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9de183a5d6
This works around an issue where LCDVCC falls too slowly. The impact
is to slow shutdown by 7 ms, which isn't noticeable to the user.
BUG=chrome-os-partner:26561
BRANCH=rambi
TEST=shut down rambi; still shuts down, and ~7 ms more time is spent
in S0->S3 state.
before:
[429.933010 power state 3 = S0, in 0x043f]
[429.933240 power state 7 = S0->S3, in 0x043f]
[429.933614 power state 2 = S3, in 0x042b]
[429.934013 power state 8 = S3->S5, in 0x0428]
after:
[20.355975 power state 3 = S0, in 0x003f]
[20.356194 power state 7 = S0->S3, in 0x003f]
[20.363957 power state 2 = S3, in 0x002c]
[20.364179 power state 8 = S3->S5, in 0x002c]
[20.364877 power state 1 = S5, in 0x0008]
Change-Id: Ie843bdcf740f3dbc1b866a0356cea2a8b42d4194
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/189092
Reviewed-by: Aaron Durbin <adurbin@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.