From 94e6ca7aecf8f1b68cd91bfb7eadddd4d4c48d14 Mon Sep 17 00:00:00 2001
From: Rafal Kupiec <belliash@codingworkshop.eu.org>
Date: Tue, 19 Mar 2024 16:50:04 +0100
Subject: [PATCH] Implement BlEnterFirmwareSetup() routine

---
 sdk/xtdk/xtuefi.h      |  3 +++
 xtldr/efiutils.c       | 45 ++++++++++++++++++++++++++++++++++++++++++
 xtldr/includes/xtldr.h |  4 ++++
 3 files changed, 52 insertions(+)

diff --git a/sdk/xtdk/xtuefi.h b/sdk/xtdk/xtuefi.h
index 4d76de7..9aa21d2 100644
--- a/sdk/xtdk/xtuefi.h
+++ b/sdk/xtdk/xtuefi.h
@@ -312,6 +312,9 @@
 #define EFI_TEXT_BOX_FULL_BLOCK                                     0x2588
 #define EFI_TEXT_BOX_LIGHT_BLOCK                                    0x2591
 
+/* EFI OS indication bits */
+#define EFI_OS_INDICATIONS_BOOT_TO_FW_UI                            0x0000000000000001ULL
+
 /* EFI protocols GUIDs */
 #define EFI_BLOCK_IO_PROTOCOL_GUID                         {0x964E5B21, 0x6459, 0x11D2, {0x8E, 0x39, 0x00, 0xA0, 0xC9, 0x69, 0x72, 0x3B}}
 #define EFI_BLOCK_IO2_PROTOCOL_GUID                        {0xA77B2472, 0xE282, 0x4E9F, {0xA2, 0x45, 0xC2, 0xC0, 0xE2, 0x7B, 0xBC, 0xC1}}
diff --git a/xtldr/efiutils.c b/xtldr/efiutils.c
index 7e1a75d..5bda800 100644
--- a/xtldr/efiutils.c
+++ b/xtldr/efiutils.c
@@ -9,6 +9,51 @@
 #include <xtldr.h>
 
 
+/**
+ * Reboots into UEFI firmware setup interface.
+ *
+ * @return This routine returns a status code.
+ *
+ * @since XT 1.0
+ */
+XTCDECL
+EFI_STATUS
+BlEnterFirmwareSetup()
+{
+    EFI_GUID Guid = EFI_GLOBAL_VARIABLE_GUID;
+    PULONGLONG SetupSupport;
+    ULONGLONG Indications;
+    EFI_STATUS Status;
+
+    /* Check if booting into firmware interface is supported */
+    Status = BlGetEfiVariable(&Guid, L"OsIndicationsSupported", (PVOID*)&SetupSupport);
+    if(Status != STATUS_EFI_SUCCESS || !(*SetupSupport & EFI_OS_INDICATIONS_BOOT_TO_FW_UI))
+    {
+        /* Reboot into firmware setup is not supported */
+        BlDebugPrint(L"WARNING: Reboot into firmware setup interface not supported\n");
+        return STATUS_EFI_UNSUPPORTED;
+    }
+
+    /* Get the value of OsIndications variable */
+    Indications = 0;
+    Status = BlGetEfiVariable(&Guid, L"OsIndications", (PVOID)&Indications);
+
+    /* Enable FW setup on next boot */
+    Indications |= EFI_OS_INDICATIONS_BOOT_TO_FW_UI;
+    Status = BlSetEfiVariable(&Guid, L"OsIndications", (PVOID)&Indications, sizeof(Indications));
+    if(Status != STATUS_EFI_SUCCESS)
+    {
+        /* Failed to update OsIndications variable */
+        return Status;
+    }
+
+    /* Reboot into firmware setup */
+    BlRebootSystem();
+
+    /* Must not reach this point, just make the compiler happy */
+    return STATUS_EFI_SUCCESS;
+}
+
 /**
  * Exits EFI boot services.
  *
diff --git a/xtldr/includes/xtldr.h b/xtldr/includes/xtldr.h
index 7225470..cfca6da 100644
--- a/xtldr/includes/xtldr.h
+++ b/xtldr/includes/xtldr.h
@@ -95,6 +95,10 @@ XTCDECL
 VOID
 BlEnableConsoleCursor();
 
+XTCDECL
+EFI_STATUS
+BlEnterFirmwareSetup();
+
 XTCDECL
 EFI_STATUS
 BlEnumerateBlockDevices();