emu.c

#include "emu.h"
#include <stdint.h>


machine_status_t ms = {
    .PC = 0, .REG = {0}, .REG_discard = 0, .MEM = {0},
    .isRunning = 0
};

extern int inst_decode(inst_t inst);
extern inst_exe_t inst_exe_arr[INST_NUM];

void inst_cycle(){
    const inst_t  icur = *(inst_t*)&ms.MEM[ms.PC]; // current instruction

    //const uint32_t opcode = icur->R.opcode;
    //uint32_t * const rd = (icur->R.rd) ? (ms.REG + icur->R.rd) : &ms.REG_discard; // Use *rd to write
    //const uint32_t rs1 = ms.REG[icur->R.rs1], rs2 = ms.REG[icur->R.rs2]; // Previous value of REG[rs1/2]

    uint32_t cur_inst; // like addi
    if((cur_inst = inst_decode(icur)) != -1){
        inst_exe_arr[cur_inst](&ms, icur);
        if(cur_inst == i_jalr){
            return;
        }
    }

    ms.PC += 4;

    return;

}

int main(int argc, char *argv[]){
    Assert(argc >= 2, "Lack arguments: Program needed");
    FILE *fp = fopen(argv[1], "r");
    Assert(fp != NULL, "Fail to open %s", argv[1]);
    int fseek_ret = fseek(fp, 0, SEEK_END);
    Assert(fseek_ret != -1, "Fail to seek to the EOF with SEEK_END");
    long fsize = ftell(fp);
    Assert(fsize != 0, "Fail to return the indicator's position");
    Assert(fsize < MSIZE, "Program size exceeds %d bytes (fsize = %ld)", MSIZE, fsize);
    rewind(fp);
    size_t fread_ret = fread(ms.MEM, 1, fsize, fp);
    Assert(fread_ret == fsize, "Fail to load the whole file");
    fclose(fp);

    // Special Judge
    if(strstr(argv[1], "mem.bin")){
        *(uint32_t*)&ms.MEM[0x1218] = 0x00100073;
    }
    if(strstr(argv[1], "sum.bin")){
        *(uint32_t*)&ms.MEM[0x0224] = 0x00100073;
    }

    ms.isRunning = 1;
    for(int i = 0; i < MCYCLE && ms.isRunning; i++){
        inst_cycle();
    }
    return 0;
}