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Diffstat (limited to 'nuttx/arch/arm/src/common/up_createstack.c')
| -rw-r--r-- | nuttx/arch/arm/src/common/up_createstack.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/common/up_createstack.c b/nuttx/arch/arm/src/common/up_createstack.c new file mode 100644 index 000000000..3d6dfef45 --- /dev/null +++ b/nuttx/arch/arm/src/common/up_createstack.c @@ -0,0 +1,197 @@ +/**************************************************************************** + * arch/arm/src/common/up_createstack.c + * + * Copyright (C) 2007-2012 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * 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 NuttX 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 <stdint.h> +#include <sched.h> +#include <debug.h> + +#include <nuttx/kmalloc.h> +#include <nuttx/arch.h> +#include <arch/board/board.h> + +#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 + ****************************************************************************/ + +/**************************************************************************** + * Name: memset32 + * + * On most larger then 8 bit archs this will need to be word aligned so + * so maybe some checks should be put in place? + * + ****************************************************************************/ + +#if defined(CONFIG_DEBUG) && defined(CONFIG_DEBUG_STACK) +static void *memset32(void *s, uint32_t c, size_t n) +{ + uint32_t *p = (uint32_t *)s; + while (n-- > 0) *p++ = c; + return s; +} +#endif + +/**************************************************************************** + * 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 stack_alloc_ptr 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. + ****************************************************************************/ + +int up_create_stack(_TCB *tcb, size_t 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) + { +#ifdef CONFIG_DEBUG + tcb->stack_alloc_ptr = (uint32_t*)kzalloc(stack_size); +#else + 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; + + /* 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; 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. + */ + + size_of_stack = top_of_stack - (uint32_t)tcb->stack_alloc_ptr + 4; + + /* 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); +#endif + + up_ledon(LED_STACKCREATED); + return OK; + } + + return ERROR; +} + |