mirror of
https://github.com/Telecominfraproject/OpenCellular.git
synced 2026-01-07 16:11:43 +00:00
58d8a739b2
Previously we could get into some pretty bad situtation around frequency changes. Specifically: * If the freq change code exectued during a transaction then it would get all messed up. * If the freq change notifier executed during a transaction then we'd reset the bus midway through transaction. Badness. BRANCH=pit BUG=chrome-os-partner:22093 TEST=With all patches together: - on AP: suspend_stress_test - on EC: battery 10000 50 Change-Id: I24be29d459fe229a6278829a7c03c1e102358e8c Signed-off-by: Doug Anderson <dianders@chromium.org> Previous-Reviewed-on: https://chromium-review.googlesource.com/167102 (cherry picked from commit deab2433c13bc3b3bb75cd33c12dad633ba6a42a) Reviewed-on: https://chromium-review.googlesource.com/167149 Reviewed-by: Randall Spangler <rspangler@chromium.org>
In the most general case, the flash layout looks something like this: +---------------------+ | Reserved for EC use | +---------------------+ +---------------------+ | Vblock B | +---------------------+ | RW firmware B | +---------------------+ +---------------------+ | Vblock A | +---------------------+ | RW firmware A | +---------------------+ +---------------------+ | FMAP | +---------------------+ | Public root key | +---------------------+ | Read-only firmware | +---------------------+ BIOS firmware (and kernel) put the vblock info at the start of each image where it's easy to find. The Blizzard EC expects the firmware vector table to come first, so we have to put the vblock at the end. This means we have to know where to look for it, but that's built into the FMAP and the RO firmware anyway, so that's not an issue. The RO firmware doesn't need a vblock of course, but it does need some reserved space for vboot-related things. Using SHA256/RSA4096, the vblock is 2468 bytes (0x9a4), while the public root key is 1064 bytes (0x428) and the current FMAP is 644 bytes (0x284). If we reserve 4K at the top of each FW image, that should give us plenty of room for vboot-related stuff.