[flashrom] Re: [e-mail] post from [e-mail] requires approval

[Misha Wiesel]

Good morning.

Thank you for your responses.
> Intel doesn't allow direct access to the flash chip with your chipset.
> Hence, the chip never shows up by its actual name "W25Q256JV_M" but only as "Opaque flash chip" and the `-c` option is futile.

Ok, got you.
> Do you know exactly what the firmware of your mainboard does?

When you say "firmware", do you mean BIOS? Or some [other] board-specific firmware? 
    To answer your question I will likely need to query the mainboard vendor, so I need to know what exactly I should ask them...
> It's possible that some other process also tries to write to the chip (e.g. firmware in SMM).

I do not think something else is trying to access the chip at the same time. During my tests, I am running, say, "a minimal system": it is a reduced Ubuntu 18.04 in command-line mode, without any graphics and most of user services/tools; all network interfaces are down, and so all network services are not active, etc.
> You could try the same command again and see if it gives different results. Sometimes it just works by chance.

I tried the same command(s) many time. The result is always the same: error at the same offset [above 128M], and the same f0 vs. f8.
    As far as I can assume according to the offset of the failure, it looks like the "Opaque flash chip" cannot deal correctly with a flash chip of size of 256M (or, of size over 128M)...
> But I can only advice to continue if you have means to recover from a bad flash.

It is not about a single recovery for the bad flash. I have to have a tool that works stable. The goal is to be able to recover/update flash (bios) at any moment with minimal probability of failure.

By the way, do the flashrom requires some specific settings/parameters/etc. in the kernel (kernel.cfg)?

-----Original Message-----
From: Nico Huber  
Sent: יום ב 18 נובמבר 2019 12:23
To: Misha Wiesel ; David Hendricks ; [e-mail]
Subject: Re: [flashrom] Re: [e-mail] post from [e-mail] requires approval

Hi Misha,
> ---------- Forwarded message ----------
> From: Misha Wiesel <[e-mail]>
> To: "[e-mail]" 
> <[e-mail]>
> Cc:
> Bcc:
> Date: Wed, 13 Nov 2019 16:37:22 +0000
> Subject: Flashrom 1.1 + C627 board + W25Q256* flash chip
>             Good morning.
>             I am trying to write the SPI flash using the Fashrom v1.1 for C627 board (Intel PCH) and flash chip W25Q256 JV M.
>             According to release notes for version 1.1, these HW components are supported already by flashrom. But I encounter problems. As it is being asked by flashrom utility, I report about it. Following some details:
>
>
>   First, I read the existing flash. See the attached log file “read-flash.log”.
>
>   Then, I try to write the flash (from its original image) using the -c option. The write fails. See the attached log “write-flash-exact-chip.log”.

Intel doesn't allow direct access to the flash chip with your chipset.
Hence, the chip never shows up by its actual name "W25Q256JV_M" but only as "Opaque flash chip" and the `-c` option is futile.
>   Next, I try to write the flash (from the same image) followed by verification, but without -c option. See the attached log “write-verify-flash.log”.
>
> a.       If it will help… The verification reports an error at address 0x1000008f (values f8 vs f0). Comparison of original and read from flash chip images shows the same difference at the same offset.

Do you know exactly what the firmware of your mainboard does? It's possible that some other process also tries to write to the chip (e.g.
firmware in SMM). You could try the same command again and see if it gives different results. Sometimes it just works by chance. But I can only advice to continue if you have means to recover from a bad flash.

Hope that helps,
Nico