[Etherboot-developers] 3C905CX-TXM flashing with cromutil hangs

[Robb M. <ma...@ac...>]

I just checked the AMD site for info on the flash you mentioned (AMD
AM29F002BT-70JC) - the datasheet can be obtained here:
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/2152
7d.pdf

Two things to note:
- The part is a 256KB x 8 part, with a "top boot-sector". This means that
the top page of the flash is normally visible on release of system reset.
Since you mention your card is located at 0xD800, it is likely to have no
larger than a 32KB active image, but could have either 16KB or 8KB. If 3-Com
parts support paging the flash in a "windowed" interface, and your update
utility supports this, the utility may have written your code into a page at
the 'bottom' of the flash, instead of the top.

- This part supports sector level write/erase protection. If 3-Com
implemented this, you will have to pull the RESET line up to Vid (+5V from
the datasheet) to (temporarily) unlock write protected pages in order to
perform the update. It is possible they tied a GPIO to the reset line to
allow their update utility to override the sector lock. (There are other
ways to override the lock, but they are only suitable for a manufacturing /
test environment, and don't apply here).

I think the second is the most likely of the two scenarios.

Good luck,
Robb Main.