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Now that U-Boot and kernel can properly talk to the EC in pit, there's no reason to hack all the FETs on. We only need to turn on FET4 which enables SD card booting. We'll leave the old "all fets on" hack there for "puppy", though. Apparently that still needs it? BRANCH=pit BUG=chrome-os-partner:21975 TEST=Boot up and see LCD turn on. TEST=Cold reset while holding recovery and can boot from SD card. Change-Id: Iae96375ac7bd1a9eed8243367332cf003b62c48d Signed-off-by: Doug Anderson <dianders@chromium.org> Reviewed-on: https://gerrit.chromium.org/gerrit/66127 Reviewed-by: Katie Roberts-Hoffman <katierh@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.