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authorSol Boucher <solb@chromium.org>2015-03-18 12:36:27 -0700
committerStefan Reinauer <stefan.reinauer@coreboot.org>2015-05-13 22:19:59 +0200
commit67a0a864be0e8b81f22ebb9d6f090d77d1da2924 (patch)
tree927c59c4696c7193f590458f5c2e092c8c0ecac0 /util/msrtool/README
parent2591e937e76ccb797d77adbcb667939ca9dfdae5 (diff)
cbfstool: New image format w/ required FMAP and w/o CBFS master header
These new-style firmware images use the FMAP of the root of knowledge about their layout, which allows them to have sections containing raw data whose offset and size can easily be determined at runtime or when modifying or flashing the image. Furthermore, they can even have multiple CBFSes, each of which occupies a different FMAP region. It is assumed that the first entry of each CBFS, including the primary one, will be located right at the start of its region. This means that the bootblock needs to be moved into its own FMAP region, but makes the CBFS master header obsolete because, with the exception of the version and alignment, all its fields are redundant once its CBFS has an entry in the FMAP. The version code will be addressed in a future commit before the new format comes into use, while the alignment will just be defined to 64 bytes in both cbfstool and coreboot itself, since there's almost no reason to ever change it in practice. The version code field and all necessary coreboot changes will come separately. BUG=chromium:470407 TEST=Build panther and nyan_big coreboot.rom and image.bin images with and without this patch, diff their hexdumps, and note that no locations differ except for those that do between subsequent builds of the same codebase. Try working with new-style images: use fmaptool to produce an FMAP section from an fmd file having raw sections and multiple CBFSes, pass the resulting file to cbfstool create -M -F, then try printing its layout and CBFSes' contents, add and remove CBFS files, and read and write raw sections. BRANCH=None Change-Id: I7dd2578d2143d0cedd652fdba5b22221fcc2184a Signed-off-by: Sol Boucher <solb@chromium.org> Original-Commit-Id: 8a670322297f83135b929a5b20ff2bd0e7d2abd3 Original-Change-Id: Ib86fb50edc66632f4e6f717909bbe4efb6c874e5 Original-Signed-off-by: Sol Boucher <solb@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/265863 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-on: http://review.coreboot.org/10135 Tested-by: build bot (Jenkins)
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