From 45d382dcf9d7d7a31b4459e5e47beda630946b49 Mon Sep 17 00:00:00 2001
From: Daniel Maslowski <info@orangecms.org>
Date: Mon, 28 Oct 2024 04:29:56 +0100
Subject: [PATCH] add alternative header ending signature

This is found in ASRock firmware images, e.g. A520M-HVS A52MIX_2.73.
Also seen in coreboot 3rd_party/blobs/mainboard/, and used in Fiano:
https://github.com/linuxboot/fiano/blob/d844cd98141518f41b3e4012bcf419984074a2b4/pkg/amd/apcb/internal.go#L16

Fixes <https://github.com/oxidecomputer/amd-apcb/issues/142>.

Signed-off-by: Daniel Maslowski <info@orangecms.org>
---
 src/apcb.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/apcb.rs b/src/apcb.rs
index 4b02e82..4720f22 100644
--- a/src/apcb.rs
+++ b/src/apcb.rs
@@ -1268,8 +1268,12 @@ impl<'a> Apcb<'a> {
                     "V3_HEADER_EXT::data_offset",
                 ));
             }
+            // NOTE: The AMD docs for Turin, Genoa, Milan and Rome say `BCPA`,
+            // i.e., `APCB` backwards. Some vendors are using `BCBA` instead,
+            // e.g., ASRock and coreboot (`3rdparty/blobs/mainboard/`).
             if !options.check_signature_ending
                 || value.signature_ending == *b"BCPA"
+                || value.signature_ending == *b"BCBA"
             {
             } else {
                 return Err(Error::FileSystem(