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0e3ff013cc
Fixed a potential bug in accelerometer initialization that could result in failing to write the desired accelereometer settings. Before writing the desired settings, we first send a command to perform a software reset. While waiting for software reset to complete, if we have an I2C error, then we could interpret this as software reset complete and go on to write the accelerometer settings before the reset has actually completed. BUG=none BRANCH=rambi TEST=Code inspection. I haven't actually seen this bug, I just saw the potential for it. Change-Id: I78757106291ffbaeff27f94aa6f74c9cea81e0b9 Signed-off-by: Alec Berg <alecaberg@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/189064 (cherry picked from commit 521a99e38428fcfe928616f4932b5d1167e2f6cb) Reviewed-on: https://chromium-review.googlesource.com/189233 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.