulation target.  Build errors in the X11 windows
    for the simulated target have been correct.  Added support for a
    simulated touchscreen on the X11 window (based on mouse inputs).

  * System Timer. Added support for a 64-bit system timer.

  * TIFF Support. Added a TIFF library (currently used for storing
    LCD screen shots).

  * LCD Support.  Added a test to verify that we read and write correct
    to LCD GRAM memory.

  * I2C tool. Extended to support to include a verify command and
    repititions and auto-address increment for most commands.

  * USB terminal example.  Line oriented serial bridge connects a host
    USB serial terminal to a host UART serial terminal.

  * Build System.  apps/ Makefile will now include external directories
    in the application build.

Bugfixes, order roughly on decreasing criticality include:

  * Message Queues.  Correct errors in mq_timedsend() and
    mq_timedrecieve().

  * FAT. Writes that cross sector boundaries, stray write into the FAT,
    and a FAT long file name issue

  * NXFFS.  Added a missed error check.  Files cannot be opened for
    writing if they are already opened for reading.

  * Library: fopen() for append modse was not appending.

  * STM32 I2C driver.  Correct another conflict between concurrent FSMC
    and I2C1 accesses.  Fixed some bad error detection logic.

  * STM32 SDHC driver.  Interrupts were being left disabled.

NuttX-6.11
^^^^^^^^^^

The 78th release of NuttX, Version 6.11, was made on November 12, 2011
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.11.tar.gz and
apps-6.11.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r4090

This release is a maintenance release that includes a few new features
and some important bugfixes.  New features include:

    * NX Graphics:  New interfaces to read from graphics memory
    * Drivers:  AT24 FLASH driver will now supports clustering of blocks
      to achieve a larger, more usable block size for NXFFS.
    * STM32: LCD color corrections
    * PIC32: Board configuration for the Microchip PIC32 Ethernet Starter kit
      (not yet verified), new GPIO support library, button and LED support
      for the Sure Electronics PIC32MX board.  A lot of progress has been
      made on the PIC32 NuttX port, but it is still not ready for prime time.
    * NXP LPC3152: Board configuration for the Embedded Artists EA3152.

Bugfixes, order roughly on decreasing criticality include:

    * NXFFS: Corrected critical bugs in initialization, some full FLASH handling,
      and errors in certain cases where the FLASH is repacked.
    * ARM EABI: Fix stack aligment required for passing floating point values.
    * Build system: Fix build issues when g++ is used as the compiler.
    * NX Graphics: Bitmap error handling, correct RGB color conversion macros,
      Error when the background window is released.
    * STM32: RTC build fixes, LCD color corrections
    * Simulation target: build fixes
    * C Library: fclose() return value.

See the change log for more detailed information.

NuttX-6.12
^^^^^^^^^^

The 79th release of NuttX, Version 6.12, was made on December 6, 2011
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.12.tar.gz and
apps-6.12.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r4141

New features in this release include:

    * STM32. Basic support added for the STM32 F4 family.  Board support
      verified for the STMicro STM3250G-EVAL board.
    * FAT.  Enhanced partition handling.
    * SDIO-Based SD Card support.  Add support for large (>4Gb) devices
    * Graphics.  Added four new small sans serif fonts.
    * Drivers. Fix a banding problem with the R61580 LCD.

Bugfixes, order roughly on decreasing criticality include:

    * FAT. Fix errors in how the first entries in the root directory are
      added.  Fix errors in FAT date/time handling.
    * Signals.  Fix bug in certain sig_timedwait() error handling.
    * Drivers. Fix cloned errors in poll() handling in several drivers.
    * Message Queues.  errno was not being set correctly by mq_notify().
    * C Library. wchar_t is a built-in type for C++

NuttX-6.13
^^^^^^^^^^

The 80th release of NuttX, Version 6.13, was made on December 26, 2011
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.13.tar.gz and
apps-6.13.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r4231

New features in this release include:

    * Drivers. New standard interface for PWM drivers and common
      "upper half" PWM driver.  Updated the MP25x driver to support
      the Macronix MX25 chips (submitted by Mohammad Elwakeel).
    * STM32 F1/F4.  Added an Ethernet driver, ADC drivers, DAC driver,
      PWM driver, CAN driver, F4 RTC driver, F4 DMA support,
      logic for saving/restoring F4 FPU registers in context switches.
    * STM32 Boards.  Added STM3240G-EVAL DHPCD and nettest configuration.
      Support for a new STM32 board, the HY-Mini STM32v board, was
      contributed by Laurent Latil
    * PIC32.  The port to the Microchip PIC32MX is finally functional and
      reliable.  The NuttX PIC32 port has verified configurations for
      the OS test and the NuttShell (NSH) both exist.
    * Tests:  New re-usable tests (in apps/examples) for PWM, ADC, and
      CAN loopback.  Several existing tests can now be built as NSH built-in
      applicaitons (dhcpd, nettest, and all of the new tests).

Bugfixes, order roughly on decreasing criticality include:

    * STM32:  Correct handling of data overrun conditions.  Existing logic
      would hang with infinite interrupts when a data overrun occurred.
    * DHCPD.  Fix several problems using host order address where network
      addresses expected (and vice versa).

And several others.  See the ChangeLog for more details.

NuttX-6.14
^^^^^^^^^^

The 81st release of NuttX, Version 6.14, was made on January 15, 2012,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.14.tar.gz and
apps-6.14.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r4301

New features in this release include:

    * Drivers. The upper-half PWM driver will now support a pulse count (as
      would be needed to control a stepper motor).

    * STM32.  The CAN driver has been verified in loopback mode.  ADC driver
      support for the STM32 F4.  Add support for UART4-5 and USART6
      (Contributed by Mike Smith).  The PWM driver now supports a pulse
      count for TIM1 and TIM8.  Timer driver now supports the F4's 32-bit
      timers (Contributed by Mikhail Bychek)

    * STM32F4Discovery.  Support for the STM32F4-Discovery board contributed
      by Mike Smith.

    * STM3240G-EVAL.  Add support for user control of LEDs.

    * LPC17xx.  Add support for loopback mode to CAN driver.  CAN TX done 
      perations are now interrupt driver.  Now supports configurable CAN bit
      rate.

    * LPC1766-STK. Add support for on-board buttons. Add support for user
      control of LEDs.

    * LM3S.  Add support for the LM3S6432S2E on the TI RDK-S2E (Contributed
      by Mike Smith)

    * PIC32MX.  USB device-side driver (needs further testing).  A partial
      Ethernet driver is also in place.

    * Library. Support added for fixed floating point fieldwidths in output
      formatting (Contributed by Mikhail Bychek)

    * Build.  New targets apps_clean and apps_distclean to simplify working
      with application diretories.

Bugfixes include:

    * Drivers.  Fixed a buffer-full test in the upper-half CAN driver.

    * STM32.  GPIO initialize logic (submitted by Mike Smith).  Fix the
      debug logic that dumps the GPIO configuration.

    * LPC17xxx.  Correct an integeter overlow in GPIO interrupt setup
      (prevented pins > 15 from being used as interrupt sources).  Correct
      a value used in GPIO interrupt number range test.

    * FAT.  Now returns the correct error value when it is unable to
      recognize the file system.

    * Build.  MAC OS build fixes (submitted by Mike Smith)

And several others.  See the ChangeLog for more details.

NuttX-6.15
^^^^^^^^^^

The 82nd release of NuttX, Version 6.15, was made on February 12, 2012,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.15.tar.gz and
apps-6.15.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r4387

New features and extended functionality:

    * General Drivers:  Add support for (29-bit) extended CAN IDs.  Add an
      infrastructure to support battery drivers.   Add a driver for MAX17040x
      battery "fuel gauge".  Add support for Composite USB drivers (in
      particular for a CDC/ACM with MSC USB composite driver).

      Added a new RAM logging driver.  This will allow debug output into
      a RAM buffer associated with a character driver at /dev/syslog.
      Added the new command 'dmesg' to NSH that can be used to dump the
      current contents of the log.  This is useful for systems that do not
      have the usual serial console (for example, if you only have a
      Telnet console with NSH).

    * Networking:  Add a lower level, primitive socket interface.  Telnet
      driver:

      A New Telnet daemon was created.  It wraps a Telnet session within a
      character driver that can serve as a "controlling terminal."  The
      Telnet session will then be inherited by tasks created from the
      Telnet session and the stdin/stdout from the created task will
      still go through the same Telnet connection.

    * STM32 Drivers.  PWM driver pulse count was limited to 128; now is
      (essentially) unlimited.  Add support for (29-bit) extended CAN IDs.
      Add support for I2C3.  The SDIO driver is (mostly) verified on the
      STM32 F4 platforms.

    * LPC17xx Drivers.  Extended the CAN driver so that the TSEG1 and TSEG2
      bit times can be set via the NuttX configuration.  Add support for
      (29-bit) extended CAN IDs.

    * PIC32 Drivers. The PIC32 Ethernet driver is code complete (but still
      untested).

    * FTPD.  Add a new FTP server daemon.  This is based loosely on 
      the hwport_ftpd library provided by Jaehyuk Cho.

    * Library:  Add support for on_exit().  Implemented tcsetattr() and
      tcgetattr().  Moved the old, too-smart fgets() to a new application
      library function called readline().  Dumbed down the original fgets().
      Add strcasestr(), avsprintf(), inet_ntop(), and inet_pton().
      Add support to enable or disable debug output.

    * Build system: Support for building a 32-bit simulation executable on
      a 64-bit Linux machine.  Correct a dependency issue in the arch/*/src/board
      directory.

Bugfixes:

    * System:  Correct PTHREAD_MUTEX_INITIALIZER

    * FAT: Fix an error in the FAT statfs() reported by David Sidrane.

    * STM32: Fix clock frequencies for APB2 timers.  Correct AFIO register
      offset.

    * PIC32.  Correct GPIOs used for LEDs on the Sure PIC32MX board.

    * NSH.  Wait for a USB connection if a USB serial class is used to
      interface with the host.

Additional bugfixes, name changes, and other differences as detailed in the
ChangeLog.

NuttX-6.16
^^^^^^^^^^

The 83rd release of NuttX, Version 6.16, was made on March 10, 2012,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.16.tar.gz and
apps-6.16.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r4475

New features and extended functionality:

    * ARMv7M Support:  Includes new, streamlined Cortex-M exception
      handling provided by Mike Smith.  Context switching support for the
      Cortex-M4 FPU registers is now provided (in both "lazy" and "non-lazy"
      modes)

    * General Drivers: Added a generic "upper half" Quadrature Encoder driver.
      The USB CDC/ACM serial driver can now be dynamically connnected or
      disconnected from the host (programmatically or using NSH commands).

    * STM32 Drivers: Added a "lower half" Quadrature Encoder driver.
      Verified the STM32 F4 DMA driver; Added F4 DMA support to the existing
      STM32 SDIO driver.

    * STM32 Board Support.  Added support for the STM32 F2 family and
      for the STM3220G-EVAL board (contributed by Gary Teravskis).
      Support is now included for C++ static constructors (verified using
      the Atollic toolchain). Added support for the SRAM available on the
      STM3240G-EVAL board.

    * PIC32 Drivers.  PIC32MX USB (device) driver is now functional.
      The PIC32MX Ethernet driver not yet fully verified (and an
      unverified SPI driver is also available).

    * Networking.  Added a lower-level, thread-independent socket layer.
      Parts of this layer were created in 6.15 to support the FTPD
      controlling terminal; this support has been extended in order
      to support an NFS file system (not yet released).

    * NuttShell (NSH).  NSH will now support a USB serial connection for
      the console (such as CDC/ACM).  This is useful in environments
      where there is no physical serial port on the board.

    * Build System.  Reorgnaization of networking header files.

Critical Bugfixes.  The following bug fixes are considered critical:

    * Networking:  Fixed a "leak" in the TCP/IP read-ahead buffering logic.
      Corrected an error in TCP/IP sequence numbering/ACK logic which
      occurred when read-ahead buffering memory is exhausted.

    * STM32 Drivers: Fixed an buffer sizing error in the STM32 Ethernet
      driver.

Additional Bugfixes:  Other important bug fixes are listed below. See
the ChangeLog of a complete, detailed list of bug fixes.

    * Networking: Corrected recv()/recvfrom() return value.  Added logic to
      monitor for loss of connection after a new connection has been
      established via accept() (Contributed by Max Nekludov).  Add
      logic to select() to correctly handle POLLHUP (Contributed by Max
      Nekludov)

Additional bugfixes, name changes, and other differences as detailed in the
ChangeLog.

NuttX-6.17
^^^^^^^^^^

The 84th release of NuttX, Version 6.17, was made on April 14, 2012,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.17.tar.gz and
apps-6.17.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r4607

New features and extended functionality:

    * Networking:  Additional low-level, thread-independent socket
      interfaces (for NFS client support).

    * RTC:  Added a new interface call clock_synchronize().  This function
      will reload the system time from an RTC and is required when the
      system re-awakens from certain deep-sleep modes.

    * Graphics:  Add NxConsole.  This is a character device driver that
      wraps an NX window and can be re-directed for stdout.  This allows,
      for example, a pop-up graphics window that contains a NuttShell (NSH)
      session.  A test of NxConsole is available at apps/examples/nxconsole.

    * Watchdog Drivers:  Added an interface definition an "upper half"
      driver to support watchdog timers.

    * Calypso:  Support for TI Calypso-based cellphones (as supported by
      the Osmocom-BB project) was contributed by members of the Osmocom-BB
      team.  This includes configurations for the Compal e88 and e99 phones.

    * USB Device Interface:  Needed to extend the USB device interface
      because there was no mechanism for passing endpoint OUT data that
      may need to accompany a setup request.

    * STM32 drivers:  Added some power management controls for entering
      reduced power consumption states.  An OTG FS driver was completed
      and partially verified (this driver seems to be functional but since
      it has been test so lightly, it might better be listed in the
      next section "Work in progress").

    * PIC32 drivers: The PIC32 Ethernet driver is now stable.  The PIC32
      USB device controller driver is now functional (but not yet stable).

    * PIC32 boards: Added support for the Sure DB-DP11212 PIC32 General
      Purpose Demo Board.  There is now a PIC32 Starter Kit that
      provides NSH only through a Telnet connection.

    * Build System:  Some header files were moved into include/nuttx.
      The goal is to move any non-standard header files to include/nuttx
      or include/arch.  Moved include/math.h to include/nuttx/math.h;
      this file is now only instantiated as the 'system' math.h if
      CONFIG_ARCH_MATH_H=y is defined.

    * Tools:  Added tools/cmpconfig.c, a tool for comparing two
      configuration files.

Work in progress.  This release includes some partially completed
work that is still not ready for prime time.

    * NFS Client:  Work is progressing on support for an NFS client
      file system.    This is a port of the BSD NFS client file system
      that is being done by Jose Pablo Rojas V.

    * Automated Configuration:  Automated configuration based on the
      kconfig-frontends tool is being incorporated into the build
      system.  The configuration is still not complete enough for
      general use in this release.

    * STM32 Drivers:  Added files that will (eventually) hold an STM32
      OTG FS host driver.  This is still a work in progress.

Bugfixes:

    * Networking:  Corrected a deadlock that only occurred when
      executing the NSH 'ifconfig' command over Telnet.

    * File system:  Fix incorrect return errno value from read() when
      the file is opened write-only.

    * Graphics:   Fix several compilation errors that have crept into the
      multi-user NX server because of lack of use.

    * STM32:  In order to use CAN2, both CAN1 and CAN2 clocking must be
      enabled. Fixed a troublesome bug in the STM32 F4 I2C driver that
      resulting in timeouts.

    * LPC17xx: Fixes for errors the crept in the LPC17xx DAC logic
      Contributed by Lzyy).

    * Build System:  Reordered the link command line to account for new
      versions of libgcc.a that require symbols from the application
      (abort()).

NuttX-6.18
^^^^^^^^^^

The 85th release of NuttX, Version 6.18, was made on May 19, 2012,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.18.tar.gz and
apps-6.18.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

The majority of changes in this release are focused on supporting the
synchronized release of NxWM, the NuttX tiny window manager.  That
window manager is released as part of the NxWidgets package, but depends
upon many of the changes in this NuttX release.

This release corresponds with SVN release number: r4751

New features and extended functionality:

    * Drivers.  Added a watchdog timer driver infrastructure.  Add general
      support for STMicro STMPE811 I/O Expander/touchscreen device.

    * STM32. Add support for the STM32 IWDG and WWDG watchodog timers.  DMA
      now supports cicular buffer mode; serial driver now uses circular
      DMA to improve Rx performance (Contributed by Mike Smith).

    * STM3240G-EVAL Board.  Add support for the LCD and for the STMPE811
      I/O Expander as a touchscreen controller.

    * PIC32 Boards.  Board support for the Mikroelektronika PIC32MX7
      Multimedia Board (MMB) and for the Sparkfun UBW32 PIC32 board.

    * NX. Framed windows are now draw in three colors instead of just two.
      Numerous other extensions needed to support NxWM (see the ChangeLog
      for details).

    * Library. Add prctl() command that can be used to setting and getting
      the names of threads.  This (plus several other improvements and bug
      fixes) are part of a larger effort to improve task monitoring
      capabilities.

Work in progress.  This release includes some partially completed
work that is still not ready for prime time.

    * NFS Client. Work is progressing on support for an NFS client
      file system.   This is a port of the BSD NFS client file system
      that is being done by Jose Pablo Rojas V.

    * Automated Configuration. Automated configuration based on the
      kconfig-frontends tool is being incorporated into the build
      system.  The configuration is still not complete enough for
      general use in this release.

    * STM32 Drivers. Added files that will (eventually) hold an STM32
      OTG FS host driver.  This is still a work in progress.

Bugfixes (see the change log for details) :

    * sched_setscheduler() return value (Contributed by Richard Cochran).

    * stdio. Ignore CONFIG_STDIO_LINEBUFFER if the file was opened in binary mode.

    * fopen(). Correct an error in parsing open mode string.

    * serial driver. Improved performance be reducing the amount of time
      that Rx interrupts are disabled.

    * recvfrom(). Fix a compilation problem.

    * CDC/ACM device driver. Fix an infinite loop that occurs when the serial
      device is unregistered.

    * STM32 OTG FS device driver. Numerous fixes and the driver is partially
      functional but there are still some issues that become apparent when
      debug output is disabled.

    * fcntl(). Always returned zero on success; however, some fcntl commands
      need to return non-zero values on success.

    * graphics:  Many multi-use mode fixes added to support NxWM (see the
      ChangeLog for details).  Auto-raise is temporarily disabled in multi-
      user mode because it causes some problems with NxWM.

    * on_exit():  Fix compilation errors if CONFIG_SCHED_ONEXIT is enabled.

NuttX-6.19
^^^^^^^^^^

The 86th release of NuttX, Version 6.19, was made on June 15, 2012,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.19.tar.gz and
apps-6.19.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r4847

This release features new support for a Network File System (NFS) client.
This feature allows a tiny, embedded MCU to mount a remote file system
exported by an NFS server and then to access the file system as it would
any local file system.  Then the tiny MCU can effectively have terabytes
of storage!

This might be useful for data collection, for MCU configuration information,
for software updates, for providing modular, loadable code modes, controlling
a "farm" of MCUs, ... there are many possibilities and opportunities for
innovation!

The NuttShell (NSH) now supports the following command:

  nfsmount <server-address> <mount-point> <remote-path>

That command will mount the remote NFS server directory <remote-path> at
<mount-point> on the target machine.  <server-address> is the IP address of
the remote server.

The NFS development was the graduation project of Jose Pablo Rojas V. who
is a student at the Instituto Tecnológico de Costa Rica (ITCR, or TEC).
A lot of effort went into understanding what a tiny, embedded NFS client should
do and getting the target resource usage to a bare minimum.  Only around a
kilobyte or so of memory is required to run the NFS client (and most of that
for I/O buffers).  Jose Pablo has spent several months living with NFS and
should be congratulated.

Additional new features and extended functionality:

    * Drivers:  SSD1289 LCD driver, MIO283QT2 LCD driver

    * LM3S: Additional register definition header files (contributed by Max
      Neklyudov).

    * STM32 Boards:  The STM32F4Discovery will now support an SSD1289 LCD,
      The STM3220G-EVAL board support is now equivalent to the STM3240G-EVAL
      board support.

    * PIC32 Boards: The Mikroelektronika PIC32MX7 MMB board port is now
      functional, very complete, and stable.

    * Graphics:  The NxConsole will now take keyboard input from the NX graphics
      subsystem.  This means that if there are multiple NxConsole windows, only
      the top instance that has focus will receive the keyboard input.

    * apps/:  Add the capability to use an arbitrary USB device as the console
      (not necessarily /dev/console).  Additional enhancements for USB consoles.
      Added the 'mv' command.

Work in progress.  This release includes some partially completed
work that is still not ready for prime time.

    * Automated Configuration. Automated configuration based on the
      kconfig-frontends tool is being incorporated into the build
      system.  The configuration is still not complete enough for
      general use in this release.

    * STM32 Drivers. Added files that will (eventually) hold an STM32
      OTG FS host driver.  This is still a work in progress.

Bugfixes (see the change log for details) :

    * General:  sleep() and usleep() return values, sig_timedwait() errno setting
      on timeout.
    * Drivers: STMPE811 touchscreen driver, USB PLC2303, USB CDC/ACM
    * STM32: Several USB device controller driver fixes, F4 interrrupt priorities
      (contributed by Mike Smith).
    * Graphics: Keyboard input, fill trapezoid bug

As well as other, less critical bugs (see the ChangeLog for details)

NuttX-6.20
^^^^^^^^^^

The 87th release of NuttX, Version 6.20, was made on July 12, 2012,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.20.tar.gz and
apps-6.20.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r4937

Additional new features and extended functionality:

    * Power Management:  An evolving power management example is being
      created by Diego Sanchez.  This effort currently involves on the 
      STM32 F1 but clearly demonstrates the NuttX power management
      system which will automatically drive the system to lower power
      usage states due to lack of use.

    * Drivers:  Added a driver for the SST 25 SPI-based FLASH parts.

    * PIC32:  Added support for the PIC32MX1 and PIC32MX2 families.
      Added support for the microchipOpen and Pinguino toolchains.

    * NXP LPC43XX: Added support for the entire LPC43xx family

    * PIC32 boards:  Added support for the DTX1-4000L "Mirtoo" module
      from http://www.dimitech.com/ (PIC32MX2).

    * NXP LPC43XX Boards: Added support for NGX LPC4330-Xplorer board.

    * NXP LPC17XX Boards: Added support for Micromint Lincoln60 board
      (LPC1769).

    * LM3S Boards:  Add a configuration to support the TI/Stellaris
      EKK-LM3S3B96 development board.  Contributed by Jose Pablo Rojas V.

    * Library:  NuttX now supports platform-specific stdarg.h header
      files.

Work in progress.  This release includes some partially completed
work that is still not ready for prime time.

    * Automated Configuration. Automated configuration based on the
      kconfig-frontends tool is being incorporated into the build
      system.  The configuration is still not complete enough for
      general use in this release.

    * STM32 Drivers. Added files that will (eventually) hold an STM32
      OTG FS host driver.  This is still a work in progress.

Bugfixes (see the change log for details) :

    * PIC32: GPIO output configuration (critical bug)
    * STM32: Typos in pin mapping files.
    * LM3S:  Fixed an optimization related but that caused slow start-up
      times if optimization was disabled.
    * Library:  Fixed signed extension but in all limit.h files
      (reported by Lorenz Meier).  inet_ntoa compilation failure
      on Z80.

As well as other, less critical bugs (see the ChangeLog for details)

NuttX-6.21
^^^^^^^^^^

The 88th release of NuttX, Version 6.21, was made on August 25, 2012,
and is available for download from the SourceForge website.  Note
that release consists of two tarballs:  nuttx-6.21.tar.gz and
apps-6.21.tar.gz.  Both may be needed (see the top-level nuttx/README.txt
file for build information).

This release corresponds with SVN release number: r5052

Additional new features and extended functionality:

    * Core: Add support for multiple registered atexit() functions.  Syslog
      extended:  Now any character driver may be used for the debug logging
      device.  Mountpoint traversal logic.
    * Drivers: Added support for the TI PGA112-7 amplifier/multiplexor.
    * LPC43xx:  Added clock ramp-up logic to run at 204 MHz
    * LPC43xx Drivers:  SPIFI block driver, RS-485 support, Minimal termios
      support.  Framework for USB0 device controller driver.
    * LPC17xx Drivers:  Minimal termios support
    * STM32: Support for STM32 F1 "Value Line" (contributed by Mike Smith).
      Add support for STM32 F107 "Connectivity Line" (contributed by Max
      Holtzberg).
      Clock restart logic needed for recovery from low power modes.
    * STM32 Drivers:  RTC alarm support.  Usable for wakeup from sleep mode,
      Minimal serial termios support.  USB OTG FS host driver (alpha).
    * STM32 Boards: Add power management hooks for the STM32F4Discovery,
      Add support for the Olimex STM32-P107 (contributed by Max Holtzberg).
    * PIC32:  Add support for the Pinguino MIPS toolchain.
    * PIC32 Drivers:  GPIO driver now supports F1 analog regiaters (ANSEL).
    * PIC32 Boards: Add support for the PGA117 on the Mirtoo module.
    * Calypso:  Add support for the SSD1783 LCD on the Compal E99.
    * Library:  cfsetispeed(), cfsetospeed(), tcflush(), memchr(), and
      memccpy().
    * Applications:  Port of freemodbus-v1.5.0. Add support for testing
      devices with multiple ADC, PWM, and QE devices.  
      NSH: NSH 'mount' command (with no arguments) will now show mounted
      volumes.  Add new NSH 'df' command.  Extended 'help' support. NSH
      now catches the return value from spawned applications (provided
      by Mike Smith).
    * Build System: mkconfig will not define CONFIG_DRAM_END.  A lot of 
      progress has been made on the automated NuttX configuration logic
      (Thanks go to Richard Cochran).
    * Documentation: Document ways to customize the behavior of NSH.

Bugfixes (see the change log for details) :

    * Serial drivers (all): Fix ioctl return value. Common "upper half"
      serial driver will now return with EINTR if a serial wait is
      interrupted by a signal.
    * FAT: Fix statfs() file name length.
    * LPC43xx: Clock configuration.
    * STM32: Pinmap fixes, SPI driver re-initialization
    * STM32 Boards: Correct and lower SDIO frequency for F2 and f4 boards.
    * AVR: C++ build issues.
    * PM: Fix a place where interrupts were not be re-enabled.
    * Applications: NSH application start-up race conditions.
    * Library: Fieldwidth and justification for %s format.  Fixed several
      issues with presenting floating point numbers.  NULL definition
      for C++

As well as other, less critical bugs (see the ChangeLog for details)