This is a work in progress
These identifiers are used by Apple to fully identify and validate your Mac, without them you can't login with iCloud/iMessage/FaceTime and are stored inside the NVRAM volume at the Fsys store and MLB sector.
| Identifier: | Definition: |
|---|---|
| SSN | System Serial Number |
| HWC | Hardware Code |
| SON | System/Sales Order Number |
| LBSN/MLB SN | Main Logic Board Serial Number |
| BD | Logic Board Build Date |
| UUID | Universally Unique Identifier |
Main Logic Board Serial Number (MLB SN) and Build Date (BD):
This two Mac Pro identifiers are stored at the last bytes of the BootROM. They have the same format, size and are stored at the same address on every Mac Pro 2009 to 2012. On a 2008, they're at the end of the BootROM too, but MP31 has only half of the SPI flash size of a 2009/2010/2012. On a 2013, it's at the last bytes too, but the SPI Flash has the double size of a 2009/2010/2012.
You can extract the complete MLB sector with UEFITool, it's the last RAW section of the 1BA0062E-C779-4582-8566-336AE8F78F09 GUID.
How-to check MP5,1 MainLogicBoardSerialNumber and BuildDate:
On the MP5,1 Logic Board:
MLB SN is printed on a black/white label near the AirPort connector and the male CPU tray connector. It's usually to the left of the male CPU tray connector, but can be placed to the right too.
Example picture:
In the picture above, MLB SN is J5911053Q1LTC and the part number/SKU of this logic board is 630-9399. BD is not present on the labels of the logic board.
On the MP5,1 BootROM:
MLB SN and BD don't have ASCII labels showing their location in the BootROM, they have fixed positions and are used to calculate the Mac Pro Hardware UUID:
| Identifier: | Start address: | End address: |
|---|---|---|
| LBSN | 0x3FFF08 | 0x3FFF14 |
| BD | 0x3FFF50 | 0x3FFF5B |
Example picture:
In the picture above, MLB SN (cyan) is J5911053Q1LTC and BD (yellow) is 090216090216. It's easy to find the MLB SN and BD position, it's at the very end of the BootROM.
The alphanumerical char (p) at the end of the BD, position 0x3FFF5C, it's a delimiter and can be alphanumerical char (7) too. Sometimes Apple uses this, sometimes not - seems to be a checksum thing.
About the BD:
Build date it's the date that the logic board was made and has this unusual format:
YYMMDDYYMMDD
While you don't need the exact real date of manufacture from your Mac Pro to validate it with Apple, a correctly formatted date no later than the date you can get from the SSN will work and must be present at the LBSN_BD sector, but try your best to use a near enough date or Messages will not authenticate. It's a salt needed when creating UUID.
One trick that I use is to decode the SSN manually, or with internet serial number decoders, and use that date. It's not exactly correct, at best it's the same week that the backplane was made, but near enough and probably will do.
Btw, this some times needs little adjusts to validate Messages correctly.
About the part number/SKU:
Part number/SKU is only of interest if somehow your BootROM misses the SON, then you replace it with the part number/SKU to create a valid Hardware UUID. A symptom of missing SON is rejected logins with iCloud/iMessage/FaceTime.
I prefer to use the Mac Pro part numbers/SKU in the BootROMs I reconstructed, like Apple do for retail Mac Pros, but you can use the logic board part number/SKU too.
Apple changes a little the part number/SKU of the Mac Pros to use it as SON on the BootROM. This happens with 4,1, 5,1 and 6,1 models but not with the 3,1 (has only one retail model and another one made specifically for the EDU channel, the single processor one).
Examples I've found:
| Mac Pro Model: | Mac Pro Part Number: | SON: |
|---|---|---|
| MP31 | MA970LL/A | MA970LL/A |
| MP41 | MB535BZ/A | RMB535BZ/ |
| MP41 | MB535LL/A | FMB535LL/ |
| MP41 | MB535LL/A | GMB535LL/ |
| MP41 | MB871LL/A | FMB871LL/ |
| MP41 | MB871LL/A | 0MB871LL/ |
| MP51 | MC250LL/A | RMC250LL/ |
| MP51 | MC561LL/A | RMC561LL/ |
| MP51 | MD770LL/A | D770LL/A |
| MP51 | MD772LL/A | D772LL/A |
| MP61 | ME253LL/A | ME253B/ |
The Hardware UUID calculated with the logic board part number/SKU will validate with Apple.
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