88 lines
1.6 KiB
C
88 lines
1.6 KiB
C
//See LICENSE for license details.
|
|
#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();
|
|
|
|
static unsigned long get_cpu_freq()
|
|
{
|
|
return 65000000;
|
|
}
|
|
|
|
unsigned long get_timer_freq()
|
|
{
|
|
return get_cpu_freq();
|
|
}
|
|
|
|
uint64_t get_timer_value()
|
|
{
|
|
#if __riscv_xlen == 32
|
|
while (1) {
|
|
uint32_t hi = read_csr(mcycleh);
|
|
uint32_t lo = read_csr(mcycle);
|
|
if (hi == read_csr(mcycleh))
|
|
return ((uint64_t)hi << 32) | lo;
|
|
}
|
|
#else
|
|
return read_csr(mcycle);
|
|
#endif
|
|
}
|
|
|
|
static void uart_init(size_t baud_rate)
|
|
{
|
|
GPIO_REG(GPIO_IOF_SEL) &= ~IOF0_UART0_MASK;
|
|
GPIO_REG(GPIO_IOF_EN) |= IOF0_UART0_MASK;
|
|
UART0_REG(UART_REG_DIV) = get_cpu_freq() / baud_rate - 1;
|
|
UART0_REG(UART_REG_TXCTRL) |= UART_TXEN;
|
|
}
|
|
|
|
|
|
#ifdef USE_PLIC
|
|
extern void handle_m_ext_interrupt();
|
|
#endif
|
|
|
|
#ifdef USE_M_TIME
|
|
extern void handle_m_time_interrupt();
|
|
#endif
|
|
|
|
uintptr_t handle_trap(uintptr_t mcause, uintptr_t epc)
|
|
{
|
|
if (0){
|
|
#ifdef USE_PLIC
|
|
// External Machine-Level interrupt from PLIC
|
|
} else if ((mcause & MCAUSE_INT) && ((mcause & MCAUSE_CAUSE) == IRQ_M_EXT)) {
|
|
handle_m_ext_interrupt();
|
|
#endif
|
|
#ifdef USE_M_TIME
|
|
// External Machine-Level interrupt from PLIC
|
|
} else if ((mcause & MCAUSE_INT) && ((mcause & MCAUSE_CAUSE) == IRQ_M_TIMER)){
|
|
handle_m_time_interrupt();
|
|
#endif
|
|
}
|
|
else {
|
|
write(1, "Unhandled Trap:\n", 16);
|
|
_exit(1 + mcause);
|
|
}
|
|
return epc;
|
|
}
|
|
|
|
void _init()
|
|
{
|
|
#ifndef NO_INIT
|
|
uart_init(115200);
|
|
|
|
printf("core freq at %d Hz\n", get_cpu_freq());
|
|
|
|
write_csr(mtvec, &trap_entry);
|
|
#endif
|
|
}
|
|
|
|
void _fini()
|
|
{
|
|
}
|