diff options
Diffstat (limited to 'nuttx/arch/c5471/src/up_fullcontextrestore.S')
| -rw-r--r-- | nuttx/arch/c5471/src/up_fullcontextrestore.S | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/nuttx/arch/c5471/src/up_fullcontextrestore.S b/nuttx/arch/c5471/src/up_fullcontextrestore.S new file mode 100644 index 0000000000..c4b230316c --- /dev/null +++ b/nuttx/arch/c5471/src/up_fullcontextrestore.S @@ -0,0 +1,115 @@ +/************************************************************************** + * up_fullcontextrestore.S + * + * Copyright (C) 2007 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name Gregory Nutt nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + **************************************************************************/ + +/************************************************************************** + * Included Files + **************************************************************************/ + +#include <nuttx/irq.h> +#include "up_internal.h" + +/************************************************************************** + * Private Definitions + **************************************************************************/ + +/************************************************************************** + * Private Types + **************************************************************************/ + +/************************************************************************** + * Private Function Prototypes + **************************************************************************/ + +/************************************************************************** + * Global Variables + **************************************************************************/ + +/************************************************************************** + * Private Variables + **************************************************************************/ + +/************************************************************************** + * Private Functions + **************************************************************************/ + +/************************************************************************** + * Public Functions + **************************************************************************/ + +/************************************************************************** + * Name: up_fullcontextrestore + **************************************************************************/ + + .globl up_fullcontextrestore + .type up_fullcontextrestore, function +up_fullcontextrestore: + + /* On entry, a1 (r0) holds address of the register save area */ + + /* Restore the volatile registers. This is not necessary for + * normally task-to-task context switches (where the context + * was saved by up_saveusercontext()), but is necesary when + * the full context was saved through interrupt handling. + */ + + /* Recover the user context (we will then have a new stack pointer) */ + + add r1, r0, #XCPTCONTEXT_UOFFSET + ldmia r1, {r3-r11, r13-r14} + + /* Save the CSPR value and one scratch register on the stack */ + + sub sp, sp, #2*4 /* Create a frame to hold two regs */ + stmia sp, {r3, r4} /* Save the CPSR (r3) and scratch (r4) */ + + /* Then recover the remaining registers */ + + ldmia r0, {r0-r3, r12} /* Recover volatile regs */ + + /* Now we can restore the CPSR (probably re-enabling interrupts) */ + + ldr r4, [sp] + msr cpsr, r4 + + /* Then recover the correct r4 value */ + + ldr r4, [sp, #4] + + /* Destroy the temporary stack frame and return */ + + add sp, sp, #2*4 + movs pc, lr + .size up_fullcontextrestore, . - up_fullcontextrestore + |