/**************************************************************************** * arch/arm/src/common/up_createstack.c * * Copyright (C) 2007-2013 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 by this function: * * - 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. * - ttype: The thread type. This may be one of following (defined in * include/nuttx/sched.h): * * TCB_FLAG_TTYPE_TASK Normal user task * TCB_FLAG_TTYPE_PTHREAD User pthread * TCB_FLAG_TTYPE_KERNEL Kernel thread * * This thread type is normally available in the flags field of the TCB, * however, there are certain contexts where the TCB may not be fully * initialized when up_create_stack is called. * * If CONFIG_NUTTX_KERNEL is defined, then this thread type may affect * how the stack is allocated. For example, kernel thread stacks should * be allocated from protected kernel memory. Stacks for user tasks and * threads must come from memory that is accessible to user code. * ****************************************************************************/ int up_create_stack(FAR struct tcb_s *tcb, size_t stack_size, uint8_t ttype) { /* Is there already a stack allocated of a different size? Because of * alignment issues, stack_size might erroneously appear to be of a * different size. Fortunately, this is not a critical operation. */ if (tcb->stack_alloc_ptr && tcb->adj_stack_size != stack_size) { /* Yes.. Release the old stack */ up_release_stack(tcb, ttype); } /* Do we need to allocate a new stack? */ if (!tcb->stack_alloc_ptr) { /* Allocate the stack. If DEBUG is enabled (but not stack debug), * then create a zeroed stack to make stack dumps easier to trace. */ #if defined(CONFIG_NUTTX_KERNEL) && defined(CONFIG_MM_KERNEL_HEAP) /* Use the kernel allocator if this is a kernel thread */ if (ttype == TCB_FLAG_TTYPE_KERNEL) { #if defined(CONFIG_DEBUG) && !defined(CONFIG_DEBUG_STACK) tcb->stack_alloc_ptr = (uint32_t *)kzalloc(stack_size); #else tcb->stack_alloc_ptr = (uint32_t *)kmalloc(stack_size); #endif } else #endif { /* Use the user-space allocator if this is a task or pthread */ #if defined(CONFIG_DEBUG) && !defined(CONFIG_DEBUG_STACK) tcb->stack_alloc_ptr = (uint32_t *)kuzalloc(stack_size); #else tcb->stack_alloc_ptr = (uint32_t *)kumalloc(stack_size); #endif } #ifdef CONFIG_DEBUG /* Was the allocation successful? */ if (!tcb->stack_alloc_ptr) { sdbg("ERROR: Failed to allocate stack, size %d\n", stack_size); } #endif } /* Did we successfully allocate a 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 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 struct tcb_s */ 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; }