linux-t2-patches/2010-efi-libstub-add-support-for-the-apple_set_os-protoco.patch

From 6adb501c697cd0e3246e75237ee8e43eb5a92cc3 Mon Sep 17 00:00:00 2001
From: Kerem Karabay <kekrby@gmail.com>
Date: Thu, 23 Nov 2023 18:58:51 +0530
Subject: [PATCH] efi: libstub: add support for the apple_set_os protocol

On dual GPU EFI Macs, the EFI stub needs to report that it is booting
macOS in order to prevent the firmware from disabling the iGPU.

See also this patch for GRUB by Andreas Heider <andreas@heider.io>:
https://lists.gnu.org/archive/html/grub-devel/2013-12/msg00442.html
---
 .../admin-guide/kernel-parameters.txt         |  2 ++
 .../firmware/efi/libstub/efi-stub-helper.c    |  3 +++
 drivers/firmware/efi/libstub/efistub.h        | 14 ++++++++++
 drivers/firmware/efi/libstub/x86-stub.c       | 27 +++++++++++++++++++
 include/linux/efi.h                           |  1 +
 5 files changed, 47 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 41644336e..cbd4697a5 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -399,6 +399,8 @@
 			      useful so that a dump capture kernel won't be
 			      shot down by NMI
 
+	apple_set_os	[KNL] Report that macOS is being booted to the firmware
+
 	autoconf=	[IPV6]
 			See Documentation/networking/ipv6.rst.
 
diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
index bfa30625f..3d99acc1a 100644
--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -19,6 +19,7 @@
 bool efi_nochunk;
 bool efi_nokaslr = !IS_ENABLED(CONFIG_RANDOMIZE_BASE);
 bool efi_novamap;
+bool efi_apple_set_os;
 
 static bool efi_noinitrd;
 static bool efi_nosoftreserve;
@@ -73,6 +74,8 @@ efi_status_t efi_parse_options(char const *cmdline)
 			efi_loglevel = CONSOLE_LOGLEVEL_QUIET;
 		} else if (!strcmp(param, "noinitrd")) {
 			efi_noinitrd = true;
+		} else if (!strcmp(param, "apple_set_os")) {
+			efi_apple_set_os = true;
 		} else if (IS_ENABLED(CONFIG_X86_64) && !strcmp(param, "no5lvl")) {
 			efi_no5lvl = true;
 		} else if (!strcmp(param, "efi") && val) {
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 212687c30..21b414d09 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -38,6 +38,7 @@ extern bool efi_nochunk;
 extern bool efi_nokaslr;
 extern int efi_loglevel;
 extern bool efi_novamap;
+extern bool efi_apple_set_os;
 
 extern const efi_system_table_t *efi_system_table;
 
@@ -825,6 +826,19 @@ union apple_properties_protocol {
 	} mixed_mode;
 };
 
+typedef struct apple_set_os_protocol apple_set_os_protocol_t;
+
+struct apple_set_os_protocol {
+	u64 version;
+	efi_status_t (__efiapi *set_os_version) (const char *);
+	efi_status_t (__efiapi *set_os_vendor) (const char *);
+	struct {
+		u32 version;
+		u32 set_os_version;
+		u32 set_os_vendor;
+	} mixed_mode;
+};
+
 typedef u32 efi_tcg2_event_log_format;
 
 #define INITRD_EVENT_TAG_ID 0x8F3B22ECU
diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 70b325a2f..2131f8543 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -223,6 +223,30 @@ static void retrieve_apple_device_properties(struct boot_params *boot_params)
 	}
 }
 
+static void apple_set_os(void)
+{
+	efi_guid_t guid = APPLE_SET_OS_PROTOCOL_GUID;
+	apple_set_os_protocol_t *set_os;
+	efi_status_t status;
+
+	status = efi_bs_call(locate_protocol, &guid, NULL, (void **)&set_os);
+	if (status != EFI_SUCCESS)
+		return;
+
+	if (efi_table_attr(set_os, version) >= 2) {
+		status = efi_fn_call(set_os, set_os_vendor, "Apple Inc.");
+		if (status != EFI_SUCCESS)
+			efi_err("Failed to set OS vendor via apple_set_os\n");
+	}
+
+	/* The version being set doesn't seem to matter */
+	if (efi_table_attr(set_os, version) > 0) {
+		status = efi_fn_call(set_os, set_os_version, "Mac OS X 10.9");
+		if (status != EFI_SUCCESS)
+			efi_err("Failed to set OS version via apple_set_os\n");
+	}
+}
+
 efi_status_t efi_adjust_memory_range_protection(unsigned long start,
 						unsigned long size)
 {
@@ -321,6 +345,9 @@ static void setup_quirks(struct boot_params *boot_params)
 	if (IS_ENABLED(CONFIG_APPLE_PROPERTIES) &&
 	    !memcmp(efistub_fw_vendor(), apple, sizeof(apple)))
 		retrieve_apple_device_properties(boot_params);
+
+	if (efi_apple_set_os)
+		apple_set_os();
 }
 
 /*
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 80b21d1c6..f1e58e027 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -387,6 +387,7 @@ void efi_native_runtime_setup(void);
 #define EFI_MEMORY_ATTRIBUTES_TABLE_GUID	EFI_GUID(0xdcfa911d, 0x26eb, 0x469f,  0xa2, 0x20, 0x38, 0xb7, 0xdc, 0x46, 0x12, 0x20)
 #define EFI_CONSOLE_OUT_DEVICE_GUID		EFI_GUID(0xd3b36f2c, 0xd551, 0x11d4,  0x9a, 0x46, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d)
 #define APPLE_PROPERTIES_PROTOCOL_GUID		EFI_GUID(0x91bd12fe, 0xf6c3, 0x44fb,  0xa5, 0xb7, 0x51, 0x22, 0xab, 0x30, 0x3a, 0xe0)
+#define APPLE_SET_OS_PROTOCOL_GUID		EFI_GUID(0xc5c5da95, 0x7d5c, 0x45e6,  0xb2, 0xf1, 0x3f, 0xd5, 0x2b, 0xb1, 0x00, 0x77)
 #define EFI_TCG2_PROTOCOL_GUID			EFI_GUID(0x607f766c, 0x7455, 0x42be,  0x93, 0x0b, 0xe4, 0xd7, 0x6d, 0xb2, 0x72, 0x0f)
 #define EFI_LOAD_FILE_PROTOCOL_GUID		EFI_GUID(0x56ec3091, 0x954c, 0x11d2,  0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b)
 #define EFI_LOAD_FILE2_PROTOCOL_GUID		EFI_GUID(0x4006c0c1, 0xfcb3, 0x403e,  0x99, 0x6d, 0x4a, 0x6c, 0x87, 0x24, 0xe0, 0x6d)
-- 
2.34.1