diff options
Diffstat (limited to 'VexRiscvSocSoftware/projects/murax/wip/src')
-rw-r--r-- | VexRiscvSocSoftware/projects/murax/wip/src/crt.c | 64 | ||||
-rwxr-xr-x | VexRiscvSocSoftware/projects/murax/wip/src/main.c | 58 |
2 files changed, 122 insertions, 0 deletions
diff --git a/VexRiscvSocSoftware/projects/murax/wip/src/crt.c b/VexRiscvSocSoftware/projects/murax/wip/src/crt.c new file mode 100644 index 0000000..70e6c06 --- /dev/null +++ b/VexRiscvSocSoftware/projects/murax/wip/src/crt.c @@ -0,0 +1,64 @@ +/* +Created by: roman3017 +Inspired by: https://jacobmossberg.se/posts/2018/08/11/run-c-program-bare-metal-on-arm-cortex-m3.html +*/ + +extern unsigned int __global_pointer$; +extern unsigned int _stack_start; +extern unsigned int _bss_start; +extern unsigned int _bss_end; +extern unsigned int _ctors_start; +extern unsigned int _ctors_end; + +void crtStart(); +void irqCallback(); +void main(); + +static void trapEntry(); +static void bssInit(); +static void ctorsInit(); + +unsigned int * initVectors[2] __attribute__ ((section("vectors"))) = { + (unsigned int *) crtStart, // code entry + (unsigned int *) trapEntry, // trap entry +}; + +void crtStart() +{ + /* Initialize sp and gp registers */ + asm volatile ( + "la gp, %0\n\t" + "la sp, %1\n\t" + :: "i"(&__global_pointer$), "i"(&_stack_start) + ); + + bssInit(); + ctorsInit(); + main(); + asm volatile("j ."); +} + +static void trapEntry() +{ + irqCallback(); +} + +static void bssInit() +{ + unsigned int * bss_start_p = &_bss_start; + unsigned int * bss_end_p = &_bss_end; + while(bss_start_p != bss_end_p) { + *bss_start_p++ = 0; + } +} + +static void ctorsInit() +{ + unsigned int * ctors_start_p = &_ctors_start; + unsigned int * ctors_end_p = &_ctors_end; + void(*ctor)(); + while(ctors_start_p != ctors_end_p) { + ctor = (void *)*ctors_start_p++; + ctor(); + } +} diff --git a/VexRiscvSocSoftware/projects/murax/wip/src/main.c b/VexRiscvSocSoftware/projects/murax/wip/src/main.c new file mode 100755 index 0000000..2d92b76 --- /dev/null +++ b/VexRiscvSocSoftware/projects/murax/wip/src/main.c @@ -0,0 +1,58 @@ +#include <stdint.h> +#include <murax.h> + +/* bss section */ +uint32_t a, b, c; + +/* ctor section */ +void __attribute__ ((constructor)) defaultConstructor() +{ + c += 3; +} + +/* text section */ +void main() +{ + uint32_t result; + + interruptCtrl_init(TIMER_INTERRUPT); + prescaler_init(TIMER_PRESCALER); + timer_init(TIMER_A); + + TIMER_PRESCALER->LIMIT = 12000-1; //1 ms rate + + TIMER_A->LIMIT = 1000-1; //1 second rate + TIMER_A->CLEARS_TICKS = 0x00010002; + + TIMER_INTERRUPT->PENDINGS = 0xF; + TIMER_INTERRUPT->MASKS = 0x1; + + GPIO_A->OUTPUT_ENABLE = 0x000000FF; + GPIO_A->OUTPUT = 0x00000000; + + UART->STATUS = 2; //Enable RX interrupts + UART->DATA = 'A'; + + result = 0; + a = 1, b = 2; + while(1){ + result += a; + result += b + c; + for(uint32_t idx = 0;idx < 50000;idx++) asm volatile(""); + GPIO_A->OUTPUT = (GPIO_A->OUTPUT & ~0x3F) | ((GPIO_A->OUTPUT + 1) & 0x3F); //Counter on LED[5:0] + } +} + +void irqCallback() +{ + if(TIMER_INTERRUPT->PENDINGS & 1){ //Timer A interrupt + GPIO_A->OUTPUT ^= 0x80; //Toogle led 7 + TIMER_INTERRUPT->PENDINGS = 1; + } + while(UART->STATUS & (1 << 9)){ //UART RX interrupt + UART->DATA = (UART->DATA) & 0xFF; + } +} + + + |