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BUG=chrome-os-partner:22159 BRANCH=Falco, ToT TEST=manual Let the battery run down. Below 12%, the LED should blink white. Original-Change-Id: I3be2da69a113134456420b1a305e4a0c159c0022 Signed-off-by: Bill Richardson <wfrichar@chromium.org> Signed-off-by: Duncan Laurie <dlaurie@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/167080 (cherry picked from commit fdd33356a31c616457d546d2a1435282e9744355) Change-Id: I7d27ebaea2123b88ea963bf430a5da122a5071b6 Reviewed-on: https://chromium-review.googlesource.com/167139 Commit-Queue: Bill Richardson <wfrichar@chromium.org> Tested-by: Bill Richardson <wfrichar@chromium.org> Reviewed-by: Duncan Laurie <dlaurie@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.