2024-02-11 23:09:41 +00:00
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tree="default"
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xarch="i386-elf"
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coreboot: only run GRUB as a secondary payload
See:
https://codeberg.org/libreboot/lbmk/issues/216
Almost all users will be OK running GRUB, but a
minority of users have experienced a fatal error
pertaining to grub_free() or grub_realloc() (as
my investigation of GRUB sources reveal when grepping
the error reported in the link above).
We don't yet know what the bug is, only that the
error occurs, leading to an effective brick if the
user has GRUB as their primary payload.
So far, it has only been reported on some Intel
SandyBridge-based Dell Latitudes in Libreboot, but
we can't be too sure.
The user reported that memtest86+ passes just fine,
and SeaBIOS works; BIOS GRUB also works, which means
that the bug is likely only in an area of GRUB that
runs specifically on the coreboot payload, so it's
probably a driver in GRUB when running on the metal
rather than BIOS/UEFI.
The build system supports a configuration whereby
SeaBIOS is the primary payload, but GRUB is available
in the SeaBIOS boot select menu, and an additional
configuration is available where GRUB is what SeaBIOS
executes first (while still providing boot select);
both of these are now the *only* configurations
available, on all x86 targets except QEMU.
The QEMU target is fine because if the bug occurs there,
you can just close QEMU and try a different image.
Even after this bug is later identified and fixed,
the GRUB source code is vastly over-engineered and there
are likely many more such bugs. SeaBIOS is a reliable
payload; the code is small and robust. Remember always:
Code
equals
bugs
Therefore, this configuration change is likely going
to be permanent. This will apply in the next release.
Signed-off-by: Leah Rowe <leah@libreboot.org>
2024-05-27 13:24:26 +00:00
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payload_seabios="y"
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roms: only support SeaBIOS/SeaGRUB on x86
Never, ever build images where GRUB is the primary payload.
These options have been removed from target.cfg handling:
* seabios_withgrub
* grub_withseabios
The "payload_grub" variable now does the same thing as
the old "seabios_withgrub" variable, if set.
The "grubonly" configuration is retained, and enabled by
default when SeaGRUB is enabled (non-grubonly also available).
Due to lbmk issue #216, it is no longer Libreboot policy to
make GRUB the primary payload on any board. GRUB's sheer size
and complexity, plus the large number of memory corruption issues
similar to it that *have* been fixed over the years, tells me
that GRUB is a liability when it is the primary payload.
SeaBIOS is a much safer payload to run as primary, on x86, due
to its smaller size and much more conservative development; it
is simply far less likely to break.
If GRUB breaks in the future, the user's machine is not
bricked. This is because SeaBIOS is the default payload.
Since I no longer wish to ever provide GRUB as a primary
payload, supporting it in lbmk adds needless bloat that
will later probably break anyway due to lack of testing,
so let's just assume SeaGRUB in all cases where the user
wants to use a GRUB payload.
You can mitigate potential security issues with SeaBIOS
by disabling option ROM execution, which can be done at
runtime by inserting integers into CBFS. The SeaBIOS
documentation says how to do this.
Libreboot's GRUB hardening guide still says how to add
a bootorder file in CBFS, making SeaBIOS only load GRUB
from CBFS, and nothing else. This, combined with the
disablement of option ROM execution (if using Intel
graphics), pretty much provides the same security benefits
as GRUB-as-primary, for example when setting a GRUB password
and GPG checks, with encrypted /boot as in the hardening guide.
Signed-off-by: Leah Rowe <leah@libreboot.org>
2024-06-22 21:57:39 +00:00
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payload_grub="y"
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2024-02-11 23:09:41 +00:00
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payload_memtest="y"
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2024-05-27 20:33:53 +00:00
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grub_scan_disk="ahci"
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lib.sh: more unified config handling
replace it with logic that simply uses "." to load
files directly. for this, "vcfg" is added as a variable
in coreboot target.cfg files, referring to a directory
in config/vendor/ containing a file named pkg.cfg, and
this file then contains the same variables as the
erstwhile config/vendor/sources
config/git files are now directories, also containing
pkg.cfg files each with the same variables as before,
such as repository link and commit hash
this change results in a noticeable reduction in code
complexity within the build system.
unified reading of config files: new function setcfg()
added to lib.sh
setcfg checks if a config exists. if a 2nd argument is
passed, it is used as a return value for eval, otherwise
a string calling err is passed. setcfg output is passed
through eval, to set strings based on config; eval must
be used, so that the variables are set within the same
scope, otherwise they'd be set within setcfg which could
lead to some whacky results.
there's still a bit more more to do, but this single change
results in a substantial reduction in code complexity.
Signed-off-by: Leah Rowe <leah@libreboot.org>
2024-06-22 01:35:25 +00:00
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vcfg="hp8560w"
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