kopia lustrzana https://github.com/micropython/micropython
84 wiersze
2.2 KiB
C
84 wiersze
2.2 KiB
C
![]() |
#include <stdlib.h>
|
||
|
#include <stm32f4xx_hal.h>
|
||
|
|
||
|
#include "misc.h"
|
||
|
#include "mpconfig.h"
|
||
|
#include "qstr.h"
|
||
|
#include "obj.h"
|
||
|
#include "pendsv.h"
|
||
|
|
||
|
static void *pendsv_object = NULL;
|
||
|
|
||
|
void pendsv_init(void) {
|
||
|
// set PendSV interrupt at lowest priority
|
||
|
HAL_NVIC_SetPriority(PendSV_IRQn, 0xf, 0xf);
|
||
|
}
|
||
|
|
||
|
// call this function to raise a pending exception during an interrupt
|
||
|
// it will wait until all interrupts are finished then raise the given
|
||
|
// exception object using nlr_jump in the context of the top-level thread
|
||
|
void pendsv_nlr_jump(void *o) {
|
||
|
pendsv_object = o;
|
||
|
SCB->ICSR = SCB_ICSR_PENDSVSET_Msk;
|
||
|
}
|
||
|
|
||
|
// since we play tricks with the stack, the compiler must not generate a
|
||
|
// prelude for this function
|
||
|
void pendsv_isr_handler(void) __attribute__((naked));
|
||
|
|
||
|
void pendsv_isr_handler(void) {
|
||
|
// re-jig the stack so that when we return from this interrupt handler
|
||
|
// it returns instead to nlr_jump with argument pendsv_object
|
||
|
// note that stack has a different layout if DEBUG is enabled
|
||
|
//
|
||
|
// on entry to this (naked) function, stack has the following layout:
|
||
|
//
|
||
|
// stack layout with DEBUG disabled:
|
||
|
// sp[6]: pc
|
||
|
// sp[5]: ?
|
||
|
// sp[4]: ?
|
||
|
// sp[3]: ?
|
||
|
// sp[2]: ?
|
||
|
// sp[1]: ?
|
||
|
// sp[0]: r0
|
||
|
//
|
||
|
// stack layout with DEBUG enabled:
|
||
|
// sp[8]: pc
|
||
|
// sp[7]: lr
|
||
|
// sp[6]: ?
|
||
|
// sp[5]: ?
|
||
|
// sp[4]: ?
|
||
|
// sp[3]: ?
|
||
|
// sp[2]: r0
|
||
|
// sp[1]: 0xfffffff9
|
||
|
// sp[0]: ?
|
||
|
|
||
|
__asm volatile (
|
||
|
"ldr r0, pendsv_object_ptr\n"
|
||
|
"ldr r0, [r0]\n"
|
||
|
#if defined(PENDSV_DEBUG)
|
||
|
"str r0, [sp, #8]\n"
|
||
|
#else
|
||
|
"str r0, [sp, #0]\n"
|
||
|
#endif
|
||
|
"ldr r0, nlr_jump_ptr\n"
|
||
|
#if defined(PENDSV_DEBUG)
|
||
|
"str r0, [sp, #32]\n"
|
||
|
#else
|
||
|
"str r0, [sp, #24]\n"
|
||
|
#endif
|
||
|
"bx lr\n"
|
||
|
".align 2\n"
|
||
|
"pendsv_object_ptr: .word pendsv_object\n"
|
||
|
"nlr_jump_ptr: .word nlr_jump\n"
|
||
|
);
|
||
|
|
||
|
/*
|
||
|
uint32_t x[2] = {0x424242, 0xdeaddead};
|
||
|
printf("PendSV: %p\n", x);
|
||
|
for (uint32_t *p = (uint32_t*)(((uint32_t)x - 15) & 0xfffffff0), i = 64; i > 0; p += 4, i -= 4) {
|
||
|
printf(" %p: %08x %08x %08x %08x\n", p, (uint)p[0], (uint)p[1], (uint)p[2], (uint)p[3]);
|
||
|
}
|
||
|
*/
|
||
|
}
|