t500.md 5.4 KB
% ThinkPad T500
It is believed that all or most T500 laptops are compatible. See notes about CPU compatibility for potential incompatibilities.
There are two possible flash chip sizes for the T500: 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 T500 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/#flashrom
EC update {#ecupdate}
It is recommended that you update to the latest EC firmware version. The EC firmware is separate from libreboot, so we don't actually provide that, but if you still have Lenovo BIOS then you can just run the Lenovo BIOS update utility, which will update both the BIOS and EC version. See:
- https://libreboot.org/docs/install/index.html#flashrom
- http://www.thinkwiki.org/wiki/BIOS_update_without_optical_disk
NOTE: this can only be done when you are using Lenovo BIOS. How to update the EC firmware while running libreboot is unknown. Libreboot only replaces the BIOS firmware, not EC.
Updated EC firmware has several advantages e.g. bettery battery handling.
Compatibility (without blobs) {#compatibility_noblobs}
Hardware virtualization (vt-x) {#hwvirt}
The T500, 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).
On GM45 hardware (with libreboot), make sure that the kvm and kvm_intel kernel modules are not loaded, when using QEMU.
The following errata datasheet from Intel might help with investigation: http://download.intel.com/design/mobile/specupdt/320121.pdf
The T500 is almost identical to the X200, code-wise. See x200.html.
Descriptor and Gbe differences {#descriptor_difference}
See ../future/dumps/t500_x200_descriptor/descriptor_diff_t500_x200.txt and ../future/dumps/t500_x200_descriptor/gbe_diff_t500_x200.txt
The patches above are based on the output from ich9deblob on a factory.rom image dumped from the T500 with a SOIC-8 4MiB flash chip. The patch re-creates the X200 descriptor/gbe source, so the commands were something like:
$ diff -u t500gbe x200gbe
$ diff -u t500descriptor x200descriptor
ME VSCC table is in a different place and a different size on the T500. Libreboot disables and removes the ME anyway, so it doesn't matter.
The very same descriptor/gbe used on the X200 (generated by ich9gen) was re-used on the T500, and it still worked.
Hardware register dumps {#regdumps}
The coreboot wiki shows how to collect various logs useful in porting to new boards. Following are outputs from the T500:
- T500 with Macronix MX25L3205D flash chip (4MiB, SOIC-8) and Lenovo BIOS 3.13 7VET83WW (EC firmware 1.06):
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