| swissChili | 6c61a79 | 2020-07-28 16:29:20 -0700 | [diff] [blame^] | 1 | #pragma once |
| 2 | |
| 3 | #include <stdint.h> |
| 4 | |
| 5 | enum // Registers |
| 6 | { |
| 7 | A, X, Y, SR, SP |
| 8 | }; |
| 9 | |
| 10 | enum // Flags |
| 11 | { |
| 12 | CARRY = 1 << 0, |
| 13 | ZERO = 1 << 1, |
| 14 | NO_INT = 1 << 2, |
| 15 | DECIMAL = 1 << 3, |
| 16 | BREAK = 1 << 4, |
| 17 | UNUSED = 1 << 5, |
| 18 | OVERFLW = 1 << 6, |
| 19 | NEGATIV = 1 << 7, |
| 20 | }; |
| 21 | |
| 22 | enum // Address Modes |
| 23 | { |
| 24 | AM_ACC, // Accumulator implied as operand |
| 25 | AM_IMP, // Implied operand |
| 26 | AM_IMM, // Immediate operand (8 bit) |
| 27 | AM_ABS, // Absolute operand (16 bit) |
| 28 | AM_ZP, // Zero-page operand |
| 29 | AM_REL, // Relative operand (signed 8 bit) |
| 30 | AM_IND, // Absolute indirect operand (16 bit address of 16 bit address) |
| 31 | AM_AX, // Absolute indexed with X |
| 32 | AM_AY, // Absolute indexed with Y |
| 33 | AM_ZPX, // Zero-page indexed with X |
| 34 | AM_ZPY, // Zero-page indexed with Y |
| 35 | AM_ZIX, // Zero-page indexed indirect (zp,x) |
| 36 | AM_ZIY, // Zero-page indirect indexed (zp),y |
| 37 | }; |
| 38 | |
| 39 | enum // Opcodes |
| 40 | { |
| 41 | LDA, |
| 42 | LDX, |
| 43 | LDY, |
| 44 | STA, |
| 45 | STX, |
| 46 | STY, |
| 47 | ADC, |
| 48 | SBC, |
| 49 | INC, |
| 50 | INX, |
| 51 | INY, |
| 52 | DEC, |
| 53 | DEX, |
| 54 | DEY, |
| 55 | ASL, |
| 56 | LSR, |
| 57 | ROL, |
| 58 | ROR, |
| 59 | AND, |
| 60 | ORA, |
| 61 | EOR, |
| 62 | CMP, |
| 63 | CPX, |
| 64 | CPY, |
| 65 | BIT, |
| 66 | BCC, |
| 67 | BCS, |
| 68 | BNE, |
| 69 | BEQ, |
| 70 | BPL, |
| 71 | BMI, |
| 72 | BVC, |
| 73 | BVS, |
| 74 | TAX, |
| 75 | TXA, |
| 76 | TAY, |
| 77 | TYA, |
| 78 | TSX, |
| 79 | TXS, |
| 80 | PHA, |
| 81 | PLA, |
| 82 | PHP, |
| 83 | PLP, |
| 84 | JMP, |
| 85 | JSR, |
| 86 | RTS, |
| 87 | RTI, |
| 88 | CLC, |
| 89 | SEC, |
| 90 | CLD, |
| 91 | SED, |
| 92 | CLI, |
| 93 | SEI, |
| 94 | CLV, |
| 95 | BRK, |
| 96 | NOP, |
| 97 | }; |
| 98 | |
| 99 | // Emulator instance, create with new_cpu() |
| 100 | typedef struct |
| 101 | { |
| 102 | uint8_t regs[5]; // A, X, Y, SP and SR registers |
| 103 | uint16_t pc; |
| 104 | uint8_t *mem; |
| 105 | } cpu_t; |
| 106 | |
| 107 | // Argument type, includes both pointer and its value |
| 108 | typedef struct |
| 109 | { |
| 110 | uint16_t val; // Value at pointer (used by most instructions) |
| 111 | uint16_t ptr; // Pointer (used by jumps, etc) |
| 112 | } arg_t; |
| 113 | |
| 114 | cpu_t new_cpu(); |
| 115 | void free_cpu(cpu_t *cpu); |
| 116 | void die(const char *message); |
| 117 | void disas(cpu_t *cpu); |