Mercurial > vba-linux

     1 #include <cstring>

     2 

     3 #include "GBA.h" // for SAVE_GAME_VERSION_3

     4 #include "EEprom.h"

     5 #include "../common/System.h"

     6 #include "../common/Util.h"

     7 

     8 extern int32 cpuDmaCount;

     9 

    10 int32 eepromMode    = EEPROM_IDLE;

    11 int32 eepromByte    = 0;

    12 int32 eepromBits    = 0;

    13 int32 eepromAddress = 0;

    14 u8    eepromData[0x2000];

    15 u8    eepromBuffer[16];

    16 bool8 eepromInUse = false;

    17 int32 eepromSize  = 512;

    18 

    19 variable_desc eepromSaveData[] = {

    20 	{ &eepromMode,		sizeof(int32) },

    21 	{ &eepromByte,		sizeof(int32) },

    22 	{ &eepromBits,		sizeof(int32) },

    23 	{ &eepromAddress,	sizeof(int32) },

    24 	{ &eepromInUse,		sizeof(bool8) },

    25 	{ &eepromData[0],             512 },

    26 	{ &eepromBuffer[0],            16 },

    27 	{ NULL,							0 }

    28 };

    29 

    30 void eepromReset()

    31 {

    32 	eepromMode    = EEPROM_IDLE;

    33 	eepromByte    = 0;

    34 	eepromBits    = 0;

    35 	eepromAddress = 0;

    36 	eepromInUse   = false;

    37 	eepromSize    = 512;

    38 }

    39 

    40 void eepromErase()

    41 {

    42 	memset(eepromData, 0, 0x2000*sizeof(u8));

    43 	eepromMode    = EEPROM_IDLE;

    44 	eepromByte    = 0;

    45 	eepromBits    = 0;

    46 	eepromAddress = 0;

    47 	memset(eepromBuffer, 0, 16*sizeof(u8));

    48 	eepromInUse = false;

    49 	eepromSize  = 512;

    50 }

    51 

    52 void eepromSaveGame(gzFile gzFile)

    53 {

    54 	utilWriteData(gzFile, eepromSaveData);

    55 	utilWriteInt(gzFile, eepromSize);

    56 	utilGzWrite(gzFile, eepromData, 0x2000);

    57 }

    58 

    59 void eepromReadGame(gzFile gzFile, int version)

    60 {

    61 	utilReadData(gzFile, eepromSaveData);

    62 	if (version >= SAVE_GAME_VERSION_3)

    63 	{

    64 		eepromSize = utilReadInt(gzFile);

    65 		utilGzRead(gzFile, eepromData, 0x2000);

    66 	}

    67 	else

    68 	{

    69 		// prior to 0.7.1, only 4K EEPROM was supported

    70 		eepromSize = 512;

    71 	}

    72 }

    73 

    74 int eepromRead(u32 /* address */)

    75 {

    76 	switch (eepromMode)

    77 	{

    78 	case EEPROM_IDLE:

    79 	case EEPROM_READADDRESS:

    80 	case EEPROM_WRITEDATA:

    81 		return 1;

    82 	case EEPROM_READDATA:

    83 	{

    84 		eepromBits++;

    85 		if (eepromBits == 4)

    86 		{

    87 			eepromMode = EEPROM_READDATA2;

    88 			eepromBits = 0;

    89 			eepromByte = 0;

    90 		}

    91 		return 0;

    92 	}

    93 	case EEPROM_READDATA2:

    94 	{

    95 		int data    = 0;

    96 		int address = eepromAddress << 3;

    97 		int mask    = 1 << (7 - (eepromBits & 7));

    98 		data = (eepromData[address+eepromByte] & mask) ? 1 : 0;

    99 		eepromBits++;

   100 		if ((eepromBits & 7) == 0)

   101 			eepromByte++;

   102 		if (eepromBits == 0x40)

   103 			eepromMode = EEPROM_IDLE;

   104 		return data;

   105 	}

   106 	default:

   107 		return 0;

   108 	}

   109 	return 1;

   110 }

   111 

   112 void eepromWrite(u32 /* address */, u8 value)

   113 {

   114 	if (cpuDmaCount == 0)

   115 		return;

   116 	int bit = value & 1;

   117 	switch (eepromMode)

   118 	{

   119 	case EEPROM_IDLE:

   120 		eepromByte = 0;

   121 		eepromBits = 1;

   122 		eepromBuffer[eepromByte] = bit;

   123 		eepromMode = EEPROM_READADDRESS;

   124 		break;

   125 	case EEPROM_READADDRESS:

   126 		eepromBuffer[eepromByte] <<= 1;

   127 		eepromBuffer[eepromByte]  |= bit;

   128 		eepromBits++;

   129 		if ((eepromBits & 7) == 0)

   130 		{

   131 			eepromByte++;

   132 		}

   133 		if (cpuDmaCount == 0x11 || cpuDmaCount == 0x51)

   134 		{

   135 			if (eepromBits == 0x11)

   136 			{

   137 				eepromInUse   = true;

   138 				eepromSize    = 0x2000;

   139 				eepromAddress = ((eepromBuffer[0] & 0x3F) << 8) |

   140 				                ((eepromBuffer[1] & 0xFF));

   141 				if (!(eepromBuffer[0] & 0x40))

   142 				{

   143 					eepromBuffer[0] = bit;

   144 					eepromBits      = 1;

   145 					eepromByte      = 0;

   146 					eepromMode      = EEPROM_WRITEDATA;

   147 				}

   148 				else

   149 				{

   150 					eepromMode = EEPROM_READDATA;

   151 					eepromByte = 0;

   152 					eepromBits = 0;

   153 				}

   154 			}

   155 		}

   156 		else

   157 		{

   158 			if (eepromBits == 9)

   159 			{

   160 				eepromInUse   = true;

   161 				eepromAddress = (eepromBuffer[0] & 0x3F);

   162 				if (!(eepromBuffer[0] & 0x40))

   163 				{

   164 					eepromBuffer[0] = bit;

   165 					eepromBits      = 1;

   166 					eepromByte      = 0;

   167 					eepromMode      = EEPROM_WRITEDATA;

   168 				}

   169 				else

   170 				{

   171 					eepromMode = EEPROM_READDATA;

   172 					eepromByte = 0;

   173 					eepromBits = 0;

   174 				}

   175 			}

   176 		}

   177 		break;

   178 	case EEPROM_READDATA:

   179 	case EEPROM_READDATA2:

   180 		// should we reset here?

   181 		eepromMode = EEPROM_IDLE;

   182 		break;

   183 	case EEPROM_WRITEDATA:

   184 		eepromBuffer[eepromByte] <<= 1;

   185 		eepromBuffer[eepromByte]  |= bit;

   186 		eepromBits++;

   187 		if ((eepromBits & 7) == 0)

   188 		{

   189 			eepromByte++;

   190 		}

   191 		if (eepromBits == 0x40)

   192 		{

   193 			eepromInUse = true;

   194 			// write data;

   195 			for (int i = 0; i < 8; i++)

   196 			{

   197 				eepromData[(eepromAddress << 3) + i] = eepromBuffer[i];

   198 			}

   199 			systemSaveUpdateCounter = SYSTEM_SAVE_UPDATED;

   200 		}

   201 		else if (eepromBits == 0x41)

   202 		{

   203 			eepromMode = EEPROM_IDLE;

   204 			eepromByte = 0;

   205 			eepromBits = 0;

   206 		}

   207 		break;

   208 	}

   209 }

   210
author	Robert McIntyre <rlm@mit.edu>
date	Sun, 04 Mar 2012 14:33:52 -0600
parents	f9f4f1b99eed
children