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e2f851aae2
Changes somewhere in the recent past have caused I2C operations to
consume more stack space. The current failure mode is that after some
debug command or infrequent battery operation, the system fails.
Clean up and enable stack overflow detection by default, and add a
debug command (disabled by default) to verify overflow detection
works.
This adds several instructions to each context switch, but it's still
fairly inexpensive, and represents only a few percent increase in the
size of svc_handler(). That's better than silent failures.
BUG=chrome-os-partner:23938
BRANCH=none
TEST=Enable CONFIG_CMD_STACKOVERFLOW, then run the 'stackoverflow' command.
This should cause a stack overflow to be detected in the CONSOLE task.
Change-Id: I9303aee5bd9318f1d92838b399d15fb8f6a2bbf9
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/176113
Reviewed-by: Bill Richardson <wfrichar@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.