On machines without a TPM, we'd still like some way for the BIOS to
attest that it has not been modified. With a Librem Key, we can have the
BIOS use its own ROM measurement converted to a SHA256sum and truncated
so it fits within an HOTP secret. Like with a TPM, a malicious BIOS with
access to the correct measurements can send pre-known good measurements
to the Librem Key.
This approach provides one big drawback in that we have to truncate the
SHA256sum to 20 characters so that it fits within the limitations of
HOTP secrets. This means the possibility of collisions is much higher
but again, an attacker could also capture and spoof an existing ROM's
measurements if they have prior access to it, either with this approach
or with a TPM.
Signed-off-by: Kyle Rankin <kyle.rankin@puri.sm>
Busybox no longer has CONFIG_BASH since we are deploying bash on most
boards. We also should clearly indicate which scripts cannot use
bashisms.
Change shebang in x230-flash.init, t430-flash.init, flash.sh to
/bin/ash. Execute /bin/sh for interactive shells.
Move key functions needed by those scripts to initrd/etc/ash_functions.
Source ash_functions instead of functions in those scripts, so any
bashisms in other functions won't break parsing of the script in ash.
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
- Add TRACE function tracing output under etc/functions, depending on CONFIG_ENABLE_FUNCTION_TRACING_OUTPUT enabled in board configs
- Replace current DEBUG to TRACE calls in code, reserving DEBUG calls for more verbose debugging later on (output of variables etc)
- add 'export CONFIG_ENABLE_FUNCTION_TRACING_OUTPUT=y' in qemu-coreboot(fb)whiptail-tpm1(-hotp) boards to see it in action
- Have Talos II supported by detecting correctly size of mtd chip (not internal: different flashrom output needs to be parsed for chip size)
- Read SPI content only once: 66% speedup (TOCTOU? Don't think so, nothing should happen in parallel when flashing insingle user mode)
- Have the main flash_progress loop not break, but break in flash_rom state subcases (otherwise, verifying step was breaking)
- Change "Initializing internal Flash Programmer" -> "Initializing Flash Programmer"
- Apply changes suggested by @SergiiDmytruk under https://github.com/osresearch/heads/pull/1230#issuecomment-1295332539 to reduce userland wasted time processing flashrom -V output
Show state of flashrom reads/writes by means of a progress bar,
as used in the Librem coreboot flashing scripts
v2: add adjustment for use with `--ifd`
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
* modules/coreboot: add option to use coreboot 4.11
Port patches from coreboot 4.8.1 to 4.11:
* 0000-measure-boot -> 0001
* 0010-cross-compiler-support
All other patches for coreboot 4.8.1 have either already been
integrated, or are for platforms which do not need to be migrated
to coreboot 4.11 (they will move to 4.12 or newer).
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
* patches/coreboot-4.11: Add Broadwell-DE platform patch
Add a patch for FSP Broadwell-DE to make use of Heads' measured boot.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
* patches/coreboot-4.11: Add patch to read serial # from CBFS
Will be used by multiple Librem boards.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
* patches/coreboot-4.11: add board support for Librem Server L1UM
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
* Librem Server L1UM: add new board
Add board config, coreboot config, kernel config files.
Add conditional purism-blobs dependency to coreboot-4.11 module.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
* flash.sh: add special handling for librem_l1um board
Add support for persisting PCIe config via PCHSTRP9 in flash descriptor.
This is needed to support multiple variants of the L1UM server which
use the same firmware but differ in PCIe lane configuration via the
PCH straps configuration in the flash descriptor.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
* patches/coreboot-4.11: Add 'Use PRIxPTR to print uintptr_t' patch
Cherry-picked from upstream coreboot (post-4.11), fixes compilation issue.
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
* CircleCI: add target to build board librem_l1um
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
As part of the config gui we want to be able to have the system define
new config options without them being lost if the user makes their own
changes in CBFS. To allow that this change creates a function initiated
in init that combines all /etc/config* files into /tmp/config. All
existing scripts have been changed to source /tmp/config instead of
/etc/config. The config-gui.sh script now uses /etc/config.user to hold
user configuration options but the combine_configs function will allow
that to expand as others want to split configuration out further.
As it stands here are the current config files:
/etc/config -- Compiled-in configuration options
/etc/config.user -- User preferences that override /etc/config
/tmp/config -- Running config referenced by the BIOS, combination
of existing configs
If we want to modify a running BIOS we will need the ability to pull
down the current BIOS, modify it, and then reflash. This change adds a
read option to flash.sh and pulls down three versions of the BIOS and
only exists successfully if all three match.
To keep the flash logic simpler the GUI logic has been split into a
flash-gui.sh program so flash.sh behaves closer to the original flashrom
scripts it was based from. I've also removed the previous flashrom
scripts and incorporated their options into flash.sh. Finally I set
CONFIG_BOARD via the Makefile instead of setting a duplicate option in
each board's config.
Based on the conversation for PR #406, we decided to go with a more
generic script for general-purpose flashing instead of having individual
(and therefore very similar) flash scripts for each board type. This
script currently handles flashrom on Librem and X230 board types and
introduces a new CONFIG_BOARD option that sets specific flashrom
arguments based on the board.
It also adds support to gui-init to call this flash script.
