rt-thread-official/libcpu/arm/am335x/stack.c

65 lines
2.0 KiB
C

/*
* Copyright (c) 2006-2021, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2011-09-23 Bernard the first version
* 2011-10-05 Bernard add thumb mode
*/
#include <rtthread.h>
#include "am33xx.h"
/**
* @addtogroup AM33xx
*/
/*@{*/
/**
* This function will initialize thread stack
*
* @param tentry the entry of thread
* @param parameter the parameter of entry
* @param stack_addr the beginning stack address
* @param texit the function will be called when thread exit
*
* @return stack address
*/
rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
rt_uint8_t *stack_addr, void *texit)
{
rt_uint32_t *stk;
stack_addr += sizeof(rt_uint32_t);
stack_addr = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 8);
stk = (rt_uint32_t *)stack_addr;
*(--stk) = (rt_uint32_t)tentry; /* entry point */
*(--stk) = (rt_uint32_t)texit; /* lr */
*(--stk) = 0xdeadbeef; /* r12 */
*(--stk) = 0xdeadbeef; /* r11 */
*(--stk) = 0xdeadbeef; /* r10 */
*(--stk) = 0xdeadbeef; /* r9 */
*(--stk) = 0xdeadbeef; /* r8 */
*(--stk) = 0xdeadbeef; /* r7 */
*(--stk) = 0xdeadbeef; /* r6 */
*(--stk) = 0xdeadbeef; /* r5 */
*(--stk) = 0xdeadbeef; /* r4 */
*(--stk) = 0xdeadbeef; /* r3 */
*(--stk) = 0xdeadbeef; /* r2 */
*(--stk) = 0xdeadbeef; /* r1 */
*(--stk) = (rt_uint32_t)parameter; /* r0 : argument */
/* cpsr */
if ((rt_uint32_t)tentry & 0x01)
*(--stk) = SVCMODE | 0x20; /* thumb mode */
else
*(--stk) = SVCMODE; /* arm mode */
/* return task's current stack address */
return (rt_uint8_t *)stk;
}
/*@}*/