5 rk3399移植遇到的问题

发布于 2021-09-07 21:36:10 浏览：1881 订阅该版

目前只有main线程和idle线程，main线程调用rt_thread_delay函数导致系统卡死
```C
int main(int argc, char** argv)
{
    rt_tick_t current_tick;
    rt_kprintf("Hi, this is RT-Thread!!\n");

while (1)
    {   
        current_tick = rt_tick_get();
        rt_kprintf("%d\r\n", current_tick);
        rt_thread_delay(100);
    }
    return 0;
}
```
最终确认在rt_hw_context_switch函数卡死
```C
rt_kprintf("rt_hw_context_switch start!\r\n");

rt_hw_context_switch((rt_ubase_t)&from_thread->sp,
                            (rt_ubase_t)&to_thread->sp);

rt_kprintf("rt_hw_context_switch end!\r\n");
```
这个函数实现如下
```C
.globl rt_hw_context_switch
rt_hw_context_switch:

MOV		X8,X0
    MOV		X9,X1

//SAVE_CONTEXT_T

/* Switch to use the EL0 stack pointer. */
    MSR 	SPSEL, #0
    //MSR 	SPSEL, #1

/* Save the entire context. */
    STP 	X0, X1, [SP, #-0x10]!
    STP 	X2, X3, [SP, #-0x10]!
    STP 	X4, X5, [SP, #-0x10]!
    STP 	X6, X7, [SP, #-0x10]!
    STP 	X8, X9, [SP, #-0x10]!
    STP 	X10, X11, [SP, #-0x10]!
    STP 	X12, X13, [SP, #-0x10]!
    STP 	X14, X15, [SP, #-0x10]!
    STP 	X16, X17, [SP, #-0x10]!
    STP 	X18, X19, [SP, #-0x10]!
    STP 	X20, X21, [SP, #-0x10]!
    STP 	X22, X23, [SP, #-0x10]!
    STP 	X24, X25, [SP, #-0x10]!
    STP 	X26, X27, [SP, #-0x10]!
    STP 	X28, X29, [SP, #-0x10]!
    STP 	X30, XZR, [SP, #-0x10]!

MRS		X0, CurrentEL
    CMP		X0, 0xc
    B.EQ	3f
    CMP		X0, 0x8
    B.EQ	2f
    CMP		X0, 0x4
    B.EQ	1f
    B 		.
3:
    MRS		X3, SPSR_EL3
    MOV		X2, X30
    B		0f
2:
    MRS		X3, SPSR_EL2
    MOV		X2, X30
    B		0f
1:
    MRS		X3, SPSR_EL1
    MOV		X2, X30
    B		0f
0:

STP 	X2, X3, [SP, #-0x10]!

MOV 	X0, SP   /* Move SP into X0 for saving. */

/* Switch to use the ELx stack pointer. */
    MSR 	SPSEL, #1

STR		X0, [X8]            // store sp in preempted tasks TCB
    LDR		X0, [X9]            // get new task stack pointer
    
   // RESTORE_CONTEXT

/* Switch to use the EL0 stack pointer. */
    MSR 	SPSEL, #0
    //MSR 	SPSEL, #1

/* Set the SP to point to the stack of the task being restored. */
    MOV		SP, X0

LDP 	X2, X3, [SP], #0x10  /* SPSR and ELR. */

MRS		X0, CurrentEL
    CMP		X0, 0xc
    B.EQ	3f
    CMP		X0, 0x8
    B.EQ	2f
    CMP		X0, 0x4
    B.EQ	1f
    B 		.
3:
    MSR		SPSR_EL3, X3
    MSR		ELR_EL3, X2
    B		0f
2:
    MSR		SPSR_EL2, X3
    MSR		ELR_EL2, X2
    B		0f
1:
    MSR		SPSR_EL1, X3
    MSR		ELR_EL1, X2
    B		0f
0:

LDP 	X30, XZR, [SP], #0x10
    LDP 	X28, X29, [SP], #0x10
    LDP 	X26, X27, [SP], #0x10
    LDP 	X24, X25, [SP], #0x10
    LDP 	X22, X23, [SP], #0x10
    LDP 	X20, X21, [SP], #0x10
    LDP 	X18, X19, [SP], #0x10
    LDP 	X16, X17, [SP], #0x10
    LDP 	X14, X15, [SP], #0x10
    LDP 	X12, X13, [SP], #0x10
    LDP 	X10, X11, [SP], #0x10
    LDP 	X8, X9, [SP], #0x10
    LDP 	X6, X7, [SP], #0x10
    LDP 	X4, X5, [SP], #0x10
    LDP 	X2, X3, [SP], #0x10
    LDP 	X0, X1, [SP], #0x10

/* Switch to use the ELx stack pointer.  _RB_ Might not be required. */
    MSR 	SPSEL, #1

ERET
```
感觉没啥大问题，实在是不会改了，有大神指导一下嘛