diff mbox series

efi: libstub: add support for the apple_set_os protocol

Message ID EBE51900-DA87-4113-B389-80B9C9160F0F@live.com
State New
Headers show
Series efi: libstub: add support for the apple_set_os protocol | expand

Commit Message

Aditya Garg June 30, 2024, 4:42 a.m. UTC
From: Aditya Garg <gargaditya08@live.com>

Commit 0c18184de990 brought support for T2 Macs in apple-gmux. But in order to
use dual GPU, the integrated GPU has to be enabled. On such 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.

This patch is also applicable for some non T2 Intel Macs.

Based on this patch for GRUB by Andreas Heider <andreas@heider.io>:
https://lists.gnu.org/archive/html/grub-devel/2013-12/msg00442.html

Credits also goto Kerem Karabay <kekrby@gmail.com> for helping porting the patch
to the Linux kernel.

Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
 .../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 mbox series

Patch

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 (IS_ENABLED(CONFIG_ARCH_HAS_MEM_ENCRYPT) &&
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 int efi_loglevel;
 extern int efi_mem_encrypt;
 extern bool efi_novamap;
+extern bool efi_apple_set_os;
 extern const efi_system_table_t *efi_system_table;
 
 typedef union efi_dxe_services_table efi_dxe_services_table_t;
@@ -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_TCG2_FINAL_EVENTS_TABLE_GUID	EFI_GUID(0x1e2ed096, 0x30e2, 0x4254,  0xbd, 0x89, 0x86, 0x3b, 0xbe, 0xf8, 0x23, 0x25)
 #define EFI_LOAD_FILE_PROTOCOL_GUID		EFI_GUID(0x56ec3091, 0x954c, 0x11d2,  0x8e, 0x3f, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b)