From c36b13a6c29cf8f51a1b6f3ad8b8050e42879649 Mon Sep 17 00:00:00 2001
From: Fabian Ruhland <ruhland@hhu.de>
Date: Fri, 2 Aug 2024 21:07:27 +0200
Subject: [PATCH] Dirty fix for multiple ACPIv2 tags occurring on real hardware

---
 towboot/src/boot/config_tables.rs | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/towboot/src/boot/config_tables.rs b/towboot/src/boot/config_tables.rs
index f16517d..2461a29 100644
--- a/towboot/src/boot/config_tables.rs
+++ b/towboot/src/boot/config_tables.rs
@@ -11,6 +11,8 @@ use uefi::table::cfg::{
     SMBIOS3_GUID,
 };
 
+static mut RSDP_V2_SET: bool = false;
+
 /// Go through all of the configuration tables.
 /// Some of them are interesting for Multiboot2.
 pub(super) fn parse_for_multiboot(
@@ -49,12 +51,17 @@ fn handle_acpi(table: &ConfigTableEntry, info_builder: &mut InfoBuilder) {
             rsdp.revision(), rsdp.rsdt_address(),
         );
     } else {
-        info_builder.set_rsdp_v2(
-            rsdp.signature(), rsdp.checksum(),
-            rsdp.oem_id().as_bytes()[0..6].try_into().unwrap(),
-            rsdp.revision(), rsdp.rsdt_address(), rsdp.length(),
-            rsdp.xsdt_address(), rsdp.ext_checksum(),
-        );
+        unsafe {
+            if !RSDP_V2_SET {
+                info_builder.set_rsdp_v2(
+                    rsdp.signature(), rsdp.checksum(),
+                    rsdp.oem_id().as_bytes()[0..6].try_into().unwrap(),
+                    rsdp.revision(), rsdp.rsdt_address(), rsdp.length(),
+                    rsdp.xsdt_address(), rsdp.ext_checksum(),
+                );
+                RSDP_V2_SET = true;
+            }
+        }
     }
 }