It is believed that all R400 laptops are compatible.
There are two possible flash chip sizes for the R400: 4MiB (32Mbit) or 8MiB (64Mbit). This can be identified by the type of flash chip below the palmrest: 4MiB is SOIC-8, 8MiB is SOIC-16.
The R400 laptops come with the ME (and sometimes AMT in addition) before flashing libreboot. Libreboot disables and removes it by using a modified descriptor: see gm45_remove_me.html (contains notes, plus instructions)
Flashing instructions can be found at ../install/index.html#flashrom
Usual limitations apply for native graphics initialization (no VBT and/or INT10H and only GRUB works so no BIOS, so no DOS/Windows support - who cares? There is no system but GNU, and Linux is one of it's kernels).
When connecting the AC adapter while system is powered off, system will then power on. This probably happens in coreboot aswell (with or without blobs). It's a minor annoyance, but it should be fixed (if it's not already fixed by now).
This method of disabling the ME leaves the flash descriptor and gbe in place (non-functional data, fully documented) and disables the ME using soft straps. This means that the gigabit ethernet will still work (putting the machine in non-descriptor mode would wipe it out).
The R400, when run without CPU microcode updates in coreboot, currently kernel panics if running QEMU with vt-x enabled on 2 cores for the guest. With a single core enabled for the guest, the guest panics (but the host is fine). Working around this in QEMU might be possible; if not, software virtualization should work fine (it's just slower).
The following errata datasheet from Intel might help with investigation: http://download.intel.com/design/mobile/specupdt/320121.pdf
Copyright © 2014, 2015 Francis Rowe <info@gluglug.org.uk>
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