source/src/vm/sc3000/memory.cpp

   1 /*
   2         SEGA SC-3000 Emulator 'eSC-3000'
   3
   4         Author : Takeda.Toshiya
   5         Date   : 2010.08.17-
   6
   7         [ memory ]
   8 */
   9
  10 #include "memory.h"
  11
  12 namespace SC3000 {
  13
  14 #define SET_BANK(s, e, w, r) { \
  15         int sb = (s) >> 12, eb = (e) >> 12; \
  16         for(int i = sb; i <= eb; i++) { \
  17                 if((w) == wdmy) { \
  18                         wbank[i] = wdmy; \
  19                 } else { \
  20                         wbank[i] = (w) + 0x1000 * (i - sb); \
  21                 } \
  22                 if((r) == rdmy) { \
  23                         rbank[i] = rdmy; \
  24                 } else { \
  25                         rbank[i] = (r) + 0x1000 * (i - sb); \
  26                 } \
  27         } \
  28 }
  29
  30 void MEMORY::initialize()
  31 {
  32 //      memset(cart, 0xff, sizeof(cart));
  33         memset(ipl, 0xff, sizeof(ipl));
  34         memset(ram, 0, sizeof(ram));
  35         memset(rdmy, 0xff, sizeof(rdmy));
  36
  37         // load ipl
  38         FILEIO* fio = new FILEIO();
  39         if(fio->Fopen(create_local_path(_T("SF7000.ROM")), FILEIO_READ_BINARY)) {
  40                 fio->Fread(ipl, sizeof(ipl), 1);
  41                 fio->Fclose();
  42         }
  43         delete fio;
  44
  45         // set memory map
  46         close_cart();
  47 }
  48
  49 void MEMORY::write_data8(uint32_t addr, uint32_t data)
  50 {
  51         addr &= 0xffff;
  52         if(addr >= 0xfffd) {
  53                 if(bank[addr - 0xfffd] != 0xff) {
  54                         bank[addr - 0xfffd] = data;
  55                         update_bank();
  56                 }
  57         }
  58         wbank[addr >> 12][addr & 0xfff] = data;
  59 }
  60
  61 uint32_t MEMORY::read_data8(uint32_t addr)
  62 {
  63         addr &= 0xffff;
  64         return rbank[addr >> 12][addr & 0xfff];
  65 }
  66
  67 void MEMORY::write_signal(int id, uint32_t data, uint32_t mask)
  68 {
  69         if(id == SIG_MEMORY_SEL) {
  70                 // from PIO-P6
  71                 ram_selected = ((data & mask) != 0);
  72                 update_bank();
  73         }
  74 }
  75
  76 void MEMORY::open_cart(const _TCHAR* file_path)
  77 {
  78         FILEIO* fio = new FILEIO();
  79
  80         if(fio->Fopen(file_path, FILEIO_READ_BINARY)) {
  81                 memset(cart, 0xff, sizeof(cart));
  82                 fio->Fread(cart, sizeof(cart), 1);
  83                 if(fio->Ftell() > 0x8000) {
  84                         // \83z\81[\83\80\96\83\90\9d(32KB+16KB) or \83\8d\83\8c\83b\83^\82Ì\8fÑ\91\9c(128KB)
  85                         bank[0] = 0;
  86                         bank[1] = 1;
  87                         bank[2] = 2;
  88                 } else {
  89                         bank[0] = bank[1] = bank[2] = 0xff;
  90                 }
  91                 fio->Fclose();
  92                 inserted = true;
  93                 ram_selected = false;
  94
  95                 // set memory map
  96                 update_bank();
  97         }
  98         delete fio;
  99 }
 100
 101 void MEMORY::close_cart()
 102 {
 103         memset(cart, 0xff, sizeof(cart));
 104         inserted = false;
 105         ram_selected = false;
 106         bank[0] = bank[1] = bank[2] = 0xff;
 107
 108         // set memory map
 109         update_bank();
 110 }
 111
 112 void MEMORY::update_bank()
 113 {
 114         if(!inserted) {
 115                 SET_BANK(0x0000, 0x1fff, ram + 0x0000, ipl);
 116                 SET_BANK(0x2000, 0x3fff, ram + 0x2000, rdmy);
 117                 SET_BANK(0x4000, 0xffff, ram + 0x4000, ram + 0x4000);
 118         } else {
 119                 if(bank[0] == 0xff) {
 120                         SET_BANK(0x0000, 0x3fff, wdmy, cart + 0x0000);
 121                 } else {
 122                         SET_BANK(0x0000, 0x3fff, wdmy, cart + 0x4000 * (bank[0] & 7));
 123                 }
 124                 if(bank[1] == 0xff) {
 125                         SET_BANK(0x4000, 0x7fff, wdmy, cart + 0x4000);
 126                 } else {
 127                         SET_BANK(0x4000, 0x7fff, wdmy, cart + 0x4000 * (bank[1] & 7));
 128                 }
 129                 if(bank[2] == 0xff) {
 130                         SET_BANK(0x8000, 0xbfff, ram + 0x8000, ram + 0x8000);
 131                 } else {
 132                         SET_BANK(0x8000, 0xbfff, wdmy, cart + 0x4000 * (bank[2] & 7));
 133                 }
 134                 SET_BANK(0xc000, 0xffff, ram + 0xc000, ram + 0xc000);
 135         }
 136         if(ram_selected) {
 137                 SET_BANK(0x0000, 0x3fff, ram, ram);
 138         }
 139 }
 140
 141 #define STATE_VERSION   2
 142
 143 bool MEMORY::process_state(FILEIO* state_fio, bool loading)
 144 {
 145         if(!state_fio->StateCheckUint32(STATE_VERSION)) {
 146                 return false;
 147         }
 148         if(!state_fio->StateCheckInt32(this_device_id)) {
 149                 return false;
 150         }
 151         state_fio->StateArray(ram, sizeof(ram), 1);
 152         state_fio->StateValue(inserted);
 153         state_fio->StateValue(ram_selected);
 154         state_fio->StateArray(bank, sizeof(bank), 1);
 155
 156         // post process
 157         if(loading) {
 158                 update_bank();
 159         }
 160         return true;
 161 }
 162
 163 }