W29C020 - software bootblock unlock

Rainbow

I've bought DTK PRM-0080I E1 (rev. B) board - very cheap because previous owner did not know if the board works or not. It works. There's Winbond W29C020 chip installed.
I tried to flash the BIOS using UniFlash - but it failed on the first 8KB and last 8KB - obviously because both top and bottom boot block protection was enabled. But I was able to flash the BIOS OK using the old AMIFLASH that I have on my webpage - so it's now proven that it can be done. After flashing, it even left the bottom bootblock area unprotected Smile

So it must disable the protection (both top and bottom) somehow, then flash and finally enable the top block protection. Now only find a way how to reverse it...
_________________
Patched and tested BIOSes are at http://wims.rainbow-software.org
UniFlash - Flash anything anywhere http://www.uniflash.org

Rainbow · Posted: Sun Apr 18, 2004 7:31 pm Post subject:

GOT IT
Finally, after that long time... Very Happy

Hacked out of awdflash v7.52 that was bundled with one of DTK BIOSes for this board.

NickS · Posted: Mon Apr 19, 2004 12:16 pm Post subject:

Sorry, Rainbow - I don't understand the syntax you are using here. What is meant by (e.g.)
[05555],080 ?
Using debug, can I create a pair of little .com files to unlock and lock ?
_________________
Tested patched BIOSes. Untested patched BIOSes .
Emails *will* be ignored unless the subject line starts "Wim's BIOS forum"

Rainbow · Posted: Mon Apr 19, 2004 5:12 pm Post subject:

"[05555],0AA" means that you write data 0AAh to address 5555h in the flash ROM. If you read a datasheet for some flash ROM, it will become clear.
I'm now thinking about how to include this in UniFlash...
_________________
Patched and tested BIOSes are at http://wims.rainbow-software.org
UniFlash - Flash anything anywhere http://www.uniflash.org

NickS · Posted: Tue Apr 20, 2004 6:43 pm Post subject:

Fine, thanks. Smile

_________________
Tested patched BIOSes. Untested patched BIOSes .
Emails *will* be ignored unless the subject line starts "Wim's BIOS forum"

Rainbow · Posted: Tue Apr 20, 2004 8:07 pm Post subject:

Any ideas about how this should be implemented in UniFlash?
I'm thinking about adding new menu that will include bootblock lock/unlock and maybe some (destructive) tests - write all zeros, all ones...
It's a lot of work to do so I'll release v1.35 before.
_________________
Patched and tested BIOSes are at http://wims.rainbow-software.org
UniFlash - Flash anything anywhere http://www.uniflash.org

wsw243 · Posted: Tue Apr 20, 2004 8:47 pm Post subject:

Rainbow · Posted: Tue Apr 20, 2004 9:19 pm Post subject:

For example:
http://www.winbond-usa.com/products/winbond_products/view.phtml?name=MP
_________________
Patched and tested BIOSes are at http://wims.rainbow-software.org
UniFlash - Flash anything anywhere http://www.uniflash.org

edwin · Posted: Wed Apr 21, 2004 8:53 pm Post subject:

xam · Posted: Thu Dec 30, 2004 5:00 pm Post subject:

Thanks Rainbow for the disable lockout mode code!
Today i have add the code in the ct flasher (original flasher ftp://ftp.heise.de/pub/ct/projekte/ctflash.zip ). I put the code before the erase-code for the W29C020C and it works.