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10bd1db6d7
Changed the low power idle task to use the low speed clock in deep sleep. The low power idle task is currently only enabled for Peppy, Slippy, and Falco. This change decreases power consumption when the AP is not running. Note that the low speed clock is slow enough that the JTAG cannot be used and the EC console UART cannot be used. To work around that, this commit detects when the JTAG is in use and when the EC console is in use, and will not use the low speed clock if either is in use. The JTAG in use never clears after being set and the console in use clears after a fixed timeout period. BUG=None BRANCH=None TEST=Passes all unit tests. Tested that the EC console works when in deep sleep. Tested that it is possible to run flash_ec when in deep sleep and using the low speed clock. Change-Id: Ia65997eb8e607a5df9b2c7d68e4826bfb1e0194c Signed-off-by: Alec Berg <alecaberg@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/173326 Reviewed-by: Vincent Palatin <vpalatin@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.