diff options
Diffstat (limited to 'instr.c')
| -rw-r--r-- | instr.c | 149 |
1 files changed, 149 insertions, 0 deletions
@@ -0,0 +1,149 @@ +typedef enum +{ + C8_ILL, +/* Onnn = 0,1,2,A,B */ +/* 00E0 - CLS */ C8_CLS, +/* 00EE - RET */ C8_RET, +/* 0nnn - SYS addr */ C8_SYS, +/* 1nnn - JP addr */ C8_JP, +/* 2nnn - CALL addr */ C8_CALL, +/* Annn - LD I, addr */ C8_LDI, +/* Bnnn - JP V0, addr */ C8_JPV, +/* Oxkk = 3,4,6,7,C,E,F */ +/* 3xkk - SE Vx, byte */ C8_SEB, +/* 4xkk - SNE Vx, byte */ C8_SNEB, +/* 6xkk - LD Vx, byte */ C8_LD, +/* 7xkk - ADD Vx, byte */ C8_ADDB, +/* Cxkk - RND Vx, byte */ C8_RND, +/* Ex9E - SKP Vx */ C8_SKP, +/* ExA1 - SKNP Vx */ C8_SKNP, +/* Fx07 - LD Vx, DT */ C8_MVDT, +/* Fx0A - LD Vx, K */ C8_LDK, +/* Fx15 - LD DT, Vx */ C8_LDDT, +/* Fx18 - LD ST, Vx */ C8_LDST, +/* Fx1E - ADD I, Vx */ C8_ADDI, +/* Fx29 - LD F, Vx */ C8_HEX, +/* Fx33 - LD B, Vx */ C8_BCD, +/* Fx55 - LD [I], Vx */ C8_SAVE, +/* Fx65 - LD Vx, [I] */ C8_RESTORE, +/* Oxyn = 5,8,9,D */ +/* 5xy0 - SE Vx, Vy */ C8_SE, +/* 8xy0 - LD Vx, Vy */ C8_MOVE, +/* 8xy1 - OR Vx, Vy */ C8_OR, +/* 8xy2 - AND Vx, Vy */ C8_AND, +/* 8xy3 - XOR Vx, Vy */ C8_XOR, +/* 8xy4 - ADD Vx, Vy */ C8_ADD, +/* 8xy5 - SUB Vx, Vy */ C8_SUB, +/* 8xy6 - SHR Vx {, Vy} */ C8_SHR, +/* 8xy7 - SUBN Vx, Vy */ C8_SUBN, +/* 8xyE - SHL Vx {, Vy} */ C8_SHL, +/* 9xy0 - SNE Vx, Vy */ C8_SNE, +/* Dxyn - DRW Vx, Vy, nibble */ C8_DRW, + C8_OP_CNT + +} chip8_op; + +typedef void (*instr_func)(chip8* c8, chip8_op op, u16 nnn, u8 x, u8 y, u8 n, u8 kk); + + +const char* chip8_disasm_fmts[C8_OP_CNT] = +{ + "ILL unknown", + "CLS", + "RET", + "SYS %03X", + "JP %03X", + "CALL %03X", + "LD I, %03X", + "JP V0, %03X", + "SE V%-2x, %-2d", + "SNE V%-2x, %-2d", + "LD V%-2x, %-2d", + "ADD V%-2x, %-2d", + "RND V%-2x, %-2d", + "SKP V%-2x", + "SKNP V%-2x", + "LD V%-2x, DT", + "LD V%-2x, K", + "LD DT, V%-2x", + "LD ST, V%-2x", + "ADD I, V%-2x", + "LD F, V%-2x", + "LD B, V%-2x", + "LD [I], V%-2x", + "LD V%-2x, [I]", + "SE V%-2x, V%-2x", + "LD V%-2x, V%-2x", + "OR V%-2x, V%-2x", + "AND V%-2x, V%-2x", + "XOR V%-2x, V%-2x", + "ADD V%-2x, V%-2x", + "SUB V%-2x, V%-2x", + "SHR V%-2x, V%-2x", + "SUBN V%-2x, V%-2x", + "SHL V%-2x, V%-2x", + "SNE V%-2x, V%-2x", + "DRW V%-2x, V%-2x, %-1d" +}; + +void c8_decode(u8* code, u16 offset, instr_func func, chip8* c8); +void c8_disasm(chip8* c8, chip8_op op, u16 nnn, u8 x, u8 y, u8 n, u8 kk); +void c8_do(chip8* c8, chip8_op op, u16 nnn, u8 x, u8 y, u8 n, u8 kk); + +void c8_decode(u8* code, u16 offset, instr_func func, chip8* c8) +{ + chip8_op op = C8_ILL; + u16 word, instr, nnn; + u8 o, x, y, n, kk; + + word = *(u16*)(code + offset); + instr = be16toh(word); + o = (instr & 0xF000) >> 12; + nnn = (instr & 0x0FFF); + x = (instr & 0x0F00) >> 8; + y = (instr & 0x00F0) >> 4; + n = (instr & 0x000F); + kk = (instr & 0x00FF); + + if(o == 0 && nnn == 0x0E0) op = C8_CLS; + else if(o == 0 && nnn == 0x0EE) op = C8_RET; + else if(o == 0) op = C8_SYS; + else if(o == 1) op = C8_JP; + else if(o == 2) op = C8_CALL; + else if(o == 0xA) op = C8_LDI; + else if(o == 0xB) op = C8_JPV; + else if(o == 3) op = C8_SEB; + else if(o == 4) op = C8_SNEB; + else if(o == 6) op = C8_LD; + else if(o == 7) op = C8_ADDB; + else if(o == 0xC) op = C8_RND; + else if(o == 0xE && kk == 0x9E) op = C8_SKP; + else if(o == 0xE && kk == 0xA1) op = C8_SKNP; + else if(o == 0xF && kk == 0x07) op = C8_MVDT; + else if(o == 0xF && kk == 0x0A) op = C8_LDK; + else if(o == 0xF && kk == 0x15) op = C8_LDDT; + else if(o == 0xF && kk == 0x18) op = C8_LDST; + else if(o == 0xF && kk == 0x1E) op = C8_ADDI; + else if(o == 0xF && kk == 0x29) op = C8_HEX; + else if(o == 0xF && kk == 0x33) op = C8_BCD; + else if(o == 0xF && kk == 0x55) op = C8_SAVE; + else if(o == 0xF && kk == 0x65) op = C8_RESTORE; + else if(o == 5 && n == 0) op = C8_SE; + else if(o == 8 && n == 0) op = C8_MOVE; + else if(o == 8 && n == 1) op = C8_OR; + else if(o == 8 && n == 2) op = C8_AND; + else if(o == 8 && n == 3) op = C8_XOR; + else if(o == 8 && n == 4) op = C8_ADD; + else if(o == 8 && n == 5) op = C8_SUB; + else if(o == 8 && n == 6) op = C8_SHR; + else if(o == 8 && n == 7) op = C8_SUBN; + else if(o == 8 && n == 0xE) op = C8_SHL; + else if(o == 9 && n == 0) op = C8_SNE; + else if(o == 0xD) op = C8_DRW; + + func(c8, op, nnn, x, y, n, kk); +} + +void c8_disasm(chip8* c8, chip8_op op, u16 nnn, u8 x, u8 y, u8 kk, u8 n); +void c8_do(chip8* c8, chip8_op op, u16 nnn, u8 x, u8 y, u8 kk, u8 n); + |