/* * 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 "armv7.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 */ #if defined(__TI_VFP_SUPPORT__) || (defined (__VFP_FP__) && !defined(__SOFTFP__)) #ifndef RT_VFP_LAZY_STACKING { 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; } /*@}*/