From 252457d4b21f46889eebad61d4c0a65331919cec Mon Sep 17 00:00:00 2001 From: Jack Rosenthal Date: Thu, 4 Nov 2021 12:11:58 -0600 Subject: ish: Trim down the release branch In the interest of making long-term branch maintenance incur as little technical debt on us as possible, we should not maintain any files on the branch we are not actually using. This has the added effect of making it extremely clear when merging CLs from the main branch when changes have the possibility to affect us. The follow-on CL adds a convenience script to actually pull updates from the main branch and generate a CL for the update. BUG=b:204206272 BRANCH=ish TEST=make BOARD=arcada_ish && make BOARD=drallion_ish Signed-off-by: Jack Rosenthal Change-Id: I17e4694c38219b5a0823e0a3e55a28d1348f4b18 Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3262038 Reviewed-by: Jett Rink Reviewed-by: Tom Hughes --- README.fmap | 40 ---------------------------------------- 1 file changed, 40 deletions(-) delete mode 100644 README.fmap (limited to 'README.fmap') diff --git a/README.fmap b/README.fmap deleted file mode 100644 index 416d27fe50..0000000000 --- a/README.fmap +++ /dev/null @@ -1,40 +0,0 @@ -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. -- cgit v1.2.1