11 KiB
| title | x-toc-enable |
|---|---|
| Flashing the Dell Latitude E6400 | true |
The microcode bugfixes/mitigations added for GM45 are also applicable to this board, for users who are interested. Read that article for more information.
Libreboot still recommends that boot with CPU microcode updates, by default, for all the reasons described by Libreboot's Binary Blobs Reductions Policy but this board run reasonably well without them.
A note about GPUs
We confirm that the Nvidia models are PM45, and therefore will require a VGA
ROM for initialisation. This is supported in Libreboot after the 20230625
release, if you compile from source; the e6400_4mb target can work on both
variants, but will need the Nvidia VGA ROM inserted to work on Nvidia models.
This insertion is handled automatically in newer lbmk revisions, during build
time, or you can insert it on a release rom
after 20230625. - A Video BIOS Option
ROM is used, in this configuration. Libreboot's
build system automatically downloads this at build time, or it can handle that
for you in the same way if it was scrubbed from a release ROM.
Models with Intel graphics are GM45, and fully supported in Libreboot with native initialisation; ROM images are available since Libreboot 20230423. The Intel video initialisation is libre, implemented with publicly available source code via libgfxinit, from the coreboot project.
Flash chip size
Use this to find out:
flashrom -p internal
We believe most/all are 4MB (32Mb) flash sizes, but larger ROM images are provided for people who wish to upgrade.
MAC address
The MAC address is part of the ROM image that you're flashing. You can change it at any time, before or after you've flashed Libreboot; you can also change it in the Dell BIOS, if you really want to. This is for the onboard gigabit ethernet device.
Refer to mac_address.md.
It is recommended that you run nvmutil. See:
The nvmutil software is specifically designed for changing MAC addresses,
and it implements a few more safeguards (e.g. prevents multicast/all-zero
MAC addresses) and features (MAC address randomisation, ability to correct or
intententionally corrupt(disable) GbE sections if you wish, swap GbE parts,
etc). You can also run ich9gen, if you wish:
Intel GPU: libre video initialisation available
Libreboot uses coreboot's native libgfxinit on this platform, for
variants with Intel graphics.
For Intel GPU variants, Libreboot 20230423 and up have full support. Simply flash a release ROM, if you wish.
Nvidia GPU: Video BIOS Option ROM required
NOTE: nouveau (Linux video driver) is unstable when it was last tested, in
this setup. Either specify nomodeset kernel option, or use another
operating system such as OpenBSD. More information is written on the
E6400 hardware page, regarding OS compatibility.
This is unavailable in Libreboot 20230423 and 20230625, but a future release
will contain support for these variants; for now, you must compile Libreboot
from Git. It is available in the default master branch of lbmk, under
build target e6400_4mb - either build from source and it gets inserted
automatically, or you can insert it
manually on future release ROMs past Libreboot 20230625.
An earlier experimental revision existed in the e6400nvidia_wip branch of
lbmk, as build target e6400nvidia_4mb, but it was decided that since SeaBIOS
is the only payload anyway on this board, having just a single build target is
more efficient if that can (and it does) support both variants.
Actual installation is the same as with regular E6400 (Intel GPU) variants. Refer to the E6400 flashing instructions.
The e6400nvidia_wip is used, because this version is still under development.
Problems with Linux video drivers on Nvidia
Technically, there is nothing wrong with Libreboot itself, but the nouveau
driver hangs/crashes on Nvidia models, after booting Linux with the Nvidia VGA
ROM loaded from coreboot.
Until that is fixed, you must specify nomodeset in your Linux kernel boot
parameters.
Refer to development discussion for more information - testers needed!
The Intel GPU variant of E6400 is more stable, and works fully, with full
acceleration - the Nvidia models can only be run in software, and the BSD
systems only have the slow nv driver (which is nonetheless stable).
Nvidia errata
BEFORE you flash it, please know that support for Nvidia variants is a proof of concept. Known issues exist. For more information, please read the E6400 info page, E6400 nvidia news page and the development discussion via codeberg.
How to flash internally (no diassembly)
Warning for BSD users
NOTE (15 October 2023): The util is now called dell-flash-unlock, but it
was previously called e6400-flash-unlock. Links have been updated.
BSD boots and works properly on these machines, but take note:
Nicholas's dell-flash-unlock
utility has not yet been ported to BSD systems. The flashrom software is
available on BSD systems. Libreboot's build system has not yet been ported to
the BSDs.
BSD users could run Linux from USB to run flashrom and dell-flash-unlock.
Virtualisation is available in BSDs, where it should be feasible to run the
Libreboot build system, in Linux, under virtualisation.
NOTE: BSD is mentioned above, but the only BSD tested for dell-flash-unlock
is OpenBSD, as of 15 October 2023.
Flashing from Linux
MAKE SURE you boot with this Linux kernel parameter: iomem=relaxed - this
disables memory protections, permitting /dev/mem access needed by flashrom.
The flash is memory mapped and flashrom accesses it via /dev/mem.
You can flash Libreboot directly from the vendor (Dell) BIOS, without taking the machine apart. It can be done entirely from Linux. It will probably also work on BSD systems, but it has only been testing on Linux thus far.
NOTE (15 October 2023): The util is now called dell-flash-unlock, but it
was previously called e6400-flash-unlock. Links have been updated.
Check util/dell-flash-unlock in the lbmk.git repository, or in release
archives for Libreboot releases from 20230423 onwards.
Go in there:
cd util/dell-flash-unlock
make
With this program, you can unlock the flash in such a way where everything
is writeable. Information about how to use it is in the README.md file which
is included in that program's directory, or you can read it online here:
https://browse.libreboot.org/lbmk.git/plain/util/dell-flash-unlock/README.md
Literally just run that program, and do what it says. You run it once, and shut
down, and when you do, the system brings itself back up automatically. Then
you run it and flash it unlocked. Then you run it again. The source code is
intuitive enough that you can easily get the gist of it; it's writing some EC
commands and changing some chipset config bits. The EC on this machine is
hooked up to the GPIO33 signal, sometimes called HDA_DOCK_EN, which sets
the flash descriptor override thus disabling any flash protection by the IFD.
It also bypasses the SMM BIOS lock protection by disabling SMIs, and Dell's
BIOS doesn't set any other type of protection either such as writing to
Protected Range registers.
When you flash it, you can use this command:
flashrom -p internal -w libreboot.rom
Where libreboot.rom is your E6400 ROM. Make sure it's the right one.
If flashrom complains about multiple flash chips detected, just pick one of
them (doesn't matter which one). On most Dell machines, the most correct
would probably be this option in flashrom: -c MX25L3205D/MX25L3208D.
So:
flashrom -p internal -w libreboot.rom -c MX25L3205D/MX25L3208D
When you see flashrom say VERIFIED at the end, that means the flash was
successful. If you don't see that, or you're unsure, please contact the
Libreboot project via IRC.
BACK UP THE FACTORY BIOS
The -w option flashes libreboot.rom. You may consider backing up the
original Dell BIOS first, using the -r option:
flashrom -p internal -r backup.rom -c MX25L3205D/MX25L3208D
Do this while in a flashable state, after the 2nd run of dell-flash-unlock.
Make sure the backup.rom file gets backed up to an external storage media,
not the E6400 itself.
With this method, you can probably flash it within 5 minutes. Again, zero disassembly required!
How to flash externally
Refer to spi.md as a guide for external re-flashing.
The SPI flash chip shares a voltage rail with the ICH9 southbridge, which is not isolated using a diode. As a result, powering the flash chip externally causes the ICH9 to partially power up and attempt to drive the SPI clock pin low, which can interfere with programmers such as the Raspberry Pi. See RPi Drive Strength for a workaround.
Have a look online for videos showing how to disassemble, if you wish to externally re-flash.