[coreboot - Bug #617] Missing safeguard: CBFS_SIZE greater than BIOS region in the IFD
Maximilian Brune <[email protected]>
| Newsgroups | gmane.linux.bios |
|---|---|
| Message-ID | <[email protected]> |
Issue #617 has been updated by Maximilian Brune. Did you set CBFS_SIZE too high? ---------------------------------------- Bug #617: Missing safeguard: CBFS_SIZE greater than BIOS region in the IFD https://ticket.coreboot.org/issues/617#change-2190 * Author: gaspar ilom * Status: New * Priority: Normal * Target version: none * Start date: 2025-11-14 * Affected versions: main * Affected hardware: haswell ---------------------------------------- There are no effective safeguards to enforce that the `CONFIG_CBFS_SIZE` does not exceed the bios region as declared in the IFD. ### Impact - Downstream under Heads with a maximized bios region for the Haswell boards (T440p and W541) we could verify that this bug leads to an overflow when training the memory cache that makes it not work. This happens both with MRC blob and NRI and causes very slow boot times (20s) and S3 suspend/resume does not work. - Effects on other boards have not been observed but are possible. ### Expected behavior Coreboot should not build successfully if the `CBFS_SIZE` exceeds the bios region in the IFD and error out reporting the problem that caused this. ## Analysis Full details are under the PR in Heads and in particular this comment by @tlaurion https://github.com/linuxboot/heads/pull/2025/#issuecomment-3524672338 Ifttool reports a bios region of 0xBDEFFF (BDEFFF). However, the coreboot config contained: ``` CONFIG_CBFS_SIZE=0xBE4FFF ``` ``` ./build/x86/coreboot-25.09/util/ifdtool/ifdtool --platform ifd2 --layout w541_layout blobs/w541/ifd.bin && cat w541_layout File blobs/w541/ifd.bin is 4096 bytes Wrote layout to w541_layout 00000000:00000fff fd 00021000:00bfffff bios 00003000:00020fff me 00001000:00002fff gbe ``` After fixing the `CONFIG_CBFS_SIZE` the issues were fixed and fast boot with trained memory cache and S3 suspen/resume work again with NRI: https://github.com/linuxboot/heads/pull/2025/commits/9b8b9cacdcea4f67c95dcec10b3153fc8c016940 -- You have received this notification because you have either subscribed to it, or are involved in it. To change your notification preferences, please click here: https://ticket.coreboot.org/my/account _______________________________________________ coreboot mailing list -- [email protected] To unsubscribe send an email to [email protected]