diff options
Diffstat (limited to 'blastem.c')
| -rw-r--r-- | blastem.c | 257 |
1 files changed, 249 insertions, 8 deletions
@@ -6,6 +6,7 @@ #include "blastem.h" #include <stdio.h> #include <stdlib.h> +#include <string.h> #define CARTRIDGE_WORDS 0x200000 #define RAM_WORDS 32 * 1024 @@ -585,6 +586,232 @@ m68k_context * io_read_w(uint32_t location, m68k_context * context) return context; } +typedef struct bp_def { + struct bp_def * next; + uint32_t address; + uint32_t index; +} bp_def; + +bp_def * breakpoints = NULL; +uint32_t bp_index = 0; + +bp_def ** find_breakpoint(bp_def ** cur, uint32_t address) +{ + while (*cur) { + if ((*cur)->address == address) { + break; + } + cur = &((*cur)->next); + } + return cur; +} + +bp_def ** find_breakpoint_idx(bp_def ** cur, uint32_t index) +{ + while (*cur) { + if ((*cur)->index == index) { + break; + } + cur = &((*cur)->next); + } + return cur; +} + +char * find_param(char * buf) +{ + for (; *buf; buf++) { + if (*buf == ' ') { + if (*(buf+1)) { + return buf+1; + } + } + } + return NULL; +} + +void strip_nl(char * buf) +{ + for(; *buf; buf++) { + if (*buf == '\n') { + *buf = 0; + return; + } + } +} + +m68k_context * debugger(m68k_context * context, uint32_t address) +{ + static char last_cmd[1024]; + char input_buf[1024]; + static uint32_t branch_t; + static uint32_t branch_f; + m68kinst inst; + //probably not necessary, but let's play it safe + address &= 0xFFFFFF; + if (address == branch_t) { + bp_def ** f_bp = find_breakpoint(&breakpoints, branch_f); + if (!*f_bp) { + remove_breakpoint(context, branch_f); + } + branch_t = branch_f = 0; + } else if(address == branch_f) { + bp_def ** t_bp = find_breakpoint(&breakpoints, branch_t); + if (!*t_bp) { + remove_breakpoint(context, branch_t); + } + branch_t = branch_f = 0; + } + //Check if this is a user set breakpoint, or just a temporary one + bp_def ** this_bp = find_breakpoint(&breakpoints, address); + if (*this_bp) { + printf("Breakpoint %d hit\n", (*this_bp)->index); + } else { + remove_breakpoint(context, address); + } + uint16_t * pc; + if (address < 0x400000) { + pc = cart + address/2; + } else if(address > 0xE00000) { + pc = ram + (address & 0xFFFF)/2; + } else { + fprintf(stderr, "Entered debugger at address %X\n", address); + exit(1); + } + uint16_t * after_pc = m68k_decode(pc, &inst, address); + m68k_disasm(&inst, input_buf); + printf("%X: %s\n", address, input_buf); + uint32_t after = address + (after_pc-pc)*2; + int debugging = 1; + while (debugging) { + fputs(">", stdout); + if (!fgets(input_buf, sizeof(input_buf), stdin)) { + fputs("fgets failed", stderr); + break; + } + strip_nl(input_buf); + //hitting enter repeats last command + if (input_buf[0]) { + strcpy(last_cmd, input_buf); + } else { + strcpy(input_buf, last_cmd); + } + char * param; + char format[8]; + uint32_t value; + bp_def * new_bp; + switch(input_buf[0]) + { + case 'c': + puts("Continuing"); + debugging = 0; + break; + case 'b': + param = find_param(input_buf); + if (!param) { + fputs("b command requires a parameter\n", stderr); + break; + } + value = strtol(param, NULL, 16); + insert_breakpoint(context, value, (uint8_t *)debugger); + new_bp = malloc(sizeof(bp_def)); + new_bp->next = breakpoints; + new_bp->address = value; + new_bp->index = bp_index++; + breakpoints = new_bp; + printf("Breakpoint %d set at %X\n", new_bp->index, value); + break; + case 'a': + param = find_param(input_buf); + if (!param) { + fputs("a command requires a parameter\n", stderr); + break; + } + value = strtol(param, NULL, 16); + insert_breakpoint(context, value, (uint8_t *)debugger); + debugging = 0; + break; + case 'd': + param = find_param(input_buf); + if (!param) { + fputs("b command requires a parameter\n", stderr); + break; + } + value = atoi(param); + this_bp = find_breakpoint_idx(&breakpoints, value); + if (!*this_bp) { + fprintf(stderr, "Breakpoint %d does not exist\n", value); + break; + } + new_bp = *this_bp; + *this_bp = (*this_bp)->next; + free(new_bp); + break; + case 'p': + strcpy(format, "%s: %d\n"); + if (input_buf[1] == '/') { + switch (input_buf[2]) + { + case 'x': + case 'X': + case 'd': + case 'c': + format[5] = input_buf[2]; + break; + default: + fprintf(stderr, "Unrecognized format character: %c\n", input_buf[2]); + } + } + param = find_param(input_buf); + if (!param) { + fputs("p command requires a parameter\n", stderr); + break; + } + if (param[0] == 'd' && param[1] >= '0' && param[1] <= '7') { + value = context->dregs[param[1]-'0']; + } else if (param[0] == 'a' && param[1] >= '0' && param[1] <= '7') { + value = context->aregs[param[1]-'0']; + } else if (param[0] == 'S' && param[1] == 'R') { + value = (context->status << 8); + for (int flag = 0; flag < 5; flag++) { + value |= context->flags[flag] << (4-flag); + } + } else if (param[0] == '0' && param[1] == 'x') { + uint32_t p_addr = strtol(param+2, NULL, 16); + value = read_dma_value(p_addr/2); + } else { + fprintf(stderr, "Unrecognized parameter to p: %s\n", param); + break; + } + printf(format, param, value); + break; + case 'n': + //TODO: Deal with jmp, dbcc, rtr and rte + if (inst.op == M68K_RTS) { + after = (read_dma_value(context->aregs[7]/2) << 16) | read_dma_value(context->aregs[7]/2 + 1); + } else if(inst.op == M68K_BCC && inst.extra.cond != COND_FALSE) { + if (inst.extra.cond = COND_TRUE) { + after = inst.address + 2 + inst.src.params.immed; + } else { + branch_f = after; + branch_t = inst.address + 2 + inst.src.params.immed; + insert_breakpoint(context, branch_t, (uint8_t *)debugger); + } + } + insert_breakpoint(context, after, (uint8_t *)debugger); + debugging = 0; + break; + case 'q': + puts("Quitting"); + exit(0); + break; + default: + fprintf(stderr, "Unrecognized debugger command %s\n", input_buf); + break; + } + } + return context; +} + int main(int argc, char ** argv) { if (argc < 2) { @@ -595,16 +822,27 @@ int main(int argc, char ** argv) fprintf(stderr, "Failed to open %s for reading\n", argv[1]); return 1; } - int width = 320; - int height = 240; - if (argc > 2) { - width = atoi(argv[2]); - if (argc > 3) { - height = atoi(argv[3]); - } else { - height = (width/320) * 240; + int width = -1; + int height = -1; + int debug = 0; + for (int i = 2; i < argc; i++) { + if (argv[i][0] == '-') { + switch(argv[i][1]) { + case 'd': + debug = 1; + break; + default: + fprintf(stderr, "Unrecognized switch %s\n", argv[i]); + return 1; + } + } else if (width < 0) { + width = atoi(argv[i]); + } else if (height < 0) { + height = atoi(argv[i]); } } + width = width < 320 ? 320 : width; + height = height < 240 ? (width/320) * 240 : height; render_init(width, height); x86_68k_options opts; @@ -629,6 +867,9 @@ int main(int argc, char ** argv) translate_m68k_stream(address, &context);*/ address = cart[2] << 16 | cart[3]; translate_m68k_stream(address, &context); + if (debug) { + insert_breakpoint(&context, address, (uint8_t *)debugger); + } m68k_reset(&context); return 0; } |