Sun, 28 Nov 2010 19:53:53 +0000
set up ROM loader and state storage, add basic emulator core
| src/main.c | file | annotate | diff | revisions |
1.1 diff -r 5dc2f3565377 -r 7b98c7665aae src/main.c 1.2 --- a/src/main.c Sun Nov 28 19:53:14 2010 +0000 1.3 +++ b/src/main.c Sun Nov 28 19:53:53 2010 +0000 1.4 @@ -1,45 +1,253 @@ 1.5 #include <stdio.h> 1.6 +#include <stdlib.h> 1.7 #include <stdint.h> 1.8 +#include <stdbool.h> 1.9 +#include <malloc.h> 1.10 +#include <string.h> 1.11 #include "musashi/m68k.h" 1.12 +#include "version.h" 1.13 + 1.14 +#define ROM_SIZE (32768/4) 1.15 + 1.16 +void state_done(void); 1.17 + 1.18 +void FAIL(char *err) 1.19 +{ 1.20 + state_done(); 1.21 + fprintf(stderr, "ERROR: %s\nExiting...\n", err); 1.22 + exit(EXIT_FAILURE); 1.23 +} 1.24 + 1.25 + 1.26 +struct { 1.27 + // Boot PROM can be up to 32Kbytes total size 1.28 + uint32_t rom[ROM_SIZE]; 1.29 + 1.30 + // Main system RAM 1.31 + uint32_t *ram; 1.32 + size_t ram_size; // number of RAM bytes allocated 1.33 + uint32_t ram_addr_mask; // address mask 1.34 + 1.35 + // GENERAL CONTROL REGISTER 1.36 + bool romlmap; 1.37 +} state; 1.38 + 1.39 +int state_init() 1.40 +{ 1.41 + // Free RAM if it's allocated 1.42 + if (state.ram != NULL) 1.43 + free(state.ram); 1.44 + 1.45 + // Initialise hardware registers 1.46 + state.romlmap = false; 1.47 + 1.48 + // Allocate RAM 1.49 + // TODO: make sure ram size selection is valid! 1.50 + state.ram = malloc(state.ram_size); 1.51 + if (state.ram == NULL) 1.52 + return -1; 1.53 + state.ram_addr_mask = state.ram_size - 1; 1.54 1.55 -// m68k memory 1.56 -//uint32_t rom[32768/4]; 1.57 -uint32_t ram[512*1024/4]; 1.58 + // Load ROMs 1.59 + FILE *r14c, *r15c; 1.60 + r14c = fopen("roms/14c.bin", "rb"); 1.61 + if (r14c == NULL) FAIL("unable to open roms/14c.bin"); 1.62 + r15c = fopen("roms/15c.bin", "rb"); 1.63 + if (r15c == NULL) FAIL("unable to open roms/15c.bin"); 1.64 + 1.65 + // get ROM file size 1.66 + fseek(r14c, 0, SEEK_END); 1.67 + size_t romlen = ftell(r14c); 1.68 + fseek(r14c, 0, SEEK_SET); 1.69 + fseek(r15c, 0, SEEK_END); 1.70 + size_t romlen2 = ftell(r15c); 1.71 + fseek(r15c, 0, SEEK_SET); 1.72 + if (romlen2 != romlen) FAIL("ROMs are not the same size!"); 1.73 + if ((romlen / 4) > (ROM_SIZE / 2)) FAIL("ROM 14C is too big!"); 1.74 + if ((romlen2 / 4) > (ROM_SIZE / 2)) FAIL("ROM 15C is too big!"); 1.75 + 1.76 + // sanity checks completed; load the ROMs! 1.77 + uint8_t *romdat1, *romdat2; 1.78 + romdat1 = malloc(romlen); 1.79 + romdat2 = malloc(romlen2); 1.80 + fread(romdat1, 1, romlen, r15c); 1.81 + fread(romdat2, 1, romlen2, r14c); 1.82 + 1.83 + // convert the ROM data 1.84 + for (size_t i=0; i<romlen; i+=2) { 1.85 + state.rom[i/2] = ( 1.86 + (romdat1[i+0] << 24) | 1.87 + (romdat2[i+0] << 16) | 1.88 + (romdat1[i+1] << 8) | 1.89 + (romdat2[i+1])); 1.90 + } 1.91 + 1.92 + for (int i=0; i<8; i++) 1.93 + printf("%02X %02X ", romdat1[i], romdat2[i]); 1.94 + printf("\n%08X %08X\n", state.rom[0], state.rom[1]); 1.95 + 1.96 + // free the data arrays and close the files 1.97 + free(romdat1); 1.98 + free(romdat2); 1.99 + fclose(r14c); 1.100 + fclose(r15c); 1.101 + 1.102 + return 0; 1.103 +} 1.104 + 1.105 +void state_done() 1.106 +{ 1.107 + if (state.ram != NULL) 1.108 + free(state.ram); 1.109 +} 1.110 1.111 // read m68k memory 1.112 +// TODO: refactor musashi to use stdint, and properly sized integers! 1.113 +// TODO: find a way to make musashi use function pointers instead of hard coded callbacks, maybe use a context struct too 1.114 uint32_t m68k_read_memory_32(uint32_t address) 1.115 { 1.116 - return ram[address]; 1.117 + // If ROMLMAP is set, force system to access ROM 1.118 + if (!state.romlmap) 1.119 + address |= 0x800000; 1.120 + 1.121 + if (address >= 0xC00000) { 1.122 + // I/O Registers B 1.123 + // TODO 1.124 + } else if ((address >= 0x800000) && (address <= 0xBFFFFF)) { 1.125 + // ROM access 1.126 + printf("%08X\n", state.rom[(address & (ROM_SIZE-1)) / 4]); 1.127 + return state.rom[(address & (ROM_SIZE-1)) / 4]; 1.128 + } else if ((address >= 0x400000) && (address <= 0x7FFFFF)) { 1.129 + // I/O Registers A 1.130 + // TODO 1.131 + } else if (address <= 0x3FFFFF) { 1.132 + // RAM 1.133 + return state.ram[(address & state.ram_addr_mask) / 4]; 1.134 + } 1.135 + return 0xffffffff; 1.136 } 1.137 1.138 uint32_t m68k_read_memory_16(uint32_t address) 1.139 { 1.140 - return ram[address] & 0xFFFF; 1.141 + if (address & 2) { 1.142 + return m68k_read_memory_32(address) & 0xFFFF; 1.143 + } else { 1.144 + return (m68k_read_memory_32(address) >> 16) & 0xFFFF; 1.145 + } 1.146 } 1.147 1.148 uint32_t m68k_read_memory_8(uint32_t address) 1.149 { 1.150 - return ram[address] & 0xFF; 1.151 + // If ROMLMAP is set, force system to access ROM 1.152 + if (!state.romlmap) 1.153 + address |= 0x800000; 1.154 + 1.155 + switch (address & 3) { 1.156 + case 3: return m68k_read_memory_32(address) & 0xFF; 1.157 + case 2: return (m68k_read_memory_32(address) >> 8) & 0xFF; 1.158 + case 1: return (m68k_read_memory_32(address) >> 16) & 0xFF; 1.159 + case 0: return (m68k_read_memory_32(address) >> 24) & 0xFF; 1.160 + } 1.161 + return 0xffffffff; 1.162 } 1.163 1.164 // write m68k memory 1.165 void m68k_write_memory_32(uint32_t address, uint32_t value) 1.166 { 1.167 - ram[address] = value; 1.168 + // If ROMLMAP is set, force system to access ROM 1.169 + if (!state.romlmap) 1.170 + address |= 0x800000; 1.171 + 1.172 + if (address >= 0xC00000) { 1.173 + // I/O Registers B 1.174 + // TODO 1.175 + } else if ((address >= 0x800000) && (address <= 0xBFFFFF)) { 1.176 + // ROM access 1.177 + // TODO: bus error here? can't write to rom! 1.178 + } else if ((address >= 0x400000) && (address <= 0x7FFFFF)) { 1.179 + // I/O Registers A 1.180 + // TODO 1.181 + } else if (address <= 0x3FFFFF) { 1.182 + // RAM 1.183 + state.ram[(address & state.ram_addr_mask) / 4] = value; 1.184 + } 1.185 } 1.186 1.187 void m68k_write_memory_16(uint32_t address, uint32_t value) 1.188 { 1.189 - ram[address] = (ram[address] & 0xFFFF0000) | (value & 0xFFFF); 1.190 + // If ROMLMAP is set, force system to access ROM 1.191 + if (!state.romlmap) 1.192 + address |= 0x800000; 1.193 + 1.194 + if (address >= 0xC00000) { 1.195 + // I/O Registers B 1.196 + // TODO 1.197 + } else if ((address >= 0x800000) && (address <= 0xBFFFFF)) { 1.198 + // ROM access 1.199 + // TODO: bus error here? can't write to rom! 1.200 + } else if ((address >= 0x400000) && (address <= 0x7FFFFF)) { 1.201 + // I/O Registers A 1.202 + // TODO 1.203 + } else if (address <= 0x3FFFFF) { 1.204 + // RAM 1.205 + if (address & 2) 1.206 + state.ram[(address & state.ram_addr_mask) / 4] = (state.ram[(address & state.ram_addr_mask) / 4] & 0xFFFF0000) | (value & 0xFFFF); 1.207 + else 1.208 + state.ram[(address & state.ram_addr_mask) / 4] = (state.ram[(address & state.ram_addr_mask) / 4] & 0x0000FFFF) | ((value & 0xFFFF) << 16); 1.209 + } 1.210 } 1.211 1.212 void m68k_write_memory_8(uint32_t address, uint32_t value) 1.213 { 1.214 - ram[address] = (ram[address] & 0xFFFFFF00) | (value & 0xFF); 1.215 + // If ROMLMAP is set, force system to access ROM 1.216 + if (!state.romlmap) 1.217 + address |= 0x800000; 1.218 + 1.219 + if (address >= 0xC00000) { 1.220 + // I/O Registers B 1.221 + // TODO 1.222 + } else if ((address >= 0x800000) && (address <= 0xBFFFFF)) { 1.223 + // ROM access 1.224 + // TODO: bus error here? can't write to rom! 1.225 + } else if ((address >= 0x400000) && (address <= 0x7FFFFF)) { 1.226 + // I/O Registers A 1.227 + // TODO 1.228 + } else if (address <= 0x3FFFFF) { 1.229 + // RAM 1.230 + switch (address & 3) { 1.231 + case 3: state.ram[(address & state.ram_addr_mask) / 4] = (state.ram[(address & state.ram_addr_mask) / 4] & 0xFFFFFF00) | (value & 0xFF); 1.232 + case 2: state.ram[(address & state.ram_addr_mask) / 4] = (state.ram[(address & state.ram_addr_mask) / 4] & 0xFFFF00FF) | ((value & 0xFF) << 8); 1.233 + case 1: state.ram[(address & state.ram_addr_mask) / 4] = (state.ram[(address & state.ram_addr_mask) / 4] & 0xFF00FFFF) | ((value & 0xFF) << 16); 1.234 + case 0: state.ram[(address & state.ram_addr_mask) / 4] = (state.ram[(address & state.ram_addr_mask) / 4] & 0x00FFFFFF) | ((value & 0xFF) << 24); 1.235 + } 1.236 + } 1.237 } 1.238 1.239 - 1.240 int main(void) 1.241 { 1.242 + // copyright banner 1.243 + printf("FreeBee: A Quick-and-Dirty AT&T 3B1 Emulator\n"); 1.244 + printf("Copyright (C) 2010 P. A. Pemberton.\n"); 1.245 + printf("Musashi M680x0 emulator engine developed by Karl Stenerud <kstenerud@gmail.com>\n"); 1.246 + 1.247 + // set up system state 1.248 + // 512K of RAM 1.249 + state.ram_size = 512*1024; 1.250 + state_init(); 1.251 + 1.252 + // set up musashi 1.253 + m68k_set_cpu_type(M68K_CPU_TYPE_68010); 1.254 + m68k_pulse_reset(); 1.255 + 1.256 + // set up SDL 1.257 + 1.258 + // emulation loop! 1.259 + // repeat: 1.260 + // m68k_execute() 1.261 + // m68k_set_irq() every 60ms 1.262 + m68k_execute(100000); 1.263 + 1.264 + // shut down and exit 1.265 + 1.266 return 0; 1.267 }