[flashrom] modifying the BIOS of an Acer C720 from within FreeBSD CURRENT

[Stefan Tauner]

On Tue, 12 Sep 2017 13:44:31 +0200
Matthias Apitz <guru at unixarea.de> wrote:

> Hello,
> 
> This is with flashrom of FreeBSD CURRENT amd64.
> 
> The background: To be able to install and boot FreeBSD on an Acer C720
> Chromebook, one must tweak some bits in the BIOS and enable a so called
> LEGACY BIOS mode (after removing the hardware write protection of the
> BIOS). To do so, there are some tools within ChromeOS which allow this
> procedure, but after this you can not boot ChromeOS anymore (from the
> saved SSD) and so you can't use these tools within ChromeOS to switch
> the bits back.
> 
> The tools to use are simple:
> 
> # flashrom -p internal -i GBB -r bios.bin
> # futility gbb -s --flags=$flags bios.bin
> # flashrom -p host -i GBB --fast-verify -w bios.bin

According to these commands you want to use the chromiumos fork of
flashrom for this not the one provided by distributions or flashrom.org.

> Flashrom we have in the FreeBSD ports as sysutils/flashrom and it seems
> to works:
> 
> $ flashrom -R
> flashrom v0.9.9-r1955 on FreeBSD 12.0-CURRENT (amd64)
> flashrom is free software, get the source code at https://flashrom.org
> 
> $ flashrom -L | egrep -i 'acer|720|chro'
> Acer            V75-M                                   OK
> Acer            EM61SM/EM61PM                           OK
> GIGABYTE        GA-M720-US3                             OK
> MSI             MS-7207 (K8NGM2-L)                      OK      (autodetected)
> Acer       Aspire 1520         OK
> Acer       Aspire One          BAD
> 
> $ flashrom -p internal -i GBB -r bios.bin
> flashrom v0.9.9-r1955 on FreeBSD 12.0-CURRENT (amd64)
> flashrom is free software, get the source code at https://flashrom.org
> 
> Region requested (with -i "GBB"), but no layout data is available.
> 
> What does this error message mean?

The vanilla flashrom expects a layout file to specify the address range.

-- 
Kind regards/Mit freundlichen Grüßen, Stefan Tauner