MechaCon
MechaCon is short for Mechanics Controller. This chip is the security ic of the PlayStation 2 that implements game disk security, Magic Gate and KELF file decryption.
There are two known main variants of it.
The earlier one is based on SPC 9700 and used till GH-022. Chip name starts with "CXP10". Older versions come in a QFP package, newer versions in a BGA package.
The newer one is ARM based, codenamed "Dragon", and used from GH-023 (SCPH-5000X) onwards. Chip name starts with "CXR7". All versions come in a BGA package. Besides this, "Dragon" also includes the functions that were fulfilled by the separate SysCon chip on earlier boards up to GH-022, as well as the RTC+EEPROM chip, that was separate on earlier boards (or dedicated EEPROM and RTC chips on even earlier boards).
The chip contains (Dragon) or is connected to (on earlier boards) an 512 word eeprom. The content is different between the two main revisions.
SPC
Hardware revisions
- CXP101064 (only used on early GH-001 boards)
- CXP102064
- CXP103049 (BGA case, used in F and G-chassis)
Firmware revisions
Firmware comes in an OTP or mask ROM inside MechaCon.
TODO
Dragon
Hardware revisions
- CXR706F080 (has a flash ROM for firmware; used for engineering, not used in retail consoles)
- CXR706080 (used in H, I and J chassis SCPH-5XXXX consoles as well as in PSX)
- CXR716080 (used in K, L and M slim chassis SCPH-70XXX, SCPH-75XXX and SCPH-77XXX consoles)
- CXR726080 (used in N, P and R slim chassis SCPH-79XXX and SCPH-9XXXX consoles)
Firmware revisions
Firmware comes in an OTP or mask ROM inside MechaCon, except in CXR706F080, which has a reprogrammable flash ROM. Early versions have a tendency to crash on badly readable discs (e.g. badly burned/low quality DVD-R discs or scratched originals), overvolting the focus/tracking coils of the laser and killing them and also the driver IC in the process. Several fixes have been developed by the community to adress this issue with varying success.
TODO
EEPROM layout
Start (word) | End (word) | Size (byte) | Offset in file | Description |
---|---|---|---|---|
0 | 48 | 96 | 0x0 | |
48 | 90 | 84 | 0x60 | |
96 | 128 | 64 | 0xC0 | |
128 | 150 | 44 | 0x100 | |
160 | 190 | 60 | 0x140 | |
192 | 198 | 12 | 0x180 | Region params (only slim) |
204 | 208 | 8 | 0x198 | MAC address |
211 | 216 | 10 | 0x1A6 | wake up time |
216 | 225 | 18 | 0x1B0 | model number |
227 | 232 | 10 | 0x1C6 | Region code key seed |
232 | 237 | 10 | 0x1D0 | Region code ciphertext |
240 | 245 | 10 | 0x1E0 | iLink id |
245 | 248 | 6 | 0x1EA | (used by scmd 3, subcmd 48 and 49) |
248 | 253 | 10 | 0x1F0 | Console id |
253 | 256 | 6 | 0x1FA | (used by scmd 3, subcmd 48 and 49) |
256 | 312 | 112 | 0x200 | config 2 |
312 | 344 | 64 | 0x270 | config 0 |
344 | 400 | 112 | 0x2B0 | config 1 |
400 | 512 | 224 | 0x320 | Rom patches ciphertext |
Region code
Decryption
int getRegionFlags() { // read kek uint8_t key508[8]; ksGetKey(key508, 508); // read saved seed from eeprom uint8_t keyseed[10]; eepromRead(227, sizeof(keyseed), keyseed); // read encrypted region from eeprom uint8_t ciphertext[10]; eepromRead(232, sizeof(ciphertext), ciphertext); // generate key uint8_t key[8]; desEncrypt(key508, keyseed, key); // decrypt ciphertext uint8_t plaintext[8]; desDecrypt(key, ciphertext, plaintext); uint16_t crc = *(uint16_t *) plaintext; crc += *(uint16_t *) &plaintext[2]; crc += *(uint16_t *) &plaintext[4]; // check checksum if (crc == *(uint16_t *) &plaintext[6]) return *(uint32_t *) plaintext; retrun 0; }
Bits
Bit | Description |
---|---|
0 | Japan |
1 | USA |
2 | Europe |
3 | Oceania |
4 | Asia |
5 | Russia |
6 | China |
7 | Mexico |
16 | Development (changes MagicGate keys) |
17 | Retail MagicGate keys on Development, bypass BootCertify |
18 | Arcade (changes MagicGate keys) |
19 | Prototype? (changes MagicGate keys) |
20 | ? (dvd related) |
Rom patch
Decryption
bool readAndDecryptRomPatch() { // read the patch's first half uint8_t patches[0xDE]; eepromRead(400, 0x70, patches); // check if the -1th byte is 0 (sum is not checked) if (patches[0x6E]) return false; // read the patch's second half eepromRead(456, 0x70, &patches[0x6E]); // check if the -1th byte is 0 (sum is not checked) if (patches[0xDC]) return false; // read encryption key uint8_t key504[8]; ksGetKey(key504, 504); // decrypt the patch using DES-ECB for (int i = 0; i < 0xD8; i += 8) desDecrypt(key504, &patches[i], &patches[i]); // check sum uint32_t sum = *(uint32_t *)patches; sum += *(uint32_t *)&patches[4]; sum += *(uint32_t *)&patches[8]; sum += *(uint32_t *)&patches[12]; if (*(uint32_t *) &patches[0xD8] == ~sum) return false; return true; }
Content
The patch can contain up to 4 patches.
addressX = The address where to apply the patch
valueX = The data that's written there
svc_addressX = The address where SVC X instruction jumps to.
payload = Arbitrary, could be code or data as well.
Offset | Size | Name |
---|---|---|
0x00 | 0x04 | address0 |
0x04 | 0x04 | address1 |
0x08 | 0x04 | address2 |
0x0C | 0x04 | address3 |
0x10 | 0x04 | value0 |
0x14 | 0x04 | value1 |
0x18 | 0x04 | value2 |
0x1C | 0x04 | value3 |
0x20 | 0x04 | svc_address0 |
0x24 | 0x04 | svc_address1 |
0x28 | 0x04 | svc_address2 |
0x2C | 0x04 | svc_address3 |
0x30 | 0xA8 | payload |
0xD8 | 0x04 | crc |