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The bolt board has the PP1050 regulator's pgood output connected to VCCST_PWRGD on the chipset. However, that is inappropriate because VCCST_PWRGD is the signal used when the 1.05V rail is good when transitioning to S0. The PP1050 regulator needs to be up while in S5 to supply the 1.05V suspend rail. To work around this mismatch, the PP1050_PGOOD signal which is routed to the EC needs to be changed to an open-drain output. It's driven low until the transition to S0 in order to properly sequence the chip. BUG=chrome-os-partner:20372 BRANCH=None TEST=Built and booted on handful of boards. Change-Id: Ic85eab8f295f6e76d9b33f440e68c82096976683 Signed-off-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: https://gerrit.chromium.org/gerrit/66821 Reviewed-by: Bill Richardson <wfrichar@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.