mirror of
https://github.com/Telecominfraproject/OpenCellular.git
synced 2025-12-27 18:25:05 +00:00
a35bfd69e9
Previously, it could only read 8 or 16 bit values BUG=chrome-os-partner:26191 BRANCH=rambi TEST=manual Counted string for battery manufacturer name: > i2cxfer rlen 0 0x16 0x20 16 Data: 0653696d706c6fe1e1e1e1e1e1e1e1e1 Read lifetime data block 1 (also tests 16-bit writes) > i2cxfer w16 0 0x16 0 0x60 > i2cxfer rlen 0 0x16 0x23 32 Data: 20d2d2d2d2948700000d0a0a060a000000020000000000000000000000000000 Read lifetime data block 2 > i2cxfer w16 0 0x16 0 0x61 > i2cxfer rlen 0 0x16 0x23 27 Data: 1b0000000000010200010c02000201000100000300002008082009 8 and 16 bit reads still work > i2cxfer r 0 0x16 0x23 0x1b [27] > i2cxfer r16 0 0x16 0x23 0x001b [27] Change-Id: Ibba5aced60c0b2de04c3f86cf5fd2ab3db1b6308 Signed-off-by: Randall Spangler <rspangler@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/188379 Reviewed-by: Alec Berg <alecaberg@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.