emu_nes/opcodes.h

#include <stdbool.h>
#include <stdint.h>

#include "cpu.h"

enum addressing_mode {
	AM_NONE,
	AM_ACC,
	AM_IMM,
	AM_REL,
	AM_ZP,
	AM_ZP_X,
	AM_ZP_Y,
	AM_ABS,
	AM_ABS_X,
	AM_ABS_Y,
	AM_IND,
	AM_IND_X,
	AM_IND_Y,
};

/* index of below array is the code of the instruction */
struct opcode {
	const char name[4];
	/* I know 16bit seems wasteful, but some ops use 16bit memory as arg */
	void (*instr)(uint16_t arg);
	uint8_t bytes;
	uint8_t cycles;
	bool memread;
	bool memwrite;
	enum addressing_mode mode;
};

struct opcode opcodes[0x100] = {
	/* official opcodes */
	[0x69] = { "ADC", ADC, 2, 2, false, false, AM_IMM },
	[0x65] = { "ADC", ADC, 2, 3, true,  false, AM_ZP },
	[0x75] = { "ADC", ADC, 2, 4, true,  false, AM_ZP_X },
	[0x6D] = { "ADC", ADC, 3, 4, true,  false, AM_ABS },
	[0x7D] = { "ADC", ADC, 3, 4, true,  false, AM_ABS_X },
	[0x79] = { "ADC", ADC, 3, 4, true,  false, AM_ABS_Y },
	[0x61] = { "ADC", ADC, 2, 6, true,  false, AM_IND_X },
	[0x71] = { "ADC", ADC, 2, 5, true,  false, AM_IND_Y },
	[0x29] = { "AND", AND, 2, 2, false, false, AM_IMM },
	[0x25] = { "AND", AND, 2, 3, true,  false, AM_ZP },
	[0x35] = { "AND", AND, 2, 4, true,  false, AM_ZP_X },
	[0x2D] = { "AND", AND, 3, 4, true,  false, AM_ABS },
	[0x3D] = { "AND", AND, 3, 4, true,  false, AM_ABS_X },
	[0x39] = { "AND", AND, 3, 4, true,  false, AM_ABS_Y },
	[0x21] = { "AND", AND, 2, 6, true,  false, AM_IND_X },
	[0x31] = { "AND", AND, 2, 5, true,  false, AM_IND_Y },
	[0x0A] = { "ASL", ASL_acc, 1, 2, false, false, AM_ACC },
	[0x06] = { "ASL", ASL, 2, 5, false, true, AM_ZP },
	[0x16] = { "ASL", ASL, 2, 6, false, true, AM_ZP_X },
	[0x0E] = { "ASL", ASL, 3, 6, false, true, AM_ABS },
	[0x1E] = { "ASL", ASL, 3, 7, false, true, AM_ABS_X },
	[0x90] = { "BCC", BCC, 2, 2, false, false, AM_REL },
	[0xB0] = { "BCS", BCS, 2, 2, false, false, AM_REL },
	[0xF0] = { "BEQ", BEQ, 2, 2, false, false, AM_REL },
	[0x24] = { "BIT", BIT, 2, 3, true,  false, AM_ZP },
	[0x2C] = { "BIT", BIT, 3, 4, true,  false, AM_ABS },
	[0x30] = { "BMI", BMI, 2, 2, false, false, AM_REL },
	[0xD0] = { "BNE", BNE, 2, 2, false, false, AM_REL },
	[0x10] = { "BPL", BPL, 2, 2, false, false, AM_REL },
	[0x00] = { "BRK", BRK, 1, 7, false, false, AM_NONE },
	[0x50] = { "BVC", BVC, 2, 2, false, false, AM_REL },
	[0x70] = { "BVS", BVS, 2, 2, false, false, AM_REL },
	[0x18] = { "CLC", CLC, 1, 2, false, false, AM_NONE },
	[0xD8] = { "CLD", CLD, 1, 2, false, false, AM_NONE },
	[0x58] = { "CLI", CLI, 1, 2, false, false, AM_NONE },
	[0xB8] = { "CLV", CLV, 1, 2, false, false, AM_NONE },
	[0xC9] = { "CMP", CMP, 2, 2, false, false, AM_IMM },
	[0xC5] = { "CMP", CMP, 2, 3, true,  false, AM_ZP },
	[0xD5] = { "CMP", CMP, 2, 4, true,  false, AM_ZP_X },
	[0xCD] = { "CMP", CMP, 3, 4, true,  false, AM_ABS },
	[0xDD] = { "CMP", CMP, 3, 4, true,  false, AM_ABS_X },
	[0xD9] = { "CMP", CMP, 3, 4, true,  false, AM_ABS_Y },
	[0xC1] = { "CMP", CMP, 2, 6, true,  false, AM_IND_X },
	[0xD1] = { "CMP", CMP, 2, 5, true,  false, AM_IND_Y },
	[0xE0] = { "CPX", CPX, 2, 2, false, false, AM_IMM },
	[0xE4] = { "CPX", CPX, 2, 3, true,  false, AM_ZP },
	[0xEC] = { "CPX", CPX, 3, 4, true,  false, AM_ABS },
	[0xC0] = { "CPY", CPY, 2, 2, false, false, AM_IMM },
	[0xC4] = { "CPY", CPY, 2, 3, true,  false, AM_ZP },
	[0xCC] = { "CPY", CPY, 3, 4, true,  false, AM_ABS },
	[0xC6] = { "DEC", DEC, 2, 5, false, true, AM_ZP },
	[0xD6] = { "DEC", DEC, 2, 6, false, true, AM_ZP_X },
	[0xCE] = { "DEC", DEC, 3, 6, false, true, AM_ABS },
	[0xDE] = { "DEC", DEC, 3, 7, false, true, AM_ABS_X },
	[0xCA] = { "DEX", DEX, 1, 2, false, false, AM_NONE },
	[0x88] = { "DEY", DEY, 1, 2, false, false, AM_NONE },
	[0x49] = { "EOR", EOR, 2, 2, false, false, AM_IMM },
	[0x45] = { "EOR", EOR, 2, 3, true,  false, AM_ZP },
	[0x55] = { "EOR", EOR, 2, 4, true,  false, AM_ZP_X },
	[0x4D] = { "EOR", EOR, 3, 4, true,  false, AM_ABS },
	[0x5D] = { "EOR", EOR, 3, 4, true,  false, AM_ABS_X },
	[0x59] = { "EOR", EOR, 3, 4, true,  false, AM_ABS_Y },
	[0x41] = { "EOR", EOR, 2, 6, true,  false, AM_IND_X },
	[0x51] = { "EOR", EOR, 2, 5, true,  false, AM_IND_Y },
	[0xE6] = { "INC", INC, 2, 5, false, true, AM_ZP },
	[0xF6] = { "INC", INC, 2, 6, false, true, AM_ZP_X },
	[0xEE] = { "INC", INC, 3, 6, false, true, AM_ABS },
	[0xFE] = { "INC", INC, 3, 7, false, true, AM_ABS_X },
	[0xE8] = { "INX", INX, 1, 2, false, false, AM_NONE },
	[0xC8] = { "INY", INY, 1, 2, false, false, AM_NONE },
	[0x4C] = { "JMP", JMP, 3, 3, false, false, AM_ABS },
	[0x6C] = { "JMP", JMP, 3, 5, false, false, AM_IND },
	[0x20] = { "JSR", JSR, 3, 6, false, false, AM_ABS },
	[0xA9] = { "LDA", LDA, 2, 2, false, false, AM_IMM },
	[0xA5] = { "LDA", LDA, 2, 3, true,  false, AM_ZP },
	[0xB5] = { "LDA", LDA, 2, 4, true,  false, AM_ZP_X },
	[0xAD] = { "LDA", LDA, 3, 4, true,  false, AM_ABS },
	[0xBD] = { "LDA", LDA, 3, 4, true,  false, AM_ABS_X },
	[0xB9] = { "LDA", LDA, 3, 4, true,  false, AM_ABS_Y },
	[0xA1] = { "LDA", LDA, 2, 6, true,  false, AM_IND_X },
	[0xB1] = { "LDA", LDA, 2, 5, true,  false, AM_IND_Y },
	[0xA2] = { "LDX", LDX, 2, 2, false, false, AM_IMM },
	[0xA6] = { "LDX", LDX, 2, 3, true,  false, AM_ZP },
	[0xB6] = { "LDX", LDX, 2, 4, true,  false, AM_ZP_Y },
	[0xAE] = { "LDX", LDX, 3, 4, true,  false, AM_ABS },
	[0xBE] = { "LDX", LDX, 3, 4, true,  false, AM_ABS_Y },
	[0xA0] = { "LDY", LDY, 2, 2, false, false, AM_IMM },
	[0xA4] = { "LDY", LDY, 2, 3, true,  false, AM_ZP },
	[0xB4] = { "LDY", LDY, 2, 4, true,  false, AM_ZP_X },
	[0xAC] = { "LDY", LDY, 3, 4, true,  false, AM_ABS },
	[0xBC] = { "LDY", LDY, 3, 4, true,  false, AM_ABS_X },
	[0x4A] = { "LSR", LSR_acc, 1, 2, false, false, AM_ACC },
	[0x46] = { "LSR", LSR, 2, 5, false, true, AM_ZP },
	[0x56] = { "LSR", LSR, 2, 6, false, true, AM_ZP_X },
	[0x4E] = { "LSR", LSR, 3, 6, false, true, AM_ABS },
	[0x5E] = { "LSR", LSR, 3, 7, false, true, AM_ABS_X },
	[0xEA] = { "NOP", NOP, 1, 2, false, false, AM_NONE },
	[0x09] = { "ORA", ORA, 2, 2, false, false, AM_IMM },
	[0x05] = { "ORA", ORA, 2, 3, true,  false, AM_ZP },
	[0x15] = { "ORA", ORA, 2, 4, true,  false, AM_ZP_X },
	[0x0D] = { "ORA", ORA, 3, 4, true,  false, AM_ABS },
	[0x1D] = { "ORA", ORA, 3, 4, true,  false, AM_ABS_X },
	[0x19] = { "ORA", ORA, 3, 4, true,  false, AM_ABS_Y },
	[0x01] = { "ORA", ORA, 2, 6, true,  false, AM_IND_X },
	[0x11] = { "ORA", ORA, 2, 5, true,  false, AM_IND_Y },
	[0x48] = { "PHA", PHA, 1, 3, false, false, AM_NONE },
	[0x08] = { "PHP", PHP, 1, 3, false, false, AM_NONE },
	[0x68] = { "PLA", PLA, 1, 4, false, false, AM_NONE },
	[0x28] = { "PLP", PLP, 1, 4, false, false, AM_NONE },
	[0x2A] = { "ROL", ROL_acc, 1, 2, false, false, AM_ACC },
	[0x26] = { "ROL", ROL, 2, 5, false, true, AM_ZP },
	[0x36] = { "ROL", ROL, 2, 6, false, true, AM_ZP_X },
	[0x2E] = { "ROL", ROL, 3, 6, false, true, AM_ABS },
	[0x3E] = { "ROL", ROL, 3, 7, false, true, AM_ABS_X },
	[0x6A] = { "ROR", ROR_acc, 1, 2, false, false, AM_ACC },
	[0x66] = { "ROR", ROR, 2, 5, false, true, AM_ZP },
	[0x76] = { "ROR", ROR, 2, 6, false, true, AM_ZP_X },
	[0x6E] = { "ROR", ROR, 3, 6, false, true, AM_ABS },
	[0x7E] = { "ROR", ROR, 3, 7, false, true, AM_ABS_X },
	[0x40] = { "RTI", RTI, 1, 6, false, false, AM_NONE },
	[0x60] = { "RTS", RTS, 1, 6, false, false, AM_NONE },
	[0xE9] = { "SBC", SBC, 2, 2, false, false, AM_IMM },
	[0xE5] = { "SBC", SBC, 2, 3, true,  false, AM_ZP },
	[0xF5] = { "SBC", SBC, 2, 4, true,  false, AM_ZP_X },
	[0xED] = { "SBC", SBC, 3, 4, true,  false, AM_ABS },
	[0xFD] = { "SBC", SBC, 3, 4, true,  false, AM_ABS_X },
	[0xF9] = { "SBC", SBC, 3, 4, true,  false, AM_ABS_Y },
	[0xE1] = { "SBC", SBC, 2, 6, true,  false, AM_IND_X },
	[0xF1] = { "SBC", SBC, 2, 5, true,  false, AM_IND_Y },
	[0x38] = { "SEC", SEC, 1, 2, false, false, AM_NONE },
	[0xF8] = { "SED", SED, 1, 2, false, false, AM_NONE },
	[0x78] = { "SEI", SEI, 1, 2, false, false, AM_NONE },
	[0x85] = { "STA", STA, 2, 3, false, true, AM_ZP },
	[0x95] = { "STA", STA, 2, 4, false, true, AM_ZP_X },
	[0x8D] = { "STA", STA, 3, 4, false, true, AM_ABS },
	[0x9D] = { "STA", STA, 3, 5, false, true, AM_ABS_X },
	[0x99] = { "STA", STA, 3, 5, false, true, AM_ABS_Y },
	[0x81] = { "STA", STA, 2, 6, false, true, AM_IND_X },
	[0x91] = { "STA", STA, 2, 6, false, true, AM_IND_Y },
	[0x86] = { "STX", STX, 2, 3, false, true, AM_ZP },
	[0x96] = { "STX", STX, 2, 4, false, true, AM_ZP_Y },
	[0x8E] = { "STX", STX, 3, 4, false, true, AM_ABS },
	[0x84] = { "STY", STY, 2, 3, false, true, AM_ZP },
	[0x94] = { "STY", STY, 2, 4, false, true, AM_ZP_X },
	[0x8C] = { "STY", STY, 3, 4, false, true, AM_ABS },
	[0xAA] = { "TAX", TAX, 1, 2, false, false, AM_NONE },
	[0xA8] = { "TAY", TAY, 1, 2, false, false, AM_NONE },
	[0xBA] = { "TSX", TSX, 1, 2, false, false, AM_NONE },
	[0x8A] = { "TXA", TXA, 1, 2, false, false, AM_NONE },
	[0x9A] = { "TXS", TXS, 1, 2, false, false, AM_NONE },
	[0x98] = { "TYA", TYA, 1, 2, false, false, AM_NONE },
};