From bc744f5893fc4d53275ed26dd8d968011c6a09c1 Mon Sep 17 00:00:00 2001 From: Patrick Rudolph Date: Fri, 17 Apr 2020 16:16:49 +0200 Subject: drivers/smmstore: Implement SMMSTORE version 2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit SMMSTORE version 2 is a complete redesign of the current driver. It is not backwards-compatible with version 1, and only one version can be used at a time. Key features: * Uses a fixed communication buffer instead of writing to arbitrary memory addresses provided by untrusted ring0 code. * Gives the caller full control over the used data format. * Splits the store into smaller chunks to allow fault tolerant updates. * Doesn't provide feedback about the actual read/written bytes, just returns error or success in registers. * Returns an error if the requested operation would overflow the communication buffer. Separate the SMMSTORE into 64 KiB blocks that can individually be read/written/erased. To be used by payloads that implement a FaultTolerant Variable store like TianoCore. The implementation has been tested against EDK2 master. An example EDK2 implementation can be found here: https://github.com/9elements/edk2-1/commit/eb1127744a3a5d5c8ac4e8eb76f07e79c736dbe2 Change-Id: I25e49d184135710f3e6dd1ad3bed95de950fe057 Signed-off-by: Patrick Rudolph Signed-off-by: Christian Walter Reviewed-on: https://review.coreboot.org/c/coreboot/+/40520 Tested-by: build bot (Jenkins) Reviewed-by: Michał Żygowski Reviewed-by: Matt DeVillier --- payloads/libpayload/include/coreboot_tables.h | 1 + 1 file changed, 1 insertion(+) (limited to 'payloads/libpayload/include/coreboot_tables.h') diff --git a/payloads/libpayload/include/coreboot_tables.h b/payloads/libpayload/include/coreboot_tables.h index bf8c0d9303..bfdd21e692 100644 --- a/payloads/libpayload/include/coreboot_tables.h +++ b/payloads/libpayload/include/coreboot_tables.h @@ -79,6 +79,7 @@ enum { CB_TAG_MMC_INFO = 0x0035, CB_TAG_TCPA_LOG = 0x0036, CB_TAG_FMAP = 0x0037, + CB_TAG_SMMSTOREV2 = 0x0039, CB_TAG_CMOS_OPTION_TABLE = 0x00c8, CB_TAG_OPTION = 0x00c9, CB_TAG_OPTION_ENUM = 0x00ca, -- cgit v1.2.3