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linuxboot / heads

A minimal Linux that runs as a coreboot or LinuxBoot ROM payload to provide a secure, flexible boot environment for laptops, workstations and servers.
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t440p/w541 marked UNTESTED (boot in 50s) : CONFIG_CBFS_SIZE of 8mb (changed to CONFIG_CBFS_SIZE=0xBE4FFF by need) #1825

Open tlaurion opened 3 weeks ago

tlaurion commented 3 weeks ago

~Why master was not enforcing CONFIG_CBFS_SIZE=0xBE4FFF as all other 12mb opaque flash chips from ivy bridge? (was 8mb). Merged as emergency fix: untested.~ Unfortunately reason was that anything CBFS bigger then 8mb will make Haswell boot in 50s, thanks to improper MRC blob we depend on.

Solution would be to switch to NRI #1711, which is not merged upstream. Board owners: time to participate testing/reviewing/commenting upstream your need/appreciation of memory initialization being free under #1711.

OLD

1826 was merged moving those boars to untested to prevent users from potential bricking without external programmers.

Testing needed from boards testers (BOARDS_TESTERS.md):

TESTED: Master roms will boot, but after 50s see https://github.com/linuxboot/heads/issues/1825#issuecomment-2448636649

Therefore, t440p/w541 boards now build UNTESTED tagged board roms. Be warned.

tlaurion commented 3 weeks ago

Pinned issue

ResendeGHF commented 3 weeks ago

Why master was not enforcing CONFIG_CBFS_SIZE=0xBE4FFF as all other 12mb opaque flash chips from ivy bridge? (was 8mb).

CONFIG_CBFS_SIZE=0xBE4FFF leads to longer RAM initialization times. Relevant information about this issue can be found in #1282. As icon noted, this is likely due to the following reasons:

I assume with the bigger size, not everything in CBFS can be cached. There’s CAR (Cache as RAM) at 0xff7c0000 to 0xff7effff, which is used to store data before the DRAM is initialized. The BIOS region is mapped directly below 4G (at 0x100000000). Therefore, making the CBFS too large could conflict with CAR. I don't believe this can be changed without also modifying the MRC blob. The best option is to set CBFS_SIZE to 8MiB. One can still make the rest of the BIOS region available using a custom FMAP, though it would not be part of CBFS.

Additionally, I've just tested on the W541 board from UNTESTED_w541-maximized (The path under UNTESTED_w541-hotp-maximized.config is inconsistent due to renaming to UNTESTED). As expected, boot time is over 50 seconds.

tlaurion commented 3 weeks ago

@ResendeGHF Maybe its time to switch to native ram init #1711 ? (With its documented downsides) Point is: past value for CBFS (8mb) is not big enough anymore as can be seen from CircleCI failed builds :(

tlaurion commented 3 weeks ago

@ResendeGHF op updated.

tlaurion commented 3 weeks ago

Also note that participating in upstream issue would make this go forward https://ticket.coreboot.org/issues/457

tlaurion commented 2 weeks ago

Proposed collaboration in s3 resume from suspend patchset at https://review.coreboot.org/c/coreboot/+/81897/comments/d4d3ed3a_d6c46137

If you see replies faster than I do, please ping me here.