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implement more ops

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This commit is contained in:
Antoni Piasecki
2025-07-11 14:48:48 +02:00
parent 7133d0491a
commit 975e8939d0
1 changed files with 25 additions and 12 deletions
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37
chip8.c
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@@ -59,6 +59,8 @@ void chip8_disassemble(CHIP8 *c, size_t ins_count) {
for (size_t i = 0; i < ins_count; i++) {
READ_INS();
printf("0x%x: ", c->pc);
switch ((ins >> 12) & 0xF) {
case 0x0: {
switch (nnn) {
@@ -73,7 +75,7 @@ void chip8_disassemble(CHIP8 *c, size_t ins_count) {
}
} break;
case 0x1: {
printf("JP %u\n", nnn);
printf("JP 0x%x\n", nnn);
} break;
case 0x2: {
printf("CALL %u\n", nnn);
@@ -130,7 +132,7 @@ void chip8_disassemble(CHIP8 *c, size_t ins_count) {
printf("SNE V%x, V%x\n", x, y);
} break;
case 0xA: {
printf("LD I, %u\n", nnn);
printf("LD I, 0x%x\n", nnn);
} break;
case 0xB: {
printf("JP V0, %u\n", nnn);
@@ -253,20 +255,26 @@ void chip8_execute(CHIP8 *c) {
case 0x3:
c->reg[x] ^= c->reg[y];
break;
case 0x4:
printf("TODO: ADD V%x, V%x\n", x, y);
break;
case 0x4: {
uint16_t res = (uint16_t)(c->reg[x]) + (uint16_t)c->reg[y];
c->reg[0xF] = res > 0xFF;
c->reg[x] = (uint8_t)(res & 0xFF);
} break;
case 0x5:
printf("TODO: SUB V%x, V%x\n", x, y);
c->reg[0xF] = c->reg[x] > c->reg[y];
c->reg[x] -= c->reg[y];
break;
case 0x6:
printf("TODO: SHR V%x\n", x);
c->reg[0xF] = c->reg[x] & 0x1;
c->reg[x] >>= 1;
break;
case 0x7:
printf("TODO: SUBN V%x, V%x\n", x, y);
c->reg[0xF] = c->reg[y] > c->reg[x];
c->reg[x] = c->reg[y] - c->reg[x];
break;
case 0xE:
printf("TODO: SHL V%x\n", x);
c->reg[0xF] = (c->reg[x] & 0b10000000) >> 7;
c->reg[x] <<= 1;
break;
default:
BAD_INS();
@@ -319,7 +327,7 @@ void chip8_execute(CHIP8 *c) {
c->I += c->reg[x];
break;
case 0x29:
printf("TODO: LD F, V%x\n", x);
c->I = c->reg[x] * 5;
break;
case 0x33:
c->memory[c->I] = c->reg[x] / 100;
@@ -327,10 +335,14 @@ void chip8_execute(CHIP8 *c) {
c->memory[c->I + 2] = c->reg[x] % 10;
break;
case 0x55:
printf("TODO: LD [I], V%x\n", x);
for (size_t i = 0; i <= x; i++) {
c->memory[c->I + i] = c->reg[i];
}
break;
case 0x65:
printf("TODO: LD V%x, [I]\n", x);
for (size_t i = 0; i <= x; i++) {
c->reg[i] = c->memory[c->I + i];
}
break;
default:
BAD_INS();
@@ -361,6 +373,7 @@ int main(int argc, char *argv[]) {
c.memory[0x200 + i] = buffer[i];
}
// chip8_disassemble(&c, n / 2);
chip8_execute(&c);
chip8_free(c);