123 lines
2.4 KiB
C
123 lines
2.4 KiB
C
//See LICENSE for license details.
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#include <stdint.h>
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#include <stdio.h>
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#include <unistd.h>
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#include "platform.h"
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#include "encoding.h"
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#define CPU_FREQ 65000000
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#define XSTR(x) #x
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#define STR(x) XSTR(x)
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#ifndef VECT_IRQ
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#define TRAP_ENTRY trap_entry
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#else
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#define TRAP_ENTRY vtrap_entry
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#endif
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extern int main(int argc, char** argv);
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extern void TRAP_ENTRY();
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unsigned long get_cpu_freq()
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{
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return CPU_FREQ;
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}
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unsigned long get_timer_freq()
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{
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return get_cpu_freq();
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}
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uint64_t get_timer_value()
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{
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#if __riscv_xlen == 32
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while (1) {
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uint32_t hi = read_csr(mcycleh);
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uint32_t lo = read_csr(mcycle);
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if (hi == read_csr(mcycleh))
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return ((uint64_t)hi << 32) | lo;
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}
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#else
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return read_csr(mcycle);
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#endif
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}
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static void uart_init(size_t baud_rate)
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{
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UART0_REG(UART_REG_DIV) = (get_cpu_freq() / 2) / baud_rate - 1;
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UART0_REG(UART_REG_TXCTRL) |= UART_TXEN;
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}
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#ifdef USE_PLIC
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extern void handle_m_ext_interrupt();
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#endif
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#ifdef USE_M_TIME
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extern void handle_m_time_interrupt();
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#endif
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#ifdef USE_LOCAL_ISR
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typedef void (*my_interrupt_function_ptr_t) (void);
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extern my_interrupt_function_ptr_t localISR[];
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#endif
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#ifndef VECT_IRQ
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uintptr_t handle_trap(uintptr_t mcause, uintptr_t epc) __attribute__((noinline));
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uintptr_t handle_trap(uintptr_t mcause, uintptr_t epc)
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{
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if (0){
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#ifdef USE_PLIC
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// External Machine-Level interrupt from PLIC
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} else if ((mcause & MCAUSE_INT) && ((mcause & MCAUSE_CAUSE) == IRQ_M_EXT)) {
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handle_m_ext_interrupt();
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#endif
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#ifdef USE_M_TIME
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// External Machine-Level interrupt from PLIC
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} else if ((mcause & MCAUSE_INT) && ((mcause & MCAUSE_CAUSE) == IRQ_M_TIMER)){
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handle_m_time_interrupt();
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#endif
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#ifdef USE_LOCAL_ISR
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} else if (mcause & MCAUSE_INT) {
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localISR[mcause & MCAUSE_CAUSE] ();
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#endif
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}
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else {
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write(1, "Unhandled Trap:\n", 16);
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_exit(1 + mcause);
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}
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return epc;
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}
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#endif
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#ifdef USE_CLIC
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void trap_entry(void) __attribute__((interrupt("SiFive-CLIC-preemptible"), aligned(64)));
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void trap_entry(void)
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{
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unsigned long mcause = read_csr(mcause);
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unsigned long mepc = read_csr(mepc);
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handle_trap(mcause, mepc);
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}
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#endif
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void _init()
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{
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#ifndef NO_INIT
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uart_init(115200);
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puts("core freq at " STR(CPU_FREQ) " Hz\n");
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#ifdef USE_CLIC
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write_csr(mtvec, ((unsigned long)&trap_entry | MTVEC_CLIC));
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#else
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write_csr(mtvec, ((unsigned long)&TRAP_ENTRY | MTVEC_VECTORED));
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#endif
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#endif
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}
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void _fini()
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{
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}
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