Re: lenovo c540

[Mike Banon]

You need to extract a clean BIOS ROM ( "clean" = without any
system-specific settings ) from a BIOS update utility. Try to open
this utility (called something like "winflash_3.00.exe") as an archive
with 7zip, and extract the contents of this .exe file using 7zip. If
successful, it would give you a set of files, one of which might
contain this clean BIOS ROM. Could be called something like
WinVALGC300.bin ( you could guess it by looking at the file sizes ).
Then open this file using a hexedit, search for $_IFLASH_BIOSIMG
header. Not directly after but slightly further after this header, at
the closest address ending by 0 (rounded by 0x10) there is a start of
BIOS section, the size of which should be equal to a size of your BIOS
chip. Copy-paste it into a new binary file, then you could try using
it (but only after making a backup of your current chip contents!).
You could also compare the contents of your original ROM image vs this
"clean" image, to get an idea where a password might be stored (could
be encoded instead of a plain text).

On Thu, Aug 15, 2019 at 4:27 PM Darko Svilkovic
 wrote:
> Hi,
>
> Yes flashed with a windows update tool,which automaticly updates,has no download ...
>
> Any help which program tu use to download the bios ...
>
> Read somthing like there are 2 chips for bios (one for bios and the other for password and settings) ...
>
> thx
>
> On Thu, Aug 15, 2019 at 2:28 PM Mike Banon  wrote:
> > "I have flashed the bios to a new version" - how you did that, using a
> > windows tool provided by a laptop manufacturer? If yes, then it
> > preserves the originally set password and maybe the other settings.
> > Try to extract a "clean" BIOS image from the BIOS update utility
> > provided by a laptop manufacturer. Then, using a flashrom-supported
> > programmer like USB CH341A with a test clip (SOIC8 ?) together with
> > our flashrom opensource tool, you might be able to flash a clean BIOS
> > image (without any passwords/settings) into your BIOS chip. Of course
> > please make a backup before flashing a new image, in the case it's
> > incorrect or you'd need to borrow some Intel ME-related regions or to
> > have a MAC address specified in your ROM in order for onboard Ethernet
> > working.
> >
> > On Wed, Aug 7, 2019 at 12:01 PM Darko Svilkovic
> >  wrote:
> > > hi,
> > >
> > > Hawe a problem with lenovo c540 AIO,bought this from a second hand,and didn't see,and he didn,t mention that there is a bios admin pass ...
> > >
> > > I have flashed the bios to a new wersion,taked out the cmos battery,jumpered the cmos jumper but with no success ...
> > >
> > > Now i heard that the password is in eeprom ...
> > >
> > > How to remowe it ???
> > >
> > > thx
> > >
> > > Darko/Croatia
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