circuitpython/ports/qemu-arm/startup.c

85 lines
2.0 KiB
C
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#include <stdint.h>
#include <stdlib.h>
#include "uart.h"
extern uint32_t _estack, _sidata, _sdata, _edata, _sbss, _ebss;
__attribute__((naked)) void Reset_Handler(void) {
// set stack pointer
__asm volatile ("ldr r0, =_estack");
__asm volatile ("mov sp, r0");
// copy .data section from flash to RAM
for (uint32_t *src = &_sidata, *dest = &_sdata; dest < &_edata;) {
*dest++ = *src++;
}
// zero out .bss section
for (uint32_t *dest = &_sbss; dest < &_ebss;) {
*dest++ = 0;
}
// jump to board initialisation
void _start(void);
_start();
}
void Default_Handler(void) {
for (;;) {
}
}
const uint32_t isr_vector[] __attribute__((section(".isr_vector"))) = {
(uint32_t)&_estack,
(uint32_t)&Reset_Handler,
(uint32_t)&Default_Handler, // NMI_Handler
(uint32_t)&Default_Handler, // HardFault_Handler
(uint32_t)&Default_Handler, // MemManage_Handler
(uint32_t)&Default_Handler, // BusFault_Handler
(uint32_t)&Default_Handler, // UsageFault_Handler
0,
0,
0,
0,
(uint32_t)&Default_Handler, // SVC_Handler
(uint32_t)&Default_Handler, // DebugMon_Handler
0,
(uint32_t)&Default_Handler, // PendSV_Handler
(uint32_t)&Default_Handler, // SysTick_Handler
};
void _start(void) {
// Enable the UART
uart_init();
// Now that we have a basic system up and running we can call main
extern int main();
main(0, 0);
// Finished
exit(0);
}
__attribute__((naked)) void exit(int status) {
// Force qemu to exit using ARM Semihosting
__asm volatile (
"mov r1, r0\n"
"cmp r1, #0\n"
"bne .notclean\n"
"ldr r1, =0x20026\n" // ADP_Stopped_ApplicationExit, a clean exit
".notclean:\n"
"movs r0, #0x18\n" // SYS_EXIT
"bkpt 0xab\n"
);
for (;;) {
}
}
// The following are needed for tinytest
#include <stdio.h>
int setvbuf(FILE *stream, char *buf, int mode, size_t size) {
return 0;
}
struct _reent *_impure_ptr;