线程

线程创建

初始化上下文信息
将栈初始化为 #号


rt_uint8_t *rt_hw_stack_init(void       *tentry,

                             void       *parameter,

                             rt_uint8_t *stack_addr,

                             void       *texit)

{

    struct stack_frame *stack_frame;

    rt_uint8_t         *stk;

    unsignedlong       i;


    stk  = stack_addr + sizeof(rt_uint32_t);

    stk  = (rt_uint8_t *)RT_ALIGN_DOWN((rt_uint32_t)stk, 8);

    stk -= sizeof(struct stack_frame);


    stack_frame = (struct stack_frame *)stk;


    /* init all register */

    for (i = 0; i < sizeof(struct stack_frame) / sizeof(rt_uint32_t); i ++)

    {

        ((rt_uint32_t *)stack_frame)[i] = 0xdeadbeef;

    }


    stack_frame->exception_stack_frame.r0  = (unsignedlong)parameter; /* r0 : argument */

    stack_frame->exception_stack_frame.r1  = 0;                        /* r1 */

    stack_frame->exception_stack_frame.r2  = 0;                        /* r2 */

    stack_frame->exception_stack_frame.r3  = 0;                        /* r3 */

    stack_frame->exception_stack_frame.r12 = 0;                        /* r12 */

    stack_frame->exception_stack_frame.lr  = (unsignedlong)texit;     /* lr */

    stack_frame->exception_stack_frame.pc  = (unsignedlong)tentry;    /* entry point, pc */

    stack_frame->exception_stack_frame.psr = 0x01000000L;              /* PSR */


#if USE_FPU

    stack_frame->flag =0;

#endif /* USE_FPU */


    /* return task's current stack address */

    return stk;

}