EEPROM - Revision history

KaosEngineer: /* The HMAC SHA1 Hash */ It's not the HMAC HDD Key but the HMAC SHA1 Hash computed across the first 48 bytes which includes the RC4 encrypted HDD Key, etc.

2020-08-20T01:22:37Z

‎The HMAC SHA1 Hash: It's not the HMAC HDD Key but the HMAC SHA1 Hash computed across the first 48 bytes which includes the RC4 encrypted HDD Key, etc.

JayFoxRox: Added VGA port dumping method

2020-08-12T21:33:37Z

Added VGA port dumping method

Ernegien: /* Checksum Algorithm */

2020-06-19T06:25:25Z

‎Checksum Algorithm

Ernegien: /* Checksum Algorithm */

2020-06-19T06:23:32Z

‎Checksum Algorithm

Dracc: /* Contents */

2019-06-12T16:07:25Z

‎Contents

Dracc: Add Audio settings as described by LukeUsher

2019-06-12T16:06:33Z

Add Audio settings as described by LukeUsher

JayFoxRox: Add video setting information by LukeUsher and wutno

2019-06-12T09:31:57Z

Add video setting information by LukeUsher and wutno

Dracc: Video settings "Normal" confirmed

2019-06-12T07:00:09Z

Video settings "Normal" confirmed

JayFoxRox: Refactor

2019-05-05T19:28:09Z

Refactor

Show changes

JayFoxRox: Make checksum code more readable

2019-05-05T19:01:50Z

Make checksum code more readable

@@ Line 223: / Line 223: @@
 or [https://www.totalphase.com/products/aardvark-i2cspi/ here]), build an [https://www.youtube.com/watch?v=UcK6nKyKGVQ I2C-Serial cable], or use a device like a RaspberryPi which has an I2C interface. Connect SDA/SCL/ground to the LPC pinout on the board. See [https://github.com/grimdoomer/PiPROM here] for pinout information. Then use the corresponding software to read/write the EEPROM.
-== The HMAC HDD Key ==
+== The HMAC SHA1 Hash ==
-The HMAC HDD Key is generated{{FIXME|reason=Stored? Derived? At factory?}} out of the first 48 bytes{{FIXME|reason=..first 48 EEPROM bytes? Encrypted / Decrypted?}}. This section has been identified clearly{{FIXME|reason=What does this mean?}}.
+The HMAC SHA1 Hash is generated{{FIXME|reason=Stored? Derived? At factory?}} out of the first 48 bytes{{FIXME|reason=..first 48 EEPROM bytes? Encrypted / Decrypted?}}. This section has been identified clearly{{FIXME|reason=What does this mean?}}.
 == Checksum Algorithm ==

@@ Line 299: / Line 299: @@
 * [https://web.archive.org/web/20040604013125/http://console-dev.com:80/eeprom.htm Information about EEPROM contents]
-* [https://github.com/grimdoomer/PiPROM Read/Write an original Xbox EEPROM chip with a Raspberry Pi]
+* [https://github.com/grimdoomer/PiPROM Read/Write an original Xbox EEPROM chip using a Raspberry Pi]
 * [https://www.youtube.com/watch?v=UcK6nKyKGVQ How To Make Xbox EEPROM Reader / Write (Video)]
 * [https://www.youtube.com/watch?v=uzrljlHDr9w How To Extract Xbox EEPROM Easy (Video)]

@@ Line 262: / Line 262: @@
           free(CRC_Data);
-          return *(uint32_t*)&checksum;
+          return *(uint32_t*)&crc;
+  }
 </pre>

@@ Line 257: / Line 257: @@
+                  }
                   CRCPosVal &= 0xFF00;
-                  crc[i] = (unsigned char) (CRCPosVal << 8);
+                  crc[i] = (unsigned char) (CRCPosVal >> 8);
+          }

@@ Line 131: / Line 131: @@
 | 0x9B
 | Audio Settings
 * 0x00000000 = Stereo
 * 0x00000001 = Mono
 * 0x00000002 = Surround
 * 0x00010000 = Enable AC3
 * 0x00020000 = Enable DTS

@@ Line 118: / Line 118: @@
 | 0x97
 | Video Settings
-Offset 0x96:
+* 0x00010000 = Widescreen{{FIXME|reason=What happens if Widescreen and letterbox are enabled at the same time? Can this happen?}}
-* 0x00=Normal
+* 0x00100000 = Letterbox{{FIXME|reason=What happens if Widescreen and letterbox are enabled at the same time? Can this happen?}}
-* 0xB0=Widescreen
-* 0xB4=Letterbox
+* 0x00400000 = 60Hz{{FIXME|reason=Unconfirmed; Also, what happens if both refresh rates are disabled?}}
 |-
 | 0x98

@@ Line 332: / Line 332: @@
    * Rewritten to ANSI C by David Pye (dmp@davidmpye.dyndns.org)
+   *
-   * Thanks! */
+   * Adapted for XboxDevWiki
-  void EepromCRC(unsigned char *crc, unsigned char *data, long dataLen) {
+  */
-         unsigned char* CRC_Data = (unsigned char *)malloc(dataLen+4);
+  uint32_t EepromCRC(unsigned char *data, long dataLen) {
-          int pos=0;
-          memset(crc,0x00,4);
+          // Initialize result to zero
           //Circle shift input data one byte right
-          memcpy(CRC_Data + 0x01 , data, dataLen-1);
+         unsigned char* CRC_Data = (unsigned char *)malloc(dataLen + 4);
-          memcpy(CRC_Data, data + dataLen-1, 0x01);
+         memset(CRC_Data, 0x00, dataLen + 4);
-          for (pos=0; pos&lt;4; ++pos) {
+         // Calculate checksum
                   unsigned short CRCPosVal = 0xFFFF;
-                  unsigned long l;
+                  for (unsigned long l = i; l < dataLen; l += 4) {
                           CRCPosVal -= *(unsigned short*)(&amp;CRC_Data[l]);
+                  }
-                  CRCPosVal &amp;= 0xFF00;
+                  CRCPosVal &= 0xFF00;
-                  crc[pos] = (unsigned char) (CRCPosVal &gt;&gt; 8);
+                  crc[i] = (unsigned char) (CRCPosVal << 8);
+          }
           free(CRC_Data);
+  }
 </pre>