From 9f9f7a23d9f52a4278150390bd44c7d9496c160f Mon Sep 17 00:00:00 2001 From: Jonathan Neuschäfer Date: Sun, 8 Apr 2018 15:54:47 +0200 Subject: Documentation: Convert abi-data-consumption.txt to Markdown MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This will help static site generators that can turn Markdown into HTML but can't easily turn plain text into HTML. Change-Id: Id186db140503f3c2759d579b18476fff021988c8 Signed-off-by: Jonathan Neuschäfer Reviewed-on: https://review.coreboot.org/25559 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi Reviewed-by: Paul Menzel --- Documentation/abi-data-consumption.md | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 Documentation/abi-data-consumption.md (limited to 'Documentation/abi-data-consumption.md') diff --git a/Documentation/abi-data-consumption.md b/Documentation/abi-data-consumption.md new file mode 100644 index 0000000000..962f33eac5 --- /dev/null +++ b/Documentation/abi-data-consumption.md @@ -0,0 +1,24 @@ +# ABI data consumption + +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. -- cgit v1.2.3