From 293c5984211d6ed71b8ed3eb182368e9af3da339 Mon Sep 17 00:00:00 2001
From: Alon Livne <2005alonlivne@gmail.com>
Date: Sat, 4 Oct 2025 13:29:26 +0300
Subject: [PATCH] fix: add runtime services descs to usable memory types

The OS can use runtime services so they have to be stored and switched as well.
This is especially true since the OS holds physical pointers to the
runtime services, which are loaded at different physical addresses every
boot. If they weren't switched, then the OS would hold invalid physical
pointers.
---
 uefi/core_header_utils.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/uefi/core_header_utils.c b/uefi/core_header_utils.c
index b1a034a..da98702 100644
--- a/uefi/core_header_utils.c
+++ b/uefi/core_header_utils.c
@@ -59,13 +59,14 @@ static err_t fill_disk_pci(void) {
 }
 
 /**
- * According to the UEFI specs (table 7.6 in section 7.2), all of the following memory types can be used
- * by the OS as RAM after full initialization.
+ * A whitelist of memory descriptor types which will be stored and switched by core.
+ * They represent descriptors that the OS uses. These either include descriptor types that the OS can freely use as
+ * memory (see table 7.6 in section 7.2 of the UEFI specs), or descriptor types which the OS uses implicitly (such as
+ * runtime services).
  */
 static const EFI_MEMORY_TYPE g_usable_memory_types[] = {
-  EfiLoaderCode,         EfiLoaderData,        EfiBootServicesCode, EfiBootServicesData,
-  EfiConventionalMemory, EfiACPIReclaimMemory, EfiPersistentMemory,
-};
+  EfiLoaderCode,        EfiLoaderData,       EfiBootServicesCode,    EfiBootServicesData,   EfiConventionalMemory,
+  EfiACPIReclaimMemory, EfiPersistentMemory, EfiRuntimeServicesCode, EfiRuntimeServicesData};
 
 /**
  * Returns whether a given memory descriptor can be used by the OS as RAM.