From 508fd27e92d55be05185a462dac3e362211bfd7e Mon Sep 17 00:00:00 2001
From: Rafal Kupiec <belliash@codingworkshop.eu.org>
Date: Wed, 31 Jan 2024 16:25:43 +0100
Subject: [PATCH] Implement BlGetConfigurationTable() routine

---
 sdk/xtdk/bltypes.h     |  2 ++
 xtldr/efiutils.c       | 37 +++++++++++++++++++++++++++++++++++++
 xtldr/includes/xtldr.h |  5 +++++
 xtldr/protocol.c       |  1 +
 4 files changed, 45 insertions(+)

diff --git a/sdk/xtdk/bltypes.h b/sdk/xtdk/bltypes.h
index 91b4220..21b8fa0 100644
--- a/sdk/xtdk/bltypes.h
+++ b/sdk/xtdk/bltypes.h
@@ -76,6 +76,7 @@ typedef EFI_STATUS (*PBL_FRAMEBUFFER_GET_DISPLAY_INFORMATION)(OUT PXTBL_FRAMEBUF
 typedef EFI_STATUS (*PBL_FRAMEBUFFER_INITIALIZE)();
 typedef EFI_STATUS (*PBL_FREE_PAGES)(IN ULONGLONG Size, IN EFI_PHYSICAL_ADDRESS Memory);
 typedef EFI_STATUS (*PBL_FREE_POOL)(IN PVOID Memory);
+typedef EFI_STATUS (*PBL_GET_CONFIGURATION_TABLE)(IN PEFI_GUID TableGuid, OUT PVOID *Table);
 typedef VOID (*PBL_GET_MAPPINGS_COUNT)(IN PXTBL_PAGE_MAPPING PageMap, OUT PULONG NumberOfMappings);
 typedef EFI_STATUS (*PBL_GET_MEMORY_MAP)(OUT PEFI_MEMORY_MAP MemoryMap);
 typedef PLIST_ENTRY (*PBL_GET_MODULES_LIST)();
@@ -354,6 +355,7 @@ typedef struct _XTBL_LOADER_PROTOCOL
     struct
     {
         PBL_EXIT_BOOT_SERVICES ExitBootServices;
+        PBL_GET_CONFIGURATION_TABLE GetConfigurationTable;
         PBL_GET_SECURE_BOOT_STATUS GetSecureBootStatus;
         PBL_LOAD_EFI_IMAGE LoadEfiImage;
         PBL_POWER_SYSTEM RebootSystem;
diff --git a/xtldr/efiutils.c b/xtldr/efiutils.c
index d51219f..50d8fb4 100644
--- a/xtldr/efiutils.c
+++ b/xtldr/efiutils.c
@@ -66,6 +66,43 @@ BlExitBootServices()
     return Status;
 }
 
+/**
+ * Gets the address of a reqested system configuration table.
+ *
+ * @param TableGuid
+ *        Supplies a GUID of the configuration table.
+ *
+ * @param Table
+ *        Supplies a pointer to the memory area where the table address will be stored.
+ *
+ * @return This routine returns a status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlGetConfigurationTable(IN PEFI_GUID TableGuid,
+                        OUT PVOID *Table)
+{
+    SIZE_T Index;
+
+    /* Iterate through all system configuration tables */
+    for(Index = 0; Index < EfiSystemTable->NumberOfTableEntries; Index++)
+    {
+        /* Check if this table matches requested table */
+        if(RtlCompareGuids((PGUID)&(EfiSystemTable->ConfigurationTable[Index].VendorGuid), (PGUID)TableGuid))
+        {
+            /* Found requested table, return success */
+            *Table = EfiSystemTable->ConfigurationTable[Index].VendorTable;
+            return STATUS_EFI_SUCCESS;
+        }
+    }
+
+    /* Table not found */
+    *Table = NULL;
+    return STATUS_EFI_NOT_FOUND;
+}
+
 /**
  * Checks whether SecureBoot is enabled or not.
  *
diff --git a/xtldr/includes/xtldr.h b/xtldr/includes/xtldr.h
index 2221809..84ab048 100644
--- a/xtldr/includes/xtldr.h
+++ b/xtldr/includes/xtldr.h
@@ -130,6 +130,11 @@ XTCDECL
 PWCHAR
 BlGetConfigValue(IN CONST PWCHAR ConfigName);
 
+XTCDECL
+EFI_STATUS
+BlGetConfigurationTable(IN PEFI_GUID TableGuid,
+                        OUT PVOID *Table);
+
 XTCDECL
 EFI_STATUS
 BlGetEfiPath(IN PWCHAR SystemPath,
diff --git a/xtldr/protocol.c b/xtldr/protocol.c
index 7b07c26..26ddee4 100644
--- a/xtldr/protocol.c
+++ b/xtldr/protocol.c
@@ -653,6 +653,7 @@ BlpInstallXtLoaderProtocol()
     BlpLdrProtocol.Tui.DisplayProgressDialog = BlDisplayProgressDialog;
     BlpLdrProtocol.Tui.UpdateProgressBar = BlUpdateProgressBar;
     BlpLdrProtocol.Util.ExitBootServices = BlExitBootServices;
+    BlpLdrProtocol.Util.GetConfigurationTable = BlGetConfigurationTable;
     BlpLdrProtocol.Util.GetSecureBootStatus = BlGetSecureBootStatus;
     BlpLdrProtocol.Util.LoadEfiImage = BlLoadEfiImage;
     BlpLdrProtocol.Util.RebootSystem = BlRebootSystem;