diff options
Diffstat (limited to 'emulator.c')
| -rw-r--r-- | emulator.c | 227 |
1 files changed, 10 insertions, 217 deletions
@@ -1,230 +1,25 @@ -#include <assert.h> -#include <stdbool.h> +#include "bus.h" + #include <stdio.h> #include <stdlib.h> #include <stdarg.h> -#include <stdint.h> #include <time.h> #include "musashi-m68k/m68k.h" -#define ROM_START (0) -#define ROM_SIZE (0x400000) -#define RAM_START (0xFF0000) -#define RAM_SIZE (0x10000) -#define IO1_START (0xA10000) -#define IO1_SIZE (0x4004) -#define IO2_START (0xC00000) -#define IO2_SIZE (0x20) - -/* Data */ -unsigned char g_rom[ROM_SIZE]; -unsigned char g_ram[RAM_SIZE]; -unsigned char g_io1[IO1_SIZE]; -unsigned char g_io2[IO2_SIZE]; +#if !defined(DEBUG_TRACE_INSTRUCTIONS) +# define DEBUG_TRACE_INSTRUCTIONS 0 +#endif -/* Exit with an error message. Use printf syntax. */ static void exit_error(char* fmt, ...) { - static int guard_val = 0; - char buff[100]; - unsigned int pc; va_list args; - - if (guard_val) - return; - else - guard_val = 1; - va_start(args, fmt); vfprintf(stderr, fmt, args); va_end(args); fprintf(stderr, "\n"); - pc = m68k_get_reg(NULL, M68K_REG_PPC); - m68k_disassemble(buff, pc, M68K_CPU_TYPE_68000); - fprintf(stderr, "%08x: %s\n", pc, buff); - exit(EXIT_FAILURE); } -static inline bool is_in_range(uint32_t value, uint32_t begin, uint32_t length) -{ - return value >= begin && value <= begin + length; -} - -enum bitness { - BITNESS_8, - BITNESS_16, - BITNESS_32, -}; - -struct read_result { - unsigned int result; - bool successful; -}; - -static inline unsigned int memory_read_concrete( - enum bitness bitness, - unsigned char const * base, - unsigned int address) -{ - switch (bitness) { - case BITNESS_8: - return base[address]; - case BITNESS_16: - return (base[address] << 8) | base[address + 1]; - case BITNESS_32: - return (base[address] << 24) | - (base[address + 1] << 16) | - (base[address + 2] << 8) | - base[address + 3]; - } - __builtin_unreachable(); -} - -static inline struct read_result memory_read( - enum bitness bitness, - unsigned int address) -{ - if (is_in_range(address, ROM_START, ROM_SIZE)) - return (struct read_result){ - memory_read_concrete(bitness, g_rom, address - ROM_START), - true, - }; - else if (is_in_range(address, RAM_START, RAM_SIZE)) - return (struct read_result){ - memory_read_concrete(bitness, g_ram, address - RAM_START), - true, - }; - else if (is_in_range(address, IO1_START, IO1_SIZE)) - return (struct read_result){ - memory_read_concrete(bitness, g_io1, address - IO1_START), - true, - }; - else if (is_in_range(address, IO2_START, IO2_SIZE)) - return (struct read_result){ - memory_read_concrete(bitness, g_io2, address - IO2_START), - true, - }; - return (struct read_result){0, false}; -} - -static inline void memory_write_concrete( - enum bitness bitness, - unsigned char * base, - unsigned int address, - unsigned int value) -{ - switch (bitness) { - case BITNESS_8: - base[address] = value & 0xff; - return; - case BITNESS_16: - base[address] = (value >> 8) & 0xff; - base[address + 1] = value & 0xff; - return; - case BITNESS_32: - base[address + 0] = (value >> 24) & 0xff; - base[address + 1] = (value >> 16) & 0xff; - base[address + 2] = (value >> 8) & 0xff; - base[address + 3] = value & 0xff; - return; - } - __builtin_unreachable(); -} - -static inline bool memory_write( - enum bitness bitness, - unsigned int address, - unsigned int value) -{ - if (is_in_range(address, ROM_START, ROM_SIZE)) { - memory_write_concrete(bitness, g_rom, address - ROM_START, value); - return true; - } else if (is_in_range(address, RAM_START, RAM_SIZE)) { - memory_write_concrete(bitness, g_ram, address - RAM_START, value); - return true; - } else if (is_in_range(address, IO1_START, IO1_SIZE)) { - memory_write_concrete(bitness, g_io1, address - IO1_START, value); - return true; - } else if (is_in_range(address, IO2_START, IO2_SIZE)) { - memory_write_concrete(bitness, g_io2, address - IO2_START, value); - return true; - } - return false; -} - -#define MASK_24(X) ((X) & (0xFF << 24)) - -unsigned int m68k_read_memory_8(unsigned int address) -{ - assert(MASK_24(address) == 0); // Just curious - const struct read_result ret = memory_read(BITNESS_8, address); - if (!ret.successful) - exit_error("Read error u8 @%08x", address); - return ret.result; -} - -unsigned int m68k_read_memory_16(unsigned int address) -{ - assert(MASK_24(address) == 0); // Just curious - const struct read_result ret = memory_read(BITNESS_16, address); - if (!ret.successful) - exit_error("Read error u16 @%08x", address); - return ret.result; -} - -unsigned int m68k_read_memory_32(unsigned int address) -{ - assert(MASK_24(address) == 0); // Just curious - const struct read_result ret = memory_read(BITNESS_32, address); - if (!ret.successful) - exit_error("Read error u32 @%08x", address); - return ret.result; -} - -unsigned int m68k_read_disassembler_16(unsigned int address) -{ - assert(MASK_24(address) == 0); // Just curious - const struct read_result ret = memory_read(BITNESS_16, address); - if (!ret.successful) - exit_error("Disasm read error u16 @0x%08x", address); - return ret.result; -} - -unsigned int m68k_read_disassembler_32(unsigned int address) -{ - assert(MASK_24(address) == 0); // Just curious - const struct read_result ret = memory_read(BITNESS_32, address); - if (!ret.successful) - exit_error("Disasm read error u32 @0x%08x", address); - return ret.result; -} - -/* Write data to RAM or a device */ -void m68k_write_memory_8(unsigned int address, unsigned int value) -{ - assert(MASK_24(address) == 0); // Just curious - const bool successful = memory_write(BITNESS_8, address, value); - if (!successful) - exit_error("Attempted to write %02x (u8) to address %08x", value&0xff, address); -} - -void m68k_write_memory_16(unsigned int address, unsigned int value) -{ - assert(MASK_24(address) == 0); // Just curious - const bool successful = memory_write(BITNESS_16, address, value); - if (!successful) - exit_error("Attempted to write %04x (u16) to address %08x", value&0xffff, address); -} - -void m68k_write_memory_32(unsigned int address, unsigned int value) -{ - assert(MASK_24(address) == 0); // Just curious - const bool successful = memory_write(BITNESS_16, address, value); - if (!successful) - exit_error("Attempted to write %08x (u32) to address %08x", value, address); -} - /* Called when the CPU pulses the RESET line */ void m68k_reset_callback(void) { @@ -256,14 +51,12 @@ static void make_hex(char* buff, unsigned int pc, unsigned int length) void m68k_instr_callback(int pc) { - if (0) + if (!DEBUG_TRACE_INSTRUCTIONS) return; - static char buff[100]; - static char buff2[100]; - static unsigned int instr_size; - - pc = m68k_get_reg(NULL, M68K_REG_PC); - instr_size = m68k_disassemble(buff, pc, M68K_CPU_TYPE_68000); + char buff[100]; + unsigned int instr_size = + m68k_disassemble(buff, pc, M68K_CPU_TYPE_68000); + char buff2[100]; make_hex(buff2, pc, instr_size); printf("E %08X: %-20s: %s\n", pc, buff2, buff); fflush(stdout); |