rt-thread/libcpu/arm/cortex-r4/stack.c

86 lines
2.1 KiB
C

/*
* File : stack.c
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2006, RT-Thread Development Team
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://openlab.rt-thread.com/license/LICENSE
*
* Change Logs:
* Date Author Notes
* 2008-12-11 XuXinming first version
* 2013-05-24 Grissiom port to RM48x50
*/
#include <rtthread.h>
#include "RM48x50.h"
/**
* @addtogroup RM48x50
*/
/*@{*/
/**
* 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)
{
unsigned long *stk;
stk = (unsigned long*)stack_addr;
*( stk) = (unsigned long) tentry; /* entry point */
*(--stk) = (unsigned long) texit; /* lr */
*(--stk) = 0; /* r12 */
*(--stk) = 0; /* r11 */
*(--stk) = 0; /* r10 */
*(--stk) = 0; /* r9 */
*(--stk) = 0; /* r8 */
*(--stk) = 0; /* r7 */
*(--stk) = 0; /* r6 */
*(--stk) = 0; /* r5 */
*(--stk) = 0; /* r4 */
*(--stk) = 0; /* r3 */
*(--stk) = 0; /* r2 */
*(--stk) = 0; /* r1 */
*(--stk) = (unsigned long)parameter; /* r0 : argument */
/* cpsr */
if ((rt_uint32_t)tentry & 0x01)
*(--stk) = SVCMODE | 0x20; /* thumb mode */
else
*(--stk) = SVCMODE; /* arm mode */
#ifdef __TI_VFP_SUPPORT__
#ifndef RT_VFP_LAZY_STACKING
{
#define VFP_DATA_NR 32
int i;
for (i = 0; i < VFP_DATA_NR; i++)
{
*(--stk) = 0;
}
/* FPSCR TODO: do we need to set the values other than 0? */
*(--stk) = 0;
/* FPEXC. Enable the FVP if no lazy stacking. */
*(--stk) = 0x40000000;
}
#else
/* FPEXC. Disable the FVP by default. */
*(--stk) = 0x00000000;
#endif
#endif
/* return task's current stack address */
return (rt_uint8_t *)stk;
}
/*@}*/