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stm32l100 is mostly identical to stm32l151, excepted that the RAM is smaller (10kB instead of 16kB for the RB SKU), the EEPROM is smaller, there is no touch capability (but we are not using those 2 features). So, in the new stm32l100 variant configuration, we adjust the memory size to 10kB and keep the regular UART RX buffer size (512 B) rather than putting a 2kB buffer to fit in the new constraints. Signed-off-by: Vincent Palatin <vpalatin@chromium.org> BRANCH=none BUG=none TEST=run on discovery board reworked with stm32l100rct6 and Nyan reworked with stm32l100rbt6. Change-Id: Ifd78f59a102b3079f0f794af8058211dc724153d Reviewed-on: https://chromium-review.googlesource.com/173632 Reviewed-by: Randall Spangler <rspangler@chromium.org> Reviewed-by: Vic Yang <victoryang@chromium.org> Tested-by: Vincent Palatin <vpalatin@chromium.org> Commit-Queue: Vincent Palatin <vpalatin@chromium.org> Commit-Queue: David James <davidjames@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.