diff options
Diffstat (limited to 'hacks/asm6502.h')
| -rw-r--r-- | hacks/asm6502.h | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/hacks/asm6502.h b/hacks/asm6502.h new file mode 100644 index 0000000..79b13a2 --- /dev/null +++ b/hacks/asm6502.h @@ -0,0 +1,181 @@ +/* + * Copyright (c) 2007 Jeremy English <jhe@jeremyenglish.org> + * + * Permission to use, copy, modify, distribute, and sell this software and its + * documentation for any purpose is hereby granted without fee, provided that + * the above copyright notice appear in all copies and that both that + * copyright notice and this permission notice appear in supporting + * documentation. No representations are made about the suitability of this + * software for any purpose. It is provided "as is" without express or + * implied warranty. + * + * Created: 07-May-2007 + */ + +/* + This is a port of the javascript 6502 assembler, compiler and + debugger. The orignal code was copyright 2006 by Stian Soreng - + www.6502asm.com + + The stack space is in page $100 to $1ff. The video buffer starts at + $200 and is 1024 bytes. Programs get loaded at address + $600. Address $fe is random and byte $ff is used for user input. + + User input is disabled. +*/ + +#ifndef __ASM6502_H__ +#define __ASM6502_H__ + +typedef uint8_t Bit8; +typedef uint16_t Bit16; +typedef uint32_t Bit32; + +#undef BOOL +#undef TRUE +#undef FALSE +#define BOOL Bit8 +#define TRUE 1 +#define FALSE 0 + +enum { + MAX_LABEL_LEN = 80, + NUM_OPCODES = 56, /* Number of unique instructions not counting DCB */ + MEM_64K = 65536, /* We have 64k of memory to work with. */ + MAX_PARAM_VALUE = 25, /* The number of values allowed behind dcb */ + MAX_CMD_LEN = 4, /* Each assembly command is 3 characeters long */ +/* The stack works from the top down in page $100 to $1ff */ + STACK_TOP = 0x1ff, + STACK_BOTTOM = 0x100, + PROG_START = 0x600 /* The default entry point for the program */ +}; + +typedef enum{ + SINGLE, IMMEDIATE_VALUE, IMMEDIATE_GREAT, + IMMEDIATE_LESS, INDIRECT_X, INDIRECT_Y, + ZERO, ZERO_X, ZERO_Y, + ABS_VALUE, ABS_OR_BRANCH, ABS_X, ABS_Y, + ABS_LABEL_X, ABS_LABEL_Y, DCB_PARAM +} m6502_AddrMode; + +typedef struct machine_6502 machine_6502; + +typedef struct { + char name[MAX_CMD_LEN]; + Bit8 Imm; + Bit8 ZP; + Bit8 ZPX; + Bit8 ZPY; + Bit8 ABS; + Bit8 ABSX; + Bit8 ABSY; + Bit8 INDX; + Bit8 INDY; + Bit8 SNGL; + Bit8 BRA; + void (*func) (machine_6502*, m6502_AddrMode); +} m6502_Opcodes; + +/* Used to cache the index of each opcode */ +typedef struct { + Bit8 index; + m6502_AddrMode adm; +} m6502_OpcodeIndex; + +/* Plotter is a function that will be called everytime a pixel + needs to be updated. The first two parameter are the x and y + values. The third parameter is the color index: + + Color Index Table + 00 black #000000 + 01 white #ffffff + 02 Red #880000 + 03 seafoam #aaffee + 04 fuscia #cc44cc + 05 green #00cc55 + 06 blue #0000aa + 07 Yellow #eeee77 + 08 tangerine #dd8855 + 09 brown #664400 + 10 salmon #ff7777 + 11 charcoal #333333 + 12 smoke #777777 + 13 lime #aaff66 + 14 light blue #0088ff + 15 gray #bbbbbb + + The plotter state variable of the machine gets passed as the forth + parameter. You can use this parameter to store state information. + +*/ +typedef void (*m6502_Plotter) (Bit8, Bit8, Bit8, void*); + +struct machine_6502 { + BOOL codeCompiledOK; + Bit8 regA; + Bit8 regX; + Bit8 regY; + Bit8 regP; + Bit16 regPC; /* A pair of 8 bit registers */ + Bit16 regSP; + Bit16 defaultCodePC; + Bit8 memory[MEM_64K]; + BOOL runForever; + int labelPtr; + BOOL codeRunning; + int myInterval; + m6502_Opcodes opcodes[NUM_OPCODES]; + int screen[32][32]; + int codeLen; + m6502_OpcodeIndex opcache[0xff]; + m6502_Plotter plot; + void *plotterState; +}; + +/* build6502() - Creates an instance of the 6502 machine */ +machine_6502 *m6502_build(void); + +/* destroy6502() - compile the file and exectue it until the program + is finished */ +void m6502_destroy6502(machine_6502 *machine); + +/* eval_file() - Compiles and runs a file until the program is + finished */ +void m6502_eval_file(machine_6502 *machine, const char *filename, + m6502_Plotter plot, void *plotterState); + +/* start_eval_file() - Compile the file and execute the first + instruction */ +void m6502_start_eval_file(machine_6502 *machine, const char *filename, + m6502_Plotter plot, void *plotterState); + +/* XXX +void m6502_start_eval_binary(machine_6502 *machine, Bit8 *program, + unsigned int proglen, + Plotter plot, void *plotterState); +*/ + +void m6502_start_eval_string(machine_6502 *machine, const char *code, + m6502_Plotter plot, void *plotterState); + +/* next_eval() - Execute the next insno of machine instructions */ +void m6502_next_eval(machine_6502 *machine, int insno); + +/* hexDump() - Dumps memory to output */ +void m6502_hexDump(machine_6502 *machine, Bit16 start, + Bit16 numbytes, FILE *output); + +/* Disassemble() - Prints the assembly code for the program currently + loaded in memory.*/ +void m6502_disassemble(machine_6502 *machine, FILE *output); + +/* trace() - Prints to output the current value of registers, the + current nmemonic, memory address and value. */ +void m6502_trace(machine_6502 *machine, FILE *output); + +/* save_program() - Writes a binary file of the program loaded in + memory. */ +/* XXX +void save_program(machine_6502 *machine, const char *filename); +*/ +#endif /* __ASM6502_H__ */ |