diff options
author | Aaron Durbin <adurbin@chromium.org> | 2015-04-01 09:27:44 -0500 |
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committer | Aaron Durbin <adurbin@google.com> | 2015-04-07 00:20:13 +0200 |
commit | f34ea5f6609c23db33b6a6b7c31c67c6214efae4 (patch) | |
tree | 845a2726447cf234c1edfca9b6cf9780f89e1ae5 /documentation | |
parent | f78a09b60c4ce24e2455615722dd6ed8e2ba85e2 (diff) |
documentation: define downstream data consumption rules
It's important to document what data is available for
downstream consumption by the OS and payloads. Provide
details/directions on what is available.
Change-Id: Icafb6e9f59462ad19cf6a641046c6efc36f138f0
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/9194
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marc.jones@se-eng.com>
Diffstat (limited to 'documentation')
-rw-r--r-- | documentation/abi-data-consumption.txt | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/documentation/abi-data-consumption.txt b/documentation/abi-data-consumption.txt new file mode 100644 index 0000000000..81442e7170 --- /dev/null +++ b/documentation/abi-data-consumption.txt @@ -0,0 +1,22 @@ +This text describes the ABI coreboot presents to downstream users. Such +users are payloads and/or operating systems. Therefore, this text serves +at what can be relied on for downstream consumption. Anything not explicitly +listed as consumable is subject to change without notice. + +Background and Usage + +coreboot passes information to downstream users using coreboot tables. These +table definitions can be found in src/include/boot/coreboot_tables.h and +payloads/libpayload/include/coreboot_tables.h respectively within coreboot +and libpayload. One of the most vital and important pieces of information +found within these tables is the memory map of the system indicating +available and reserved memory. + +In 2009 cbmem was added to coreboot. The "CBMEM high table memory manager" +serves a way for coreboot to bookkeep its own internal data. While some +of this data may be exposed through the coreboot tables the data structures +used to manage the data within the cbmem area is subject to change. + +Provided the above, if one needs a piece of data exposed to the OS +or payload it should reside within the coreboot tables. If it isn't there +then a code change will be required to add it to the coreboot tables. |