中断

rt_interrupt_leave 中为什么没有在退出中断时进行调度

发布于 2020-02-06 20:09:30 浏览：1074 订阅该版

5 个回答

rtt-fans 2020-02-07

这家伙很懒，什么也没写！

aozima 2020-02-07

调网络不抓包，调I2C等时序不上逻辑分析仪，就像电工不用万用表！多用整理的好的文字，比截图更省流量，还能在整理过程中思考。

rtt-fans 2020-02-08

这家伙很懒，什么也没写！

aozima 2020-02-08

调网络不抓包，调I2C等时序不上逻辑分析仪，就像电工不用万用表！多用整理的好的文字，比截图更省流量，还能在整理过程中思考。

rtt-fans 2020-02-08

这家伙很懒，什么也没写！

对于问题2：是在`IRQ_Handler`中断里进行的切换
```
IRQ_Handler PROC
    STMFD   SP!, {R0-R12,LR}
    BL      rt_interrupt_enter
    BL      rt_hw_trap_irq
    BL      rt_interrupt_leave

; If rt_thread_switch_interrupt_flag set,
    ; jump to rt_hw_context_switch_interrupt_do and don't return
    LDR     R0, =rt_thread_switch_interrupt_flag
    LDR     R1, [R0]
    CMP     R1, #1
    BEQ     rt_hw_context_switch_interrupt_do

LDMFD   SP!, {R0-R12,LR}
    SUBS    PC, LR, #4
    ENDP

;------ void rt_hw_context_switch_interrupt_do(rt_base_t flag) -----------------
rt_hw_context_switch_interrupt_do PROC
    MOV     R1,  #0                 ; Clear flag
    STR     R1,  [R0]               ; Save to flag variable

LDMFD   SP!, {R0-R12,LR}        ; Reload saved registers
    STMFD   SP, {R0-R2}             ; Save R0-R2
    SUB     R1,  SP, #4*3           ; Save old task's SP to R1
    SUB     R2,  LR, #4             ; Save old task's PC to R2

MRS     R0,  SPSR               ; Get CPSR of interrupt thread

MSR     CPSR_c, #MODE_SVC:OR:NOINT  ; Switch to SVC mode and no interrupt

STMFD   SP!, {R2}               ; Push old task's PC
    STMFD   SP!, {R3-R12,LR}        ; Push old task's LR,R12-R3
    LDMFD   R1, {R1-R3}
    STMFD   SP!, {R1-R3}            ; Push old task's R2-R0
    STMFD   SP!, {R0}               ; Push old task's CPSR

LDR     R4,  =rt_interrupt_from_thread
    LDR     R5,  [R4]               ; R5 = stack ptr in old tasks's TCB
    STR     SP,  [R5]               ; Store SP in preempted tasks's TCB

LDR     R6,  =rt_interrupt_to_thread
    LDR     R6,  [R6]               ; R6 = stack ptr in new tasks's TCB
    LDR     SP,  [R6]               ; Get new task's stack pointer

LDMFD   SP!, {R4}               ; Pop new task's SPSR
    MSR     SPSR_cxsf, R4

LDMFD   SP!, {R0-R12,LR,PC}^    ; pop new task's R0-R12,LR & PC SPSR to CPSR
    ENDP
```