1 files changed, 126 insertions, 0 deletions
diff --git a/nuttx/arch/c5471/src/up_createstack.c b/nuttx/arch/c5471/src/up_createstack.c
new file mode 100644
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+++ b/nuttx/arch/c5471/src/up_createstack.c
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+/************************************************************
+ * up_createstack.c
+ *
+ *   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/config.h>
+#include <sys/types.h>
+#include <sched.h>
+#include <debug.h>
+#include <nuttx/kmalloc.h>
+#include <nuttx/arch.h>
+#include "up_internal.h"
+
+/************************************************************
+ * Private Types
+ ************************************************************/
+
+/************************************************************
+ * Private Function Prototypes
+ ************************************************************/
+
+/************************************************************
+ * Global Functions
+ ************************************************************/
+
+/************************************************************
+ * Name: up_create_stack
+ *
+ * Description:
+ *   Allocate a stack for a new thread and setup
+ *   up stack-related information in the TCB.
+ *
+ *   The following TCB fields must be initialized:
+ *   adj_stack_size: Stack size after adjustment for hardware,
+ *     processor, etc.  This value is retained only for debug
+ *     purposes.
+ *   stack_alloc_ptr: Pointer to allocated stack
+ *   adj_stack_ptr: Adjusted StatckAllocPtr for HW.  The
+ *     initial value of the stack pointer.
+ *
+ * Inputs:
+ *   tcb: The TCB of new task
+ *   stack_size:  The requested stack size.  At least this much
+ *     must be allocated.
+ ************************************************************/
+
+STATUS up_create_stack(_TCB *tcb, uint32 stack_size)
+{
+  if (tcb->stack_alloc_ptr &&
+      tcb->adj_stack_size != stack_size)
+    {
+      sched_free(tcb->stack_alloc_ptr);
+      tcb->stack_alloc_ptr = NULL;
+    }
+
+   if (!tcb->stack_alloc_ptr)
+     {
+       tcb->stack_alloc_ptr = (uint32 *)kzmalloc(stack_size);
+     }
+
+   if (tcb->stack_alloc_ptr)
+     {
+       uint32 top_of_stack;
+       uint32 size_of_stack;
+
+       /* The Arm7Tdmi uses a push-down stack:  the stack grows
+	* toward loweraddresses in memory.  The stack pointer
+	* register, points to the lowest, valid work address
+	* (the "top" of the stack).  Items on the stack are
+	* referenced as positive word offsets from sp.
+	*/
+
+       top_of_stack = (uint32)tcb->stack_alloc_ptr + stack_size - 4;
+
+       /* The Arm7Tdmi stack must be aligned at word (4 byte)
+	* boundaries. If necessary top_of_stack must be rounded
+	* down to the next boundary
+	*/
+
+       top_of_stack &= ~3;
+       size_of_stack = top_of_stack - (uint32)tcb->stack_alloc_ptr + 4;
+
+       /* Save the adjusted stack values in the _TCB */
+
+       tcb->adj_stack_size = top_of_stack;
+       tcb->adj_stack_size = size_of_stack;
+
+       return OK;
+     }
+
+   return ERROR;
+}