/**************************************************************************** * arch/arm/src/common/up_createstack.c * * Copyright (C) 2007-2012 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include #include #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; }