port over some instructions from the old code, add instruction table

This commit is contained in:
Matt Laux 2019-04-18 17:51:43 -05:00
parent 1bd3dc8e28
commit d7148739c7
5 changed files with 393 additions and 18 deletions

13
get_opcodes.js Normal file
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@ -0,0 +1,13 @@
let total = 0;
for (let row = 1; row < rows.length; row++) {
let cols = rows[row].getElementsByTagName("td");
for (let col = 1; col < cols.length; col++) {
let html = cols[col].innerHTML;
if (html.indexOf("<br>") != -1) {
html = html.substring(0, html.indexOf("<br>"));
}
console.log("{ 0x" + total.toString(16) + ", \"" + html + "\" },");
total++;
}
}

119
src/cpu.c
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@ -3,6 +3,7 @@
#include "cpu.h"
#include "types.h"
#include "instructions.h"
void cpu_bind_mem_model(
struct cpu *cpu,
@ -15,6 +16,21 @@ void cpu_bind_mem_model(
cpu->mem_write = mem_write;
}
static inline int flag_isset(struct cpu *cpu, int flag)
{
return (cpu->f & flag) != 0;
}
static inline void set_flag(struct cpu *cpu, int flag)
{
cpu->f |= flag;
}
static inline void clear_flag(struct cpu *cpu, int flag)
{
cpu->f &= ~flag;
}
static inline u16 read_af(struct cpu *cpu)
{
return cpu->a << 8 | cpu->f;
@ -35,6 +51,11 @@ static inline u16 read_hl(struct cpu *cpu)
return cpu->h << 8 | cpu->l;
}
static inline u16 read_double_reg(struct cpu *cpu, u8 *rh, u8 *rl)
{
return *rh << 8 | *rl;
}
static inline void write_af(struct cpu *cpu, int value)
{
cpu->a = value >> 8;
@ -53,16 +74,20 @@ static inline void write_de(struct cpu *cpu, int value)
cpu->e = value & 0xff;
}
static inline void write_hl(struct cpu *cpu, int value)
// TODO figure out if I like this style better and convert write_af, etc to this
static inline void write_double_reg(struct cpu *cpu, u8 *rh, u8 *rl, int value)
{
cpu->h = value >> 8;
cpu->l = value & 0xff;
*rh = value >> 8;
*rl = value & 0xff;
}
#define write_hl(cpu, value) write_double_reg((cpu), &cpu->h, &cpu->l, value)
void cpu_panic(struct cpu *cpu)
{
printf("a=%02x f=%02x b=%02x c=%02x\n", cpu->a, cpu->f, cpu->b, cpu->c);
printf("d=%02x e=%02x h=%02x l=%02x\n", cpu->d, cpu->e, cpu->h, cpu->l);
printf("sp=%04x pc=%04x\n", cpu->sp, cpu->pc);
exit(0);
}
@ -83,39 +108,105 @@ static inline void write8(struct cpu *cpu, u16 address, u8 data)
cpu->mem_write(cpu->mem_model, address, data);
}
static inline void write16(struct cpu *cpu, u16 address, u16 data)
{
cpu->mem_write(cpu->mem_model, address, data);
}
static void inc_with_carry(struct cpu *regs, u8 *reg)
{
clear_flag(regs, FLAG_SIGN);
if(*reg == 0xff || *reg == 0x0f)
set_flag(regs, FLAG_HALF_CARRY);
(*reg)++;
if(*reg == 0)
set_flag(regs, FLAG_ZERO);
}
static void dec_with_carry(struct cpu *regs, u8 *reg)
{
set_flag(regs, FLAG_SIGN);
if(*reg == 0x00 || *reg == 0x10)
set_flag(regs, FLAG_HALF_CARRY);
(*reg)--;
if(*reg == 0)
set_flag(regs, FLAG_ZERO);
}
static void rotate_left(struct cpu *regs, u8 *reg)
{
// copy old leftmost bit to carry flag
regs->f = (*reg & 0x80) >> 3 | (regs->f & ~FLAG_CARRY);
// rotate
*reg <<= 1;
// restore leftmost (now rightmost) bit
*reg |= (regs->f & FLAG_CARRY) >> 4;
}
static void rotate_right(struct cpu *regs, u8 *reg)
{
// copy old rightmost bit to carry flag
regs->f = (*reg & 0x01) << 4 | (regs->f & ~FLAG_CARRY);
// rotate
*reg >>= 1;
// restore rightmost bit to left
*reg |= (regs->f & FLAG_CARRY) << 3;
}
static void xor(struct cpu *regs, u8 value)
{
regs->a ^= value;
if(regs->a == 0)
set_flag(regs, FLAG_ZERO);
clear_flag(regs, FLAG_SIGN);
clear_flag(regs, FLAG_HALF_CARRY);
clear_flag(regs, FLAG_CARRY);
}
void cpu_step(struct cpu *cpu)
{
u8 opc = cpu->mem_read(cpu->mem_model, cpu->pc);
cpu->pc++;
switch (opc) {
case 0: // NOP
cpu->pc++;
break;
case 0x01: // LD BC, 0xNNNN
write_bc(cpu, read16(cpu, cpu->pc));
cpu->pc += 2;
break;
case 0x03: // INC BC
write_bc(cpu, read_bc(cpu) + 1);
break;
case 0x04: // INC B
inc_with_carry(cpu, &cpu->b);
break;
case 0x05: // DEC B
dec_with_carry(cpu, &cpu->b);
break;
case 0x06: // LD B, d8
cpu->b = read8(cpu, cpu->pc + 1);
cpu->pc += 2;
cpu->b = read8(cpu, cpu->pc);
cpu->pc += 1;
break;
case 0x0e: // LD C, d8
cpu->c = read8(cpu, cpu->pc + 1);
cpu->pc += 2;
cpu->c = read8(cpu, cpu->pc);
cpu->pc += 1;
break;
case 0x21: // LD HL, d16
write_hl(cpu, read16(cpu, cpu->pc + 1));
cpu->pc += 3;
write_hl(cpu, read16(cpu, cpu->pc));
cpu->pc += 2;
break;
case 0x32: // LD (HL-), A
write8(cpu, read_hl(cpu), cpu->a);
write_hl(cpu, read_hl(cpu) - 1);
cpu->pc++;
break;
case 0xc3: // JP a16
cpu->pc = read16(cpu, cpu->pc + 1);
cpu->pc = read16(cpu, cpu->pc);
break;
case 0xaf: // XOR A
cpu->a = 0;
cpu->pc++;
break;
default:
printf("unknown opcode %02x\n", opc);
printf("unknown opcode 0x%02x %s\n", opc, instructions[opc].format);
cpu_panic(cpu);
}
}

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@ -30,9 +30,9 @@ void cpu_bind_mem_model(
void cpu_step(struct cpu *cpu);
#define FLAG_Z(cpu) ((cpu)->f >> 7 & 1)
#define FLAG_N(cpu) ((cpu)->f >> 6 & 1)
#define FLAG_H(cpu) ((cpu)->f >> 5 & 1)
#define FLAG_C(cpu) ((cpu)->f >> 4 & 1)
#define FLAG_ZERO 0x80
#define FLAG_SIGN 0x40
#define FLAG_HALF_CARRY 0x20
#define FLAG_CARRY 0x10
#endif

260
src/instructions.c Normal file
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@ -0,0 +1,260 @@
#include "instructions.h"
const struct instruction instructions[] = {
{ 0x0, "NOP" },
{ 0x1, "LD BC,d16" },
{ 0x2, "LD (BC),A" },
{ 0x3, "INC BC" },
{ 0x4, "INC B" },
{ 0x5, "DEC B" },
{ 0x6, "LD B,d8" },
{ 0x7, "RLCA" },
{ 0x8, "LD (a16),SP" },
{ 0x9, "ADD HL,BC" },
{ 0xa, "LD A,(BC)" },
{ 0xb, "DEC BC" },
{ 0xc, "INC C" },
{ 0xd, "DEC C" },
{ 0xe, "LD C,d8" },
{ 0xf, "RRCA" },
{ 0x10, "STOP 0" },
{ 0x11, "LD DE,d16" },
{ 0x12, "LD (DE),A" },
{ 0x13, "INC DE" },
{ 0x14, "INC D" },
{ 0x15, "DEC D" },
{ 0x16, "LD D,d8" },
{ 0x17, "RLA" },
{ 0x18, "JR r8" },
{ 0x19, "ADD HL,DE" },
{ 0x1a, "LD A,(DE)" },
{ 0x1b, "DEC DE" },
{ 0x1c, "INC E" },
{ 0x1d, "DEC E" },
{ 0x1e, "LD E,d8" },
{ 0x1f, "RRA" },
{ 0x20, "JR NZ,r8" },
{ 0x21, "LD HL,d16" },
{ 0x22, "LD (HL+),A" },
{ 0x23, "INC HL" },
{ 0x24, "INC H" },
{ 0x25, "DEC H" },
{ 0x26, "LD H,d8" },
{ 0x27, "DAA" },
{ 0x28, "JR Z,r8" },
{ 0x29, "ADD HL,HL" },
{ 0x2a, "LD A,(HL+)" },
{ 0x2b, "DEC HL" },
{ 0x2c, "INC L" },
{ 0x2d, "DEC L" },
{ 0x2e, "LD L,d8" },
{ 0x2f, "CPL" },
{ 0x30, "JR NC,r8" },
{ 0x31, "LD SP,d16" },
{ 0x32, "LD (HL-),A" },
{ 0x33, "INC SP" },
{ 0x34, "INC (HL)" },
{ 0x35, "DEC (HL)" },
{ 0x36, "LD (HL),d8" },
{ 0x37, "SCF" },
{ 0x38, "JR C,r8" },
{ 0x39, "ADD HL,SP" },
{ 0x3a, "LD A,(HL-)" },
{ 0x3b, "DEC SP" },
{ 0x3c, "INC A" },
{ 0x3d, "DEC A" },
{ 0x3e, "LD A,d8" },
{ 0x3f, "CCF" },
{ 0x40, "LD B,B" },
{ 0x41, "LD B,C" },
{ 0x42, "LD B,D" },
{ 0x43, "LD B,E" },
{ 0x44, "LD B,H" },
{ 0x45, "LD B,L" },
{ 0x46, "LD B,(HL)" },
{ 0x47, "LD B,A" },
{ 0x48, "LD C,B" },
{ 0x49, "LD C,C" },
{ 0x4a, "LD C,D" },
{ 0x4b, "LD C,E" },
{ 0x4c, "LD C,H" },
{ 0x4d, "LD C,L" },
{ 0x4e, "LD C,(HL)" },
{ 0x4f, "LD C,A" },
{ 0x50, "LD D,B" },
{ 0x51, "LD D,C" },
{ 0x52, "LD D,D" },
{ 0x53, "LD D,E" },
{ 0x54, "LD D,H" },
{ 0x55, "LD D,L" },
{ 0x56, "LD D,(HL)" },
{ 0x57, "LD D,A" },
{ 0x58, "LD E,B" },
{ 0x59, "LD E,C" },
{ 0x5a, "LD E,D" },
{ 0x5b, "LD E,E" },
{ 0x5c, "LD E,H" },
{ 0x5d, "LD E,L" },
{ 0x5e, "LD E,(HL)" },
{ 0x5f, "LD E,A" },
{ 0x60, "LD H,B" },
{ 0x61, "LD H,C" },
{ 0x62, "LD H,D" },
{ 0x63, "LD H,E" },
{ 0x64, "LD H,H" },
{ 0x65, "LD H,L" },
{ 0x66, "LD H,(HL)" },
{ 0x67, "LD H,A" },
{ 0x68, "LD L,B" },
{ 0x69, "LD L,C" },
{ 0x6a, "LD L,D" },
{ 0x6b, "LD L,E" },
{ 0x6c, "LD L,H" },
{ 0x6d, "LD L,L" },
{ 0x6e, "LD L,(HL)" },
{ 0x6f, "LD L,A" },
{ 0x70, "LD (HL),B" },
{ 0x71, "LD (HL),C" },
{ 0x72, "LD (HL),D" },
{ 0x73, "LD (HL),E" },
{ 0x74, "LD (HL),H" },
{ 0x75, "LD (HL),L" },
{ 0x76, "HALT" },
{ 0x77, "LD (HL),A" },
{ 0x78, "LD A,B" },
{ 0x79, "LD A,C" },
{ 0x7a, "LD A,D" },
{ 0x7b, "LD A,E" },
{ 0x7c, "LD A,H" },
{ 0x7d, "LD A,L" },
{ 0x7e, "LD A,(HL)" },
{ 0x7f, "LD A,A" },
{ 0x80, "ADD A,B" },
{ 0x81, "ADD A,C" },
{ 0x82, "ADD A,D" },
{ 0x83, "ADD A,E" },
{ 0x84, "ADD A,H" },
{ 0x85, "ADD A,L" },
{ 0x86, "ADD A,(HL)" },
{ 0x87, "ADD A,A" },
{ 0x88, "ADC A,B" },
{ 0x89, "ADC A,C" },
{ 0x8a, "ADC A,D" },
{ 0x8b, "ADC A,E" },
{ 0x8c, "ADC A,H" },
{ 0x8d, "ADC A,L" },
{ 0x8e, "ADC A,(HL)" },
{ 0x8f, "ADC A,A" },
{ 0x90, "SUB B" },
{ 0x91, "SUB C" },
{ 0x92, "SUB D" },
{ 0x93, "SUB E" },
{ 0x94, "SUB H" },
{ 0x95, "SUB L" },
{ 0x96, "SUB (HL)" },
{ 0x97, "SUB A" },
{ 0x98, "SBC A,B" },
{ 0x99, "SBC A,C" },
{ 0x9a, "SBC A,D" },
{ 0x9b, "SBC A,E" },
{ 0x9c, "SBC A,H" },
{ 0x9d, "SBC A,L" },
{ 0x9e, "SBC A,(HL)" },
{ 0x9f, "SBC A,A" },
{ 0xa0, "AND B" },
{ 0xa1, "AND C" },
{ 0xa2, "AND D" },
{ 0xa3, "AND E" },
{ 0xa4, "AND H" },
{ 0xa5, "AND L" },
{ 0xa6, "AND (HL)" },
{ 0xa7, "AND A" },
{ 0xa8, "XOR B" },
{ 0xa9, "XOR C" },
{ 0xaa, "XOR D" },
{ 0xab, "XOR E" },
{ 0xac, "XOR H" },
{ 0xad, "XOR L" },
{ 0xae, "XOR (HL)" },
{ 0xaf, "XOR A" },
{ 0xb0, "OR B" },
{ 0xb1, "OR C" },
{ 0xb2, "OR D" },
{ 0xb3, "OR E" },
{ 0xb4, "OR H" },
{ 0xb5, "OR L" },
{ 0xb6, "OR (HL)" },
{ 0xb7, "OR A" },
{ 0xb8, "CP B" },
{ 0xb9, "CP C" },
{ 0xba, "CP D" },
{ 0xbb, "CP E" },
{ 0xbc, "CP H" },
{ 0xbd, "CP L" },
{ 0xbe, "CP (HL)" },
{ 0xbf, "CP A" },
{ 0xc0, "RET NZ" },
{ 0xc1, "POP BC" },
{ 0xc2, "JP NZ,a16" },
{ 0xc3, "JP a16" },
{ 0xc4, "CALL NZ,a16" },
{ 0xc5, "PUSH BC" },
{ 0xc6, "ADD A,d8" },
{ 0xc7, "RST 00H" },
{ 0xc8, "RET Z" },
{ 0xc9, "RET" },
{ 0xca, "JP Z,a16" },
{ 0xcb, "PREFIX CB" },
{ 0xcc, "CALL Z,a16" },
{ 0xcd, "CALL a16" },
{ 0xce, "ADC A,d8" },
{ 0xcf, "RST 08H" },
{ 0xd0, "RET NC" },
{ 0xd1, "POP DE" },
{ 0xd2, "JP NC,a16" },
{ 0xd3, "&nbsp;" },
{ 0xd4, "CALL NC,a16" },
{ 0xd5, "PUSH DE" },
{ 0xd6, "SUB d8" },
{ 0xd7, "RST 10H" },
{ 0xd8, "RET C" },
{ 0xd9, "RETI" },
{ 0xda, "JP C,a16" },
{ 0xdb, "&nbsp;" },
{ 0xdc, "CALL C,a16" },
{ 0xdd, "&nbsp;" },
{ 0xde, "SBC A,d8" },
{ 0xdf, "RST 18H" },
{ 0xe0, "LDH (a8),A" },
{ 0xe1, "POP HL" },
{ 0xe2, "LD (C),A" },
{ 0xe3, "&nbsp;" },
{ 0xe4, "&nbsp;" },
{ 0xe5, "PUSH HL" },
{ 0xe6, "AND d8" },
{ 0xe7, "RST 20H" },
{ 0xe8, "ADD SP,r8" },
{ 0xe9, "JP (HL)" },
{ 0xea, "LD (a16),A" },
{ 0xeb, "&nbsp;" },
{ 0xec, "&nbsp;" },
{ 0xed, "&nbsp;" },
{ 0xee, "XOR d8" },
{ 0xef, "RST 28H" },
{ 0xf0, "LDH A,(a8)" },
{ 0xf1, "POP AF" },
{ 0xf2, "LD A,(C)" },
{ 0xf3, "DI" },
{ 0xf4, "&nbsp;" },
{ 0xf5, "PUSH AF" },
{ 0xf6, "OR d8" },
{ 0xf7, "RST 30H" },
{ 0xf8, "LD HL,SP+r8" },
{ 0xf9, "LD SP,HL" },
{ 0xfa, "LD A,(a16)" },
{ 0xfb, "EI" },
{ 0xfc, "&nbsp;" },
{ 0xfd, "&nbsp;" },
{ 0xfe, "CP d8" },
{ 0xff, "RST 38H" },
};

11
src/instructions.h Normal file
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@ -0,0 +1,11 @@
#ifndef _INSTRUCTIONS_H
#define _INSTRUCTIONS_H
struct instruction {
int opcode;
const char *format;
};
extern const struct instruction instructions[];
#endif