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/* SPDX-License-Identifier: Unlicense
*/
#include "bus.hpp"
#include "musashi-m68k/m68k.h"
#include "utils.hpp"
#include <cassert>
#include <cstdarg>
#include <cstdbool>
#include <cstdio>
#include <cstdint>
#include <cstdlib>
unsigned char g_rom[ROM_SIZE] = {};
unsigned char g_ram[RAM_SIZE] = {};
unsigned char g_io1[IO1_SIZE] = {};
unsigned char g_io2[IO2_SIZE] = {};
std::vector<Breakpoint> code_bkpts{}, read_bkpts{}, write_bkpts{}, access_bkpts{};
static void exit_error(const char* fmt, ...)
{
va_list args;
va_start(args, fmt);
vfprintf(stderr, fmt, args);
va_end(args);
fprintf(stderr, "\n");
unsigned int pc = m68k_get_reg(NULL, M68K_REG_PPC);
char buff[100];
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];
}
UNREACHABLE;
}
static inline struct read_result memory_read(
enum bitness bitness,
unsigned int address)
{
if (is_in_range(address, ROM_START, ROM_SIZE)) {
return read_result{
memory_read_concrete(bitness, g_rom, address - ROM_START),
true,
};
} else if (is_in_range(address, RAM_START, RAM_SIZE)) {
return read_result{
memory_read_concrete(bitness, g_ram, address - RAM_START),
true,
};
} else if (is_in_range(address, IO1_START, IO1_SIZE)) {
return read_result{
memory_read_concrete(bitness, g_io1, address - IO1_START),
true,
};
} else if (is_in_range(address, IO2_START, IO2_SIZE)) {
return read_result{
memory_read_concrete(bitness, g_io2, address - IO2_START),
true,
};
}
return 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;
break;
case BITNESS_16:
base[address + 0] = (value >> 8) & 0xff;
base[address + 1] = value & 0xff;
break;
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;
break;
}
}
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;
}
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);
}
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