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Dumping before the ADDR bit is cleared also has the effect of clearing the ADDR bit. BUG=chrome-os-partner:22235 TEST=Manual test on peach pit. Keep executing the "battery" command on the EC console while busy running flashrom on the host to read back the EC. See that there's no error produced. BRANCH=pit Signed-off-by: Hung-ying Tyan <tyanh@chromium.org> Change-Id: I10e88a8512f4e9eb90267ef1aca1df5dd214318d Reviewed-on: https://chromium-review.googlesource.com/66930 Reviewed-by: Douglas Anderson <dianders@chromium.org> Commit-Queue: Hung-ying Tyan <tyanh@chromium.org> Tested-by: Hung-ying Tyan <tyanh@chromium.org> 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.