How to obtain a BIOS image from another computer use flashrom？

[zy]

Hi，
   I'm a student from China and I've been learning flashrom，So I would like to know whether the flashrom can support extracting BIOS firmware images under Windows 7/10.
   If I don't have the Internet（Just LAN），how do I remotely obtain a BIOS image from another computer use flashrom？
   Maybe my English not very well. Thank you very much.

   Looking forward to your reply.

 

[Mike Banon]

Good day! The flashrom software has the "internal" mode - using which,
you may be able to access the BIOS chip directly from your OS, if your
hardware is supported. In example:

sudo flashrom -p
internal:laptop=force_I_want_a_brick,amd_imc_force=yes -r
./build/coreflop.rom

I think this mode is available only on Linux (may have to boot with
"iomem=relaxed" kernel flag) - however, you may boot a Linux LiveUSB
on your target PC to use Linux without the installation in a live
mode.

As for "how do I remotely obtain a BIOS image from another computer
using flashrom" - if this internal mode is available to you, and a
target PC is running Linux, you can remotely connect to this PC using
a SSH (or VPN + SSH), run the flashrom command to read a BIOS image
from a chip, and then - using scp - copy the obtained BIOS image to
your own PC

On Fri, Jan 21, 2022 at 3:26 AM zy  wrote:
> Hi，
>    I'm a student from China and I've been learning flashrom，So I would like to know whether the flashrom can support extracting BIOS firmware images under Windows 7/10.
>    If I don't have the Internet（Just LAN），how do I remotely obtain a BIOS image from another computer use flashrom？
>    Maybe my English not very well. Thank you very much.
>
> Looking forward to your reply.
>
> flashrom mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]

[Angel Pons]

Hi,

On Sun, Jan 23, 2022 at 9:49 AM Mike Banon  wrote:
> Good day! The flashrom software has the "internal" mode - using which,
> you may be able to access the BIOS chip directly from your OS, if your
> hardware is supported. In example:
>
> sudo flashrom -p
> internal:laptop=force_I_want_a_brick,amd_imc_force=yes -r
> ./build/coreflop.rom

Mike, can you please explain why you've suggested using such a
dangerous command without even knowing which system it's going to be
run on? The `force_I_want_a_brick` name is intentional, as flashrom
can cause problems on certain laptops (most laptops from the last
decade should be fine, though), c.f. https://www.flashrom.org/Laptops
for a detailed explanation. And you've suggested using `amd_imc_force`
even though it only applies to AMD southbridges using SPI.

I know you're just trying to help, but I'm afraid that suggesting
people to run dangerous commands on unknown hardware without
mentioning the risks is not helpful.
> I think this mode is available only on Linux (may have to boot with
> "iomem=relaxed" kernel flag) - however, you may boot a Linux LiveUSB
> on your target PC to use Linux without the installation in a live
> mode.

On x86, the internal programmer should also work on most BSDs and
Darwin (macOS). It might even work on Solaris.

On Linux, the `iomem=relaxed` kernel parameter can be used when a
kernel module conflicts with the resources flashrom wants to use, but
it reduces the system's security. On Intel systems, unloading the
`lpc_ich` kernel module should allow using flashrom's internal
programmer without having to boot with `iomem=relaxed`.
> As for "how do I remotely obtain a BIOS image from another computer
> using flashrom" - if this internal mode is available to you, and a
> target PC is running Linux, you can remotely connect to this PC using
> a SSH (or VPN + SSH), run the flashrom command to read a BIOS image
> from a chip, and then - using scp - copy the obtained BIOS image to
> your own PC
>
> On Fri, Jan 21, 2022 at 3:26 AM zy  wrote:
> > Hi，
> >    I'm a student from China and I've been learning flashrom，So I would like to know whether the flashrom can support extracting BIOS firmware images under Windows 7/10.
> >    If I don't have the Internet（Just LAN），how do I remotely obtain a BIOS image from another computer use flashrom？
> >    Maybe my English not very well. Thank you very much.

On Windows, flashrom's internal programmer is unusable. It requires
libpci and raw memory access; libpci is not available on Windows as
far as I know, and I think Windows restricts raw memory access from
userspace code for security reasons. One could try to implement the
required functionality in a driver, but one would also need to
convince Microsoft to sign the driver. It could be done, but it's not
easy. No one is working on this, as far as I know.
> > Looking forward to your reply.
> >
> > flashrom mailing list -- [e-mail]
> > To unsubscribe send an email to [e-mail]

Best regards,
Angel

[Mike Banon]

Hi there Angel, thank you for your reply and clarification! Please
tell, is this command
> sudo flashrom -p internal:laptop=force_I_want_a_brick,amd_imc_force=yes -r ./build/coreflop.rom

- dangerous to run, even if it's only trying to read (-r) and not
write? (aside from "irritating the EC" possibly causing a sudden
power-off). As for "amd_imc_force=yes", sorry was my mistake

On Mon, Jan 24, 2022 at 3:28 PM Angel Pons  wrote:
> Hi,
>
> On Sun, Jan 23, 2022 at 9:49 AM Mike Banon  wrote:
> > Good day! The flashrom software has the "internal" mode - using which,
> > you may be able to access the BIOS chip directly from your OS, if your
> > hardware is supported. In example:
> >
> > sudo flashrom -p
> > internal:laptop=force_I_want_a_brick,amd_imc_force=yes -r
> > ./build/coreflop.rom
>
> Mike, can you please explain why you've suggested using such a
> dangerous command without even knowing which system it's going to be
> run on? The `force_I_want_a_brick` name is intentional, as flashrom
> can cause problems on certain laptops (most laptops from the last
> decade should be fine, though), c.f. https://www.flashrom.org/Laptops
> for a detailed explanation. And you've suggested using `amd_imc_force`
> even though it only applies to AMD southbridges using SPI.
>
> I know you're just trying to help, but I'm afraid that suggesting
> people to run dangerous commands on unknown hardware without
> mentioning the risks is not helpful.
> > I think this mode is available only on Linux (may have to boot with
> > "iomem=relaxed" kernel flag) - however, you may boot a Linux LiveUSB
> > on your target PC to use Linux without the installation in a live
> > mode.
>
> On x86, the internal programmer should also work on most BSDs and
> Darwin (macOS). It might even work on Solaris.
>
> On Linux, the `iomem=relaxed` kernel parameter can be used when a
> kernel module conflicts with the resources flashrom wants to use, but
> it reduces the system's security. On Intel systems, unloading the
> `lpc_ich` kernel module should allow using flashrom's internal
> programmer without having to boot with `iomem=relaxed`.
> > As for "how do I remotely obtain a BIOS image from another computer
> > using flashrom" - if this internal mode is available to you, and a
> > target PC is running Linux, you can remotely connect to this PC using
> > a SSH (or VPN + SSH), run the flashrom command to read a BIOS image
> > from a chip, and then - using scp - copy the obtained BIOS image to
> > your own PC
> >
> > On Fri, Jan 21, 2022 at 3:26 AM zy  wrote:
> > > Hi，
> > >    I'm a student from China and I've been learning flashrom，So I would like to know whether the flashrom can support extracting BIOS firmware images under Windows 7/10.
> > >    If I don't have the Internet（Just LAN），how do I remotely obtain a BIOS image from another computer use flashrom？
> > >    Maybe my English not very well. Thank you very much.
>
> On Windows, flashrom's internal programmer is unusable. It requires
> libpci and raw memory access; libpci is not available on Windows as
> far as I know, and I think Windows restricts raw memory access from
> userspace code for security reasons. One could try to implement the
> required functionality in a driver, but one would also need to
> convince Microsoft to sign the driver. It could be done, but it's not
> easy. No one is working on this, as far as I know.
> > > Looking forward to your reply.
> > >
> > > flashrom mailing list -- [e-mail]
> > > To unsubscribe send an email to [e-mail]
>
> Best regards,
> Angel

[Nico Huber]

Hi Mike,

On 29.01.22 15:50, Mike Banon wrote:
> Hi there Angel, thank you for your reply and clarification! Please
> tell, is this command
> > sudo flashrom -p internal:laptop=force_I_want_a_brick,amd_imc_force=yes -r ./build/coreflop.rom
> dangerous to run, even if it's only trying to read (-r) and not
>
> write? (aside from "irritating the EC" possibly causing a sudden
> power-off).

if one doesn't know the mainboard, it is indeed dangerous even for
probing. Otherwise it wouldn't be a scary option ;)

If one knows the mainboard and that the flash chip is *not* connected
via LPC/FWH _through_ the EC, then one can remove the need of this
option by adding an entry to `board_enable.c`.

Nico