diff options
Diffstat (limited to 'nuttx/arch/pjrc-8051/src/up_head.S')
| -rw-r--r-- | nuttx/arch/pjrc-8051/src/up_head.S | 153 |
1 files changed, 125 insertions, 28 deletions
diff --git a/nuttx/arch/pjrc-8051/src/up_head.S b/nuttx/arch/pjrc-8051/src/up_head.S index 662b6b18e..35acea2db 100644 --- a/nuttx/arch/pjrc-8051/src/up_head.S +++ b/nuttx/arch/pjrc-8051/src/up_head.S @@ -55,6 +55,7 @@ ************************************************************/ .globl _g_irqtos + .globl _g_irqcontext /************************************************************ * Public Functions @@ -167,18 +168,36 @@ _up_interrupt: clr psw push _bp - /* Mark that we are in an interrupt */ + /* Save the IRQ number in r3 */ + + mov r2, a + + /* Mark that we are in an interrupt and provide the top + * of stack pointer to the context switching logic. + */ mov dptr, #_g_irqtos + mov a, sp movx @dptr, a + /* Nullify the context pointer. If a context switch is + * needed, this will be set to the address of the context + * structure. + */ + + mov dptr,#_g_irqcontext + clr a + movx @dptr,a + inc dptr + movx @dptr,a + /* Now call void irq_dispatch(int irq, FAR void *context) * * First, create the first argument as (int)irqno */ - mov dpl, a - clr dph + mov dpl, r2 + mov dph, #0 /* Create the second argument (void *context) on the stack */ @@ -186,30 +205,120 @@ _up_interrupt: clr a push acc - /* Then dispatch the IRQ. On return, the stack is off by - * by two because the above two pushes, but we fix that by - * reloading sp from g_irqtos below. - */ + /* Then dispatch the IRQ. */ lcall _irq_dispatch + pop acc + pop acc - /* Get the stackpointer. This might be the stack pointer that - * we increment above or it might be the stack pointer of a - * new task if the a context switch happened during the - * interrupt handling. - */ + /* Indicate that we are no longer in an interrupt */ mov dptr, #_g_irqtos + clr a + movx @dptr, a + + /* Check if a context switch is pending */ + + mov dptr,#_g_irqcontext movx a, @dptr - mov sp, a + mov r2, a + inc dptr + movx a, @dptr + mov r3, a - /* Indicate that we are no longer in an interrupt */ + orl a, r2 + jz 00003$ + + /* A conext switch is pending Clear g_irqcontext */ + mov dpl, r2 + mov dph, r3 clr a movx @dptr, a + inc dptr + movx @dptr, a + +#ifdef CONFIG_INTERRUPT_FRAME_DUMP + mov dpl, r2 + mov dph, r3 + push ar2 + push ar3 + lcall _up_dumpframe + pop ar3 + pop ar2 +#endif + + /* Register usage in the following: + * + * R0 - Holds working the 8-bit IRAM pointer + * R1 - Not used + * R2-3 - Holds the working 16-bit XRAM pointer + * R4 - Holds the working byte count + * R5 - Holds the new stack pointer + * R6-7 - Not used + */ - /* Then return from the interrupt */ + /* Fetch r4 = context->nbytes */ + mov dpl, r2 + mov dph, r3 + movx a, @dptr + mov r4, a + + /* Save the new stack pointer in r5 */ + + add a, #(STACK_BASE-1) + mov r5, a + + /* Save r2-3 = &context->stack */ + + inc dptr + mov r2, dpl + mov r3, dph + + /* Set r0 = stack base address */ + + mov r0, #STACK_BASE + + /* Top of the copy loop */ +00001$: + dec r4 + jz 00002$ + + /* Fetch the next byte from context->stack */ + + mov dpl, r2 + mov dph, r3 + movx a,@dptr + + /* Increment the XRAM pointer */ + + inc dptr + mov r2, dpl + mov r3, dph + + /* Save the next byte into IRAM */ + + mov @r0, a + + /* Increment the IRAM pointer */ + + inc r0 + sjmp 00001$ + + /* Set the new stack pointer */ + +00002$: + mov sp, r5 + +#ifdef CONFIG_INTERRUPT_FRAME_DUMP + lcall _up_dumpstack +#endif + /* Then restore the context from the stack and return + * from the interrupt + */ + +00003$: pop _bp pop psw pop ar1 @@ -223,18 +332,6 @@ _up_interrupt: pop b pop dph pop dpl - - /* Restore the interrupt state per the stored IE value */ - + pop ie pop acc - jb acc.7, 00001$ - clr ie.7 - sjmp 00002$ - 00001$: - setb ie.7 - 00002$: - - /* Finally pop off the ACC, which was the first register saved. */ - - pop acc reti |