Flash chip write enable

Only for programmers and BIOS gurus with technical questions.
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nicolae788
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Thu Feb 19, 2015 11:06 am

Hello,

I am interested how and where should i address the *.rom file of the bios in order to permanently activate the GPIO pin in the chipset that activates the flash ok for the chip. For the moment the TBL pin on the flash chip it's blocked so the Top boot block it's protected. It seems to be like finding a needle in the hay stack, trying to find were in the rom file this protection it's living. Can someone let me know were i have to look for this protection.

The board which i am trying to use for a hot flash it's an Asus P5W-DH and has a Intel ich7R chipset and the chip it's an SST49LF008A. The chip it's recognized, but the TBL pin it's pulled low so it means it's write protected. If i enter ezflash inside the BIOS setup the pin it's pulled high and write it's enabled. But ezflash does not work with hot flash procedure.

I am using flashrom inside Linux CLI enviroment. I already tested the software on other boards but those were write enabled for the flash chip and they do not recognize my flash chip SST49LF008A :(

Thank you !

Alex.
edwin
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Thu Feb 19, 2015 4:05 pm

Are you using the latest version of flashrom? As it seems they are specifically doing a board enable and a chip unlock for each board.
They have an unlock for the SST49LF008A chip on a P5BV-M.
edwin/evasive

Do not assume anything

System error, strike any user to continue...
nicolae788
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Fri Feb 20, 2015 1:51 am

I saw that, but the chipset on that board it's ICH8, so i do not know if they have the same GPIO assignment. Will give it a try anyway on my ICH7R chipset with the mainboard option and see what happens.

Anyway i will appreciate if someone knows a procedure of finding the needle in the hay stack :)

Thank you
edwin
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Fri Feb 20, 2015 10:22 am

From this bit:

Code: Select all

/* ICH7 and ICH8-based */
334 static struct ichx_desc ich7_desc = {
335         .ngpio = 50,
336         .have_blink = true,
337         .regs = ichx_regs,
338         .reglen = ichx_reglen,
http://lxr.free-electrons.com/source/dr ... gpio-ich.c

It looks like ICH7/ICH8 have the same logic for programming them... Let us know how things go and if you are succesful please confirm to the fine people at flashrom.
edwin/evasive

Do not assume anything

System error, strike any user to continue...
nicolae788
Chip off the ol' block
Posts: 102
Joined: Thu Mar 11, 2004 8:24 pm
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Fri Feb 20, 2015 12:45 pm

Hi,

It doesn't work specifying another board that it's listed as supported. I already tried with specifying other boards that have the support on flashrom page and have the ICH7R chipset, but it just says that it's aborting to be safe because no suitable board enable was found for the manufacturer and model specified.

What looks strange to me it's that every time i run flashrom even just for checking the detection of the chipset and flash chip it say that "enabling flash write....OK"; could that be a standard response or it's based on some feedback from the chipset??? However checking the TBL pin on the PLCC it's still pulled low so no write enable for the top boot block which means no Write enabled....

Maybe i have to dissasemble the EZFlash application found in the Bios. When i run that application from whithin the Bios i get +3.3V on the TBL pin which it's the guarantee to write enable. Or i could simply find the address in the bios ROM for this board that addresses the write protect and change it to off, but decoding the info on the ROM and finding that specific address could be a nightmare...

Any suggestions are highly appreciated, still !
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