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MIPS stack alignment fix for floating point from Helmut

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5681 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo
2013-02-27 16:31:03 +00:00
parent 753dfdba14
commit 75a1f693d1
1 changed files with 30 additions and 10 deletions
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arch/mips/src/common/up_createstack.c
+30 -10
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@@ -1,7 +1,7 @@
/**************************************************************************** /****************************************************************************
* arch/mips/src/common/up_createstack.c * arch/mips/src/common/up_createstack.c
* *
* Copyright (C) 2011 Gregory Nutt. All rights reserved. * Copyright (C) 2011, 2013 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org> * Author: Gregory Nutt <gnutt@nuttx.org>
* *
* Redistribution and use in source and binary forms, with or without * Redistribution and use in source and binary forms, with or without
@@ -51,6 +51,26 @@
#include "up_arch.h" #include "up_arch.h"
#include "up_internal.h" #include "up_internal.h"
/****************************************************************************
* Pre-processor Macros
****************************************************************************/
/* MIPS requires at least a 4-byte stack alignment. For floating point use,
* however, the stack must be aligned to 8-byte addresses.
*/
#ifdef CONFIG_LIBC_FLOATINGPOINT
# define CONFIG_STACK_ALIGNMENT 8
#else
# define CONFIG_STACK_ALIGNMENT 4
#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 * Private Types
****************************************************************************/ ****************************************************************************/
@@ -107,21 +127,21 @@ int up_create_stack(struct tcb_s *tcb, size_t stack_size)
size_t top_of_stack; size_t top_of_stack;
size_t size_of_stack; size_t size_of_stack;
/* MIPS uses a push-down stack: the stack grows /* MIPS uses a push-down stack: the stack grows toward lower
* toward loweraddresses in memory. The stack pointer * addresses in memory. The stack pointer register points to the
* register, points to the lowest, valid work address * lowest, valid working address (the "top" of the stack). Items on
* (the "top" of the stack). Items on the stack are * the stack are referenced as positive word offsets from sp.
* 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 MIPS stack must be aligned at word (4 byte) /* The MIPS stack must be aligned at word (4 byte) boundaries; for
* boundaries. If necessary top_of_stack must be rounded * floating point use, the stack must be aligned to 8-byte addresses.
* down to the next boundary * If necessary top_of_stack must be rounded down to the next
* boundary to meet these alignment requirements.
*/ */
top_of_stack &= ~3; top_of_stack = STACK_ALIGN_DOWN(top_of_stack);
size_of_stack = top_of_stack - (uint32_t)tcb->stack_alloc_ptr + 4; size_of_stack = top_of_stack - (uint32_t)tcb->stack_alloc_ptr + 4;
/* Save the adjusted stack values in the struct tcb_s */ /* Save the adjusted stack values in the struct tcb_s */