A1418 820-00431-A BIOS - serial # location?

[mon2]

Hi.

1) Is a bios dump available for the A1418 820-00431-A logic board without password?

2) For this dump, where is the serial # of the logic board stored? Can this serial # be changed?

Have not worked with a flash dump yet but wish to source a WSON adapter so we can change the serial # to match the laser engraved iMAC base.

Our WSON to PDIP adapter is in transit using the slow shipping method from offshore. Will see if Digikey or Mouser offers this adapter.

Appreciate any advice. Thanks.

[SMDFlea]

Re: A1418 820-00431-A BIOS - serial # location?

The answer to both questions is Yes .

When you change the serial number you need to change fsys checksum as well.You also need to clean the ME firmware as the bios has been booted on another machine already.
These 2 videos by @piernov cover both areas in detail

https://www.youtube.com/watch?v=poA8HByYqTM
https://www.youtube.com/watch?v=exfG5Iywmjk

The attached bios is untested by me, i got it from the rossmann forums.

[mon2]

Re: A1418 820-00431-A BIOS - serial # location?

Thank you so much! Excellent video (watched the first one). Learned a lot.

We also placed an order for the SAM connector programmers which effectively allow for the in-system programming of the SPI flash. That should be here by mid-late next week from Asia.

Weird on how that can work wrt to the Vcc of the SPI flash. I would have thought that you MUST assert a RESET on the CPU / logic board to tri-state the flash interface lines so that the external SPI bus master can read/write the flash. Yet see many programmers that apply +3v3 onto the flash device itself.

Would that not start to power the +3v3 rail of the logic board but not really succeed as there is limited USB power that can be used as a source?

Anyways, will research the topic some more. Interesting that their tools must be performing the CRC32 calculations on the fly. More homework to do upon arrival.

Thanks again!!

[SMDFlea]

Re: A1418 820-00431-A BIOS - serial # location?

I think i know which tool youre talking about youve mentioned it before, i looked it up, it had the software from AsProgrammer which is a free alternative to the cheapo CH341A programmer. This might help you but ive never used it, - https://github.com/sadponyguerillabo...EFI-Patcher-V2 .https://github.com/sadponyguerillaboy

EDIT: https://github.com/sadponyguerillabo...le-EFI-Patcher

[interpc]

Re: A1418 820-00431-A BIOS - serial # location?

The answer to both questions is Yes .

When you change the serial number you need to change fsys checksum as well.You also need to clean the ME firmware as the bios has been booted on another machine already.
These 2 videos by @piernov cover both areas in detail

https://www.youtube.com/watch?v=poA8HByYqTM
https://www.youtube.com/watch?v=exfG5Iywmjk

The attached bios is untested by me, i got it from the rossmann forums.

Works!!