MNRS-BM-BSP/env/ehrenberg/init.c
2024-10-01 10:56:40 +02:00

139 lines
2.7 KiB
C

#include <stdint.h>
#include <stdio.h>
#include <unistd.h>
#include "platform.h"
#include "encoding.h"
extern int main(int argc, char** argv);
extern void trap_entry(void);
#define IRQ_M_SOFT 3
#define IRQ_M_TIMER 7
#define IRQ_M_EXT 11
#define NUM_INTERRUPTS 16
#define MTIMER_NEXT_TICK_INC 1000
void handle_m_ext_interrupt(void);
void handle_m_time_interrupt(void);
uint32_t handle_trap(uint32_t mcause, uint32_t mepc, uint32_t sp);
void default_handler(void);
void _init(void);
typedef void (*my_interrupt_function_ptr_t) (void);
my_interrupt_function_ptr_t localISR[NUM_INTERRUPTS] __attribute__((aligned(64)));
static unsigned long mtime_lo(void)
{
unsigned long ret;
__asm volatile("rdtime %0":"=r"(ret));
return ret;
}
#if __riscv_xlen==32
static uint32_t mtime_hi(void)
{
unsigned long ret;
__asm volatile("rdtimeh %0":"=r"(ret));
return ret;
}
uint64_t get_timer_value(void)
{
while (1) {
uint32_t hi = mtime_hi();
uint32_t lo = mtime_lo();
if (hi == mtime_hi())
return ((uint64_t)hi << 32) | lo;
}
}
#elif __riscv_xlen==64
uint64_t get_timer_value()
{
return mtime_lo();
}
#endif
unsigned long get_timer_freq()
{
return 32768;
}
unsigned long get_cpu_freq()
{
return 100000000;
}
void init_pll(void){
//TODO: implement initialization
}
static void uart_init(size_t baud_rate)
{
//TODO: implement initialization
}
void __attribute__((weak)) handle_m_ext_interrupt(){
}
void __attribute__((weak)) handle_m_time_interrupt(){
uint64_t time = get_aclint_mtime(aclint);
time+=MTIMER_NEXT_TICK_INC;
set_aclint_mtimecmp(aclint, time);
}
void __attribute__((weak)) default_handler(void) {
puts("default handler\n");
}
void __attribute__((weak)) interrupt_handler(unsigned) {
puts("interrupt handler\n");
}
uint32_t handle_trap(uint32_t mcause, uint32_t mepc, uint32_t sp){
if ((mcause & MCAUSE_INT)) {
if ((mcause & MCAUSE_CAUSE) == IRQ_M_EXT) {
handle_m_ext_interrupt();
} else if (((mcause & MCAUSE_CAUSE) == IRQ_M_TIMER)){
handle_m_time_interrupt();
} else {
interrupt_handler(mcause& ~MCAUSE_INT);
}
} else {
write(1, "trap\n", 5);
_exit(1 + mcause);
}
return mepc;
}
void _init()
{
#ifndef NO_INIT
init_pll();
uart_init(115200);
printf("core freq at %lu Hz\n", get_cpu_freq());
write_csr(mtvec, &trap_entry);
if (read_csr(misa) & (1 << ('F' - 'A'))) { // if F extension is present
write_csr(mstatus, MSTATUS_FS); // allow FPU instructions without trapping
write_csr(fcsr, 0); // initialize rounding mode, undefined at reset
}
int i=0;
while(i<NUM_INTERRUPTS) {
localISR[i++] = default_handler;
}
#endif
}
void _fini(void)
{
}