4d8b843d37
In order to be closer to the Linux kernel source tree structure, rename documentation to Documentation. Change-Id: I8690f666638ef352d201bd3c3dc1923b0d24cb12 Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org> Reviewed-on: http://review.coreboot.org/10110 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com>
22 lines
1.2 KiB
Text
22 lines
1.2 KiB
Text
This text describes the ABI coreboot presents to downstream users. Such
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users are payloads and/or operating systems. Therefore, this text serves
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at what can be relied on for downstream consumption. Anything not explicitly
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listed as consumable is subject to change without notice.
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Background and Usage
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coreboot passes information to downstream users using coreboot tables. These
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table definitions can be found in src/include/boot/coreboot_tables.h and
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payloads/libpayload/include/coreboot_tables.h respectively within coreboot
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and libpayload. One of the most vital and important pieces of information
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found within these tables is the memory map of the system indicating
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available and reserved memory.
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In 2009 cbmem was added to coreboot. The "CBMEM high table memory manager"
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serves a way for coreboot to bookkeep its own internal data. While some
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of this data may be exposed through the coreboot tables the data structures
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used to manage the data within the cbmem area is subject to change.
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Provided the above, if one needs a piece of data exposed to the OS
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or payload it should reside within the coreboot tables. If it isn't there
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then a code change will be required to add it to the coreboot tables.
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