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- /* Common code between all z80 emulators
- */
-
- #include <string.h>
- #include "emul.h"
-
- static Machine m;
- static ushort traceval = 0;
-
- static uint8_t io_read(int unused, uint16_t addr)
- {
- addr &= 0xff;
- IORD fn = m.iord[addr];
- if (fn != NULL) {
- return fn();
- } else {
- fprintf(stderr, "Out of bounds I/O read: %d\n", addr);
- return 0;
- }
- }
-
- static void io_write(int unused, uint16_t addr, uint8_t val)
- {
- addr &= 0xff;
- IOWR fn = m.iowr[addr];
- if (fn != NULL) {
- fn(val);
- } else {
- fprintf(stderr, "Out of bounds I/O write: %d / %d (0x%x)\n", addr, val, val);
- }
- }
-
- uint8_t emul_mem_read(int unused, uint16_t addr)
- {
- return m.mem[addr];
- }
-
- void emul_mem_write(int unused, uint16_t addr, uint8_t val)
- {
- if (addr < m.ramstart) {
- fprintf(stderr, "Writing to ROM (%d)!\n", addr);
- emul_memdump();
- fprintf(stderr, "Press any key to continue...\n");
- while (getchar() > 0x100);
- }
- m.mem[addr] = val;
- }
-
- Machine* emul_init(char *binpath, ushort binoffset)
- {
- // initialize memory
- memset(m.mem, 0, 0x10000);
- FILE *bfp = fopen(binpath, "r");
- if (!bfp) {
- fprintf(stderr, "Can't open %s\n", binpath);
- return NULL;
- }
- int i = binoffset;
- int c = getc(bfp);
- while (c != EOF) {
- #ifdef MAX_ROMSIZE
- if (i >= MAX_ROMSIZE) {
- fprintf(stderr, "ROM image too large.\n");
- fclose(fp);
- return NULL;
- }
- #endif
- m.mem[i++] = c;
- c = getc(bfp);
- }
- fclose(bfp);
- m.ramstart = 0;
- m.minsp = 0xffff;
- m.maxix = 0;
- for (int i=0; i<0x100; i++) {
- m.iord[i] = NULL;
- m.iowr[i] = NULL;
- }
- m.pchooks_cnt = 0;
- Z80RESET(&m.cpu);
- m.cpu.memRead = emul_mem_read;
- m.cpu.memWrite = emul_mem_write;
- m.cpu.ioRead = io_read;
- m.cpu.ioWrite = io_write;
- return &m;
- }
-
- bool emul_step()
- {
- if (!m.cpu.halted) {
- Z80Execute(&m.cpu);
- ushort newsp = m.cpu.R1.wr.SP;
- if (newsp != 0 && newsp < m.minsp) {
- m.minsp = newsp;
- }
- if (m.cpu.R1.wr.IX > m.maxix) {
- m.maxix = m.cpu.R1.wr.IX;
- }
- for (int i=0; i<m.pchooks_cnt; i++) {
- if (m.cpu.PC == m.pchooks[i]) {
- m.pchookfunc(&m);
- break;
- }
- }
- return true;
- } else {
- return false;
- }
- }
-
- bool emul_steps(unsigned int steps)
- {
- while (steps) {
- if (!emul_step()) {
- return false;
- }
- steps--;
- }
- return true;
- }
-
- void emul_loop()
- {
- while (emul_step());
- }
-
- void emul_trace(ushort addr)
- {
- ushort newval = m.mem[addr+1] << 8 | m.mem[addr];
- if (newval != traceval) {
- traceval = newval;
- fprintf(stderr, "trace: %04x PC: %04x\n", traceval, m.cpu.PC);
- }
- }
-
- void emul_memdump()
- {
- fprintf(stderr, "Dumping memory to memdump. PC %04x\n", m.cpu.PC);
- FILE *fp = fopen("memdump", "w");
- fwrite(m.mem, 0x10000, 1, fp);
- fclose(fp);
- }
-
- void emul_debugstr(char *s)
- {
- sprintf(s, "SP %04x (%04x) IX %04x (%04x)",
- m.cpu.R1.wr.SP, m.minsp, m.cpu.R1.wr.IX, m.maxix);
- }
-
- void emul_printdebug()
- {
- fprintf(stderr, "Min SP: %04x\n", m.minsp);
- fprintf(stderr, "Max IX: %04x\n", m.maxix);
- }
-
- byte iord_noop() { return 0; }
- void iowr_noop(byte val) {}
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