mirror of
https://github.com/Telecominfraproject/OpenCellular.git
synced 2025-12-27 18:25:05 +00:00
6bdc699401
This command wedges the I2C bus by writing part of a byte to or reading part of the response from the slave device. To enabled the wedge command you must define CONFIG_CMD_I2CWEDGE and you must define I2C_PORT_HOST, the i2c port to use the wedge command. BUG=chrome-os-partner:19286 TEST=Manual test on peach pit, spring, and glimmer. Define config in board.h to enable the command: On the EC console, execute the following "i2cwedge" command i2cwedge 0x90 0 1 (wedge write) or i2cwedge 0x90 0 2 (wedge read) and then "battery". Observe that the command reports an error. Similarly, execute i2cwedge 0x90 0 5 (wedge write + reboot) or i2cwedge 0x90 0 6 (wedge read + reboot) on the EC console and observe a reboot. Then execute "battery" and observe that the command works properly. BRANCH=none Change-Id: I10ccb21b047df907a4dfdbd84c0f582cfa2d939a Signed-off-by: Hung-ying Tyan <tyanh@chromium.org> Signed-off-by: Doug Anderson <dianders@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/66389 Tested-by: Alec Berg <alecaberg@chromium.org> Reviewed-by: Randall Spangler <rspangler@chromium.org> Commit-Queue: 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.