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Fix stack alignment for EABI floating point

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4089 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2011-11-11 14:06:10 +00:00
parent f7642cf1cd
commit 7ea157b328
5 changed files with 121 additions and 43 deletions
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3
ChangeLog
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@ -2194,4 +2194,7 @@
support a file system (such as NXFFS). (Contributed by Hal Glenn).
* include/nuttx/rgbcolors.h: More fixes to RGB color conversion
macros.
* arch/arm/src/common/up_createstack.c and up_usestack.c: For ARM EABI
the stack must be aligned to 8-byte boundaries. This is necessary for
passing aligned floating point values under EABI.

7
Documentation/NuttxPortingGuide.html
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@ -5114,7 +5114,12 @@ build
some functions into RAM, either for better performance or for errata workarounds.
</li>
<li>
<code>CONFIG_STACK_POINTER</code>: The initial stack pointer
<code>CONFIG_STACK_POINTER</code>: The initial stack pointer (may not be supported
in all architectures).
</li>
<li>
<code>CONFIG_STACK_ALIGNMENT</code>: Set if the your application has specific
stack alignment requirements (may not be supported in all architectures).
</li>
<li>
<code>CONFIG_IDLETHREAD_STACKSIZE</code>: The size of the initial stack.

99
arch/arm/src/common/up_createstack.c
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@ -51,6 +51,33 @@
#include "up_arch.h"
#include "up_internal.h"
/****************************************************************************
* Pre-processor Macros
****************************************************************************/
/* ARM requires at least a 4-byte stack alignment. For use with EABI and
* floating point, the stack must be aligned to 8-byte addresses.
*/
#ifndef CONFIG_STACK_ALIGNMENT
/* The symbol __ARM_EABI__ is defined by GCC if EABI is being used. If you
* are not using GCC, make sure that CONFIG_STACK_ALIGNMENT is set correctly!
*/
# ifdef __ARM_EABI__
# define CONFIG_STACK_ALIGNMENT 8
# else
# define CONFIG_STACK_ALIGNMENT 4
# endif
#endif
/* Stack alignment macros */
#define STACK_ALIGN_MASK (CONFIG_STACK_ALIGNMENT-1)
#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
#define STACK_ALIGN_UP(a) (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
/****************************************************************************
* Private Types
****************************************************************************/
@ -110,54 +137,60 @@ int up_create_stack(_TCB *tcb, size_t stack_size)
tcb->stack_alloc_ptr = NULL;
}
if (!tcb->stack_alloc_ptr)
{
if (!tcb->stack_alloc_ptr)
{
#ifdef CONFIG_DEBUG
tcb->stack_alloc_ptr = (uint32_t*)kzalloc(stack_size);
tcb->stack_alloc_ptr = (uint32_t*)kzalloc(stack_size);
#else
tcb->stack_alloc_ptr = (uint32_t*)kmalloc(stack_size);
tcb->stack_alloc_ptr = (uint32_t*)kmalloc(stack_size);
#endif
}
}
if (tcb->stack_alloc_ptr)
{
size_t top_of_stack;
size_t size_of_stack;
if (tcb->stack_alloc_ptr)
{
size_t top_of_stack;
size_t size_of_stack;
/* The ARM 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.
*/
/* The ARM uses a push-down stack: the stack grows toward lower
* addresses 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_t)tcb->stack_alloc_ptr + stack_size - 4;
top_of_stack = (uint32_t)tcb->stack_alloc_ptr + stack_size - 4;
/* The ARM stack must be aligned at word (4 byte)
* boundaries. If necessary top_of_stack must be rounded
* down to the next boundary
*/
/* The ARM stack must be aligned; 4 byte alignment for OABI and
* 8-byte alignment for EABI. If necessary top_of_stack must be
* rounded down to the next boundary
*/
top_of_stack &= ~3;
size_of_stack = top_of_stack - (uint32_t)tcb->stack_alloc_ptr + 4;
top_of_stack = STACK_ALIGN_DOWN(top_of_stack);
/* Save the adjusted stack values in the _TCB */
/* The size of the stack in bytes is then the difference between
* the top and the bottom of the stack (+4 because if the top
* is the same as the bottom, then the size is one 32-bit element).
* The size need not be aligned.
*/
tcb->adj_stack_ptr = (uint32_t*)top_of_stack;
tcb->adj_stack_size = size_of_stack;
size_of_stack = top_of_stack - (uint32_t)tcb->stack_alloc_ptr + 4;
/* If stack debug is enabled, then fill the stack with a
* recognizable value that we can use later to test for high
* water marks.
*/
/* Save the adjusted stack values in the _TCB */
tcb->adj_stack_ptr = (uint32_t*)top_of_stack;
tcb->adj_stack_size = size_of_stack;
/* If stack debug is enabled, then fill the stack with a
* recognizable value that we can use later to test for high
* water marks.
*/
#if defined(CONFIG_DEBUG) && defined(CONFIG_DEBUG_STACK)
memset32(tcb->stack_alloc_ptr, 0xDEADBEEF, tcb->adj_stack_size/4);
memset32(tcb->stack_alloc_ptr, 0xDEADBEEF, tcb->adj_stack_size/4);
#endif
up_ledon(LED_STACKCREATED);
return OK;
}
up_ledon(LED_STACKCREATED);
return OK;
}
return ERROR;
}

49
arch/arm/src/common/up_usestack.c
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@ -49,6 +49,33 @@
#include "up_internal.h"
/****************************************************************************
* Pre-processor Macros
****************************************************************************/
/* ARM requires at least a 4-byte stack alignment. For use with EABI and
* floating point, the stack must be aligned to 8-byte addresses.
*/
#ifndef CONFIG_STACK_ALIGNMENT
/* The symbol __ARM_EABI__ is defined by GCC if EABI is being used. If you
* are not using GCC, make sure that CONFIG_STACK_ALIGNMENT is set correctly!
*/
# ifdef __ARM_EABI__
# define CONFIG_STACK_ALIGNMENT 8
# else
# define CONFIG_STACK_ALIGNMENT 4
# endif
#endif
/* Stack alignment macros */
#define STACK_ALIGN_MASK (CONFIG_STACK_ALIGNMENT-1)
#define STACK_ALIGN_DOWN(a) ((a) & ~STACK_ALIGN_MASK)
#define STACK_ALIGN_UP(a) (((a) + STACK_ALIGN_MASK) & ~STACK_ALIGN_MASK)
/****************************************************************************
* Private Types
****************************************************************************/
@ -96,21 +123,27 @@ int up_use_stack(_TCB *tcb, void *stack, size_t stack_size)
tcb->stack_alloc_ptr = stack;
/* The ARM 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
/* The ARM uses a push-down stack: the stack grows toward lower addresses
* 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_t)tcb->stack_alloc_ptr + stack_size - 4;
/* The ARM stack must be aligned at word (4 byte)
* boundaries. If necessary top_of_stack must be rounded
* down to the next boundary
/* The ARM stack must be aligned; 4 byte alignment for OABI and 8-byte
* alignment for EABI. If necessary top_of_stack must be rounded down
* to the next boundary
*/
top_of_stack = STACK_ALIGN_DOWN(top_of_stack);
/* The size of the stack in bytes is then the difference between
* the top and the bottom of the stack (+4 because if the top
* is the same as the bottom, then the size is one 32-bit element).
* The size need not be aligned.
*/
top_of_stack &= ~3;
size_of_stack = top_of_stack - (uint32_t)tcb->stack_alloc_ptr + 4;
/* Save the adjusted stack values in the _TCB */

6
configs/README.txt
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@ -1148,7 +1148,11 @@ defconfig -- This is a configuration file similar to the Linux
but copy themselves entirely into RAM for better performance.
CONFIG_BOOT_RAMFUNCS - Other configurations may copy just some functions
into RAM, either for better performance or for errata workarounds.
CONFIG_STACK_POINTER - The initial stack pointer
CONFIG_STACK_POINTER - The initial stack pointer (may not be supported
in all architectures).
CONFIG_STACK_ALIGNMENT - Set if the your application has specific
stack alignment requirements (may not be supported
in all architectures).
CONFIG_IDLETHREAD_STACKSIZE - The size of the initial stack.
This is the thread that (1) performs the inital boot of the system up
to the point where user_start() is spawned, and (2) there after is the