view emulator/emu.c @ 14:2b8eb2c86602

Major update to assembler design, now handles labels proper.
Next step unit test

Added boot procedure and experimental function look up table to emulator
Started implementing operations
tested SET and CLR operations with success

/* emu.c
 * ema00ulation start up and fetch/decode/execute loop */
#include <stdio.h>
#include <string.h>
#include "mem.h"
#include "iset.h"

/* instruction table */
void (*iset[256])(void) = {
    NOP, RESERVED, RESERVED, RESERVED, RESERVED, RESERVED, RESERVED, RESERVED,
    SET, CLR, SET, CLR, SET, CLR, CPL, CPL,
    XCSD, SFA, LAF, MOV, MOV, MOV, MOV, MOV,
    MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
    MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
    MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
    MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
    MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
    MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
    MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
    MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
    MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
    MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
    MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
    MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
    MOV, MOV, MOV, MOV, MOV, MOV, MOV, MOV,
    ANL, ANL, ANL, ANL, ANL, ANL, ANL, ANL,
    ORL, ORL, ORL, ORL, ORL, ORL, ORL, ORL,
    XRL, XRL, XRL, XRL, XRL, XRL, XRL, XRL,
    RL, RLC, RR, RRC, INC, DEC, INC, DEC,
    ADD, ADD, ADD, ADD, ADD, ADD, ADD, ADD,
    ADDC, ADDC, ADDC, ADDC, ADDC, ADDC, ADDC, ADDC,
    SUB, SUB, SUB, SUB, SUB, SUB, SUB, SUB,
    SUBB, SUBB, SUBB, SUBB, SUBB, SUBB, SUBB, SUBB,
    PJMP, PJMP, PJMP, PJMP, PJMP, PJMP, PJMP, PJMP,
    PCALL, PCALL, PCALL, PCALL, PCALL, PCALL, PCALL, PCALL,
    DJNZ, DJNZ, DJNZ, DJNZ, CJNE, CJNE, CJNE, CJNE,
    LJMP, LCALL, RET, RETI, SJMP, JMP, JMP, CJNE,
    JZ, JNZ, JC, JNC, JPO, JPE, JS, JNS,
    PUSH, PUSH, PUSH, PUSH, PUSH, PUSH, PUSH, PUSH,
    POP, POP, POP, POP, POP, POP, POP, POP,
    MUL, DIV, DA, RESERVED, IN, OUT, INT, HLT
};


void
boot(void) {
    /* set everything to zero */
    memset(&registers, 0, sizeof(registers));
    memset(&memory, 0, sizeof(memory));

    /* load program from stdin
     * c must be signed since EOF is -1 on linux */
    WIDE i = 0;
    BYTE c = getchar();
    for(i ; i < 0x10000 ; i++) {
        /* add HLT if EOF is reached */
        if ((signed char) c == EOF) { 
            memory[i] = 0xFF;
            break; 
        }
        memory[i] = c;
        c = getchar();
    }
}

void 
step(void) {
    op = fetch();
    (*iset[op])();
}

void 
main(void) {
    boot();
    for (;;) { 
        step();
        putchar(registers.flags);
    }
}