latitude.md 6.0 KB
title: Flashing Canoeboot on Dell Latitude laptops x-toc-enable: true ...
All of the Dell Latitude models can be flashed internally, which means that you do not need to disassemble them. You can do it from GNU+Linux or BSD, using the instructions on this page.
Disable security before flashing
Please also disable /dev/mem protection, otherwise flashprog and dell-flash-unlock won't work. You can re-enable the protections after flashing.
Please also disable SecureBoot, if you're using a UEFI-based mainboard. Note that Canoeboot does not currently implement UEFI on x86 platforms, but you can set up Secure canoeBoot after flashing.
MAC address
Make sure to set your own MAC address in the ROM image before flashing. Please read the nvmutil manual which says how to do this.
Thermal safety
Thermal safety: this machine shuts down very quickly, when the machine exceeds 80c CPU temperature, which is far more conservative than on most laptops (non-Dell ones), so you should make sure that your thermals are excellent. More info available here. This is a known bug, but otherwise the machine will be mostly stable.
Machine-specific notes
Latitude E6400
Vendor files not required for Dell Latitude E6400 if you have the Intel GPU.
If you have the Nvidia model, please use the e6400nvidia_4mb target, and
make sure to run the inject script.
dGPU variants
Only the models with Intel graphics are supported in Canoeboot, since these can be booted with free graphics initialisation, whereas the discrete GPUs require binary blobs which are not allowed in Canoeboot.
Internal flashing
You can simply boot GNU+Linux or BSD, on the Dell Latitude you wish to flash,
and run flashprog from there, for Canoeboot installation. Certain other steps
are also required, documented in the steps below:
You can flash Canoeboot directly from the vendor (Dell) BIOS, without taking the machine apart. It can be done entirely from GNU+Linux or BSD.
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 cbmk.git repository, or in releases.
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
Please make sure that you do fully read the README, because it contains useful information.
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; on some
systems, you have to boot the machine back up manually, after power down. 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.
MAKE SURE to back up the original firmware image first:
flashprog -p internal -r factory.rom
When you flash it, you can use this command:
flashprog -p internal -w canoeboot.rom
Where canoeboot.rom is your Dell Latitude ROM. Make sure it's the right
one. If flashprog 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 flashprog: -c MX25L3205D/MX25L3208D.
So:
flashprog -p internal -w canoeboot.rom -c MX25L3205D/MX25L3208D
When you see flashprog say VERIFIED at the end, that means the flash was
successful. If you don't see that, or you're unsure, please contact the
Canoeboot project via IRC.
External flashing
General guidance
Machine-specific disassembly instructions not provided, but you can find the hardware maintenance manual for your Latitude module online. Just search for it. The flash chips(s) is/are usually under the keyboard/palmrest. Near to the PCH/southbridge.
Note that you often have to provide a high current for VCC, because the flash chip will share a common voltage rail with other power-hungry ICs on the board, or the flash ICs will share a common MISO/MOSI line without resistance, with chip selects controlled by PCH, and/or the PCH itself might be live while flashing - so you need to set the drive strength high.
Take stock of the above advice, which is also mentioned on the external SPI flashing guide.
Please read the external SPI flash guide
External flashing is usually not required, on these machines.
Chip size guidance
SOme Dell Latitudes use a single flash chip, so you can just use the ROM images as-is.
If there are two flash chips, you must split the ROM images. Check the silk screen on the board, and the first chip might be labelled something like SPI1, second one SPI2. Figure out which one is first.
Look at the part number on the chip and find the flash size for it. For example: a 10MB flash might be 2MB for SPI1 and 8MB for SPI2, so you would do:
dd if=canoeboot.rom of=spi1.rom bs=1M count=2
dd if=canoeboot.rom of=spi2.rom bs=1M skip=2
Adapt accordingly, to the exact flash configuration on your machine. 16MB is likely one chip. 12MB is usually SPI1 8MB and SPI2 4MB so you would do:
dd if=canoeboot.rom of=spi1.rom bs=1M count=8
dd if=canoeboot.rom of=spi2.rom bs=1M skip=8
If in doubt, just ask on Canoeboot IRC.