diff --git a/lib/linux/efi.h b/lib/linux/efi.h
new file mode 100644
index 0000000..bb4601b
--- /dev/null
+++ b/lib/linux/efi.h
@@ -0,0 +1,518 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Relevant definitions from linux/efi.h. */
+
+#ifndef __LINUX_UEFI_H
+#define __LINUX_UEFI_H
+
+#define BITS_PER_LONG 64
+
+#define EFI_SUCCESS		0
+#define EFI_LOAD_ERROR		( 1 | (1UL << (BITS_PER_LONG-1)))
+#define EFI_INVALID_PARAMETER	( 2 | (1UL << (BITS_PER_LONG-1)))
+#define EFI_UNSUPPORTED		( 3 | (1UL << (BITS_PER_LONG-1)))
+#define EFI_BAD_BUFFER_SIZE	( 4 | (1UL << (BITS_PER_LONG-1)))
+#define EFI_BUFFER_TOO_SMALL	( 5 | (1UL << (BITS_PER_LONG-1)))
+#define EFI_NOT_READY		( 6 | (1UL << (BITS_PER_LONG-1)))
+#define EFI_DEVICE_ERROR	( 7 | (1UL << (BITS_PER_LONG-1)))
+#define EFI_WRITE_PROTECTED	( 8 | (1UL << (BITS_PER_LONG-1)))
+#define EFI_OUT_OF_RESOURCES	( 9 | (1UL << (BITS_PER_LONG-1)))
+#define EFI_NOT_FOUND		(14 | (1UL << (BITS_PER_LONG-1)))
+#define EFI_TIMEOUT		(18 | (1UL << (BITS_PER_LONG-1)))
+#define EFI_ABORTED		(21 | (1UL << (BITS_PER_LONG-1)))
+#define EFI_SECURITY_VIOLATION	(26 | (1UL << (BITS_PER_LONG-1)))
+
+typedef unsigned long efi_status_t;
+typedef u8 efi_bool_t;
+typedef u16 efi_char16_t;		/* UNICODE character */
+typedef u64 efi_physical_addr_t;
+typedef void *efi_handle_t;
+
+#define __efiapi __attribute__((ms_abi))
+
+/*
+ * The UEFI spec and EDK2 reference implementation both define EFI_GUID as
+ * struct { u32 a; u16; b; u16 c; u8 d[8]; }; and so the implied alignment
+ * is 32 bits not 8 bits like our guid_t. In some cases (i.e., on 32-bit ARM),
+ * this means that firmware services invoked by the kernel may assume that
+ * efi_guid_t* arguments are 32-bit aligned, and use memory accessors that
+ * do not tolerate misalignment. So let's set the minimum alignment to 32 bits.
+ *
+ * Note that the UEFI spec as well as some comments in the EDK2 code base
+ * suggest that EFI_GUID should be 64-bit aligned, but this appears to be
+ * a mistake, given that no code seems to exist that actually enforces that
+ * or relies on it.
+ */
+typedef struct {
+	u8 b[16];
+} guid_t __attribute__((aligned(__alignof__(u32))));
+typedef guid_t efi_guid_t;
+
+#define EFI_GUID(a, b, c, d...) (efi_guid_t){ {					\
+	(a) & 0xff, ((a) >> 8) & 0xff, ((a) >> 16) & 0xff, ((a) >> 24) & 0xff,	\
+	(b) & 0xff, ((b) >> 8) & 0xff,						\
+	(c) & 0xff, ((c) >> 8) & 0xff, d } }
+
+/*
+ * Generic EFI table header
+ */
+typedef	struct {
+	u64 signature;
+	u32 revision;
+	u32 headersize;
+	u32 crc32;
+	u32 reserved;
+} efi_table_hdr_t;
+
+/*
+ * Memory map descriptor:
+ */
+
+/* Memory types: */
+#define EFI_RESERVED_TYPE		 0
+#define EFI_LOADER_CODE			 1
+#define EFI_LOADER_DATA			 2
+#define EFI_BOOT_SERVICES_CODE		 3
+#define EFI_BOOT_SERVICES_DATA		 4
+#define EFI_RUNTIME_SERVICES_CODE	 5
+#define EFI_RUNTIME_SERVICES_DATA	 6
+#define EFI_CONVENTIONAL_MEMORY		 7
+#define EFI_UNUSABLE_MEMORY		 8
+#define EFI_ACPI_RECLAIM_MEMORY		 9
+#define EFI_ACPI_MEMORY_NVS		10
+#define EFI_MEMORY_MAPPED_IO		11
+#define EFI_MEMORY_MAPPED_IO_PORT_SPACE	12
+#define EFI_PAL_CODE			13
+#define EFI_PERSISTENT_MEMORY		14
+#define EFI_MAX_MEMORY_TYPE		15
+
+/* Attribute values: */
+#define EFI_MEMORY_UC		((u64)0x0000000000000001ULL)	/* uncached */
+#define EFI_MEMORY_WC		((u64)0x0000000000000002ULL)	/* write-coalescing */
+#define EFI_MEMORY_WT		((u64)0x0000000000000004ULL)	/* write-through */
+#define EFI_MEMORY_WB		((u64)0x0000000000000008ULL)	/* write-back */
+#define EFI_MEMORY_UCE		((u64)0x0000000000000010ULL)	/* uncached, exported */
+#define EFI_MEMORY_WP		((u64)0x0000000000001000ULL)	/* write-protect */
+#define EFI_MEMORY_RP		((u64)0x0000000000002000ULL)	/* read-protect */
+#define EFI_MEMORY_XP		((u64)0x0000000000004000ULL)	/* execute-protect */
+#define EFI_MEMORY_NV		((u64)0x0000000000008000ULL)	/* non-volatile */
+#define EFI_MEMORY_MORE_RELIABLE \
+				((u64)0x0000000000010000ULL)	/* higher reliability */
+#define EFI_MEMORY_RO		((u64)0x0000000000020000ULL)	/* read-only */
+#define EFI_MEMORY_SP		((u64)0x0000000000040000ULL)	/* soft reserved */
+#define EFI_MEMORY_CPU_CRYPTO	((u64)0x0000000000080000ULL)	/* supports encryption */
+#define EFI_MEMORY_RUNTIME	((u64)0x8000000000000000ULL)	/* range requires runtime mapping */
+#define EFI_MEMORY_DESCRIPTOR_VERSION	1
+
+#define EFI_PAGE_SHIFT		12
+#define EFI_PAGE_SIZE		(1UL << EFI_PAGE_SHIFT)
+#define EFI_PAGES_MAX		(U64_MAX >> EFI_PAGE_SHIFT)
+
+typedef struct {
+	u32 type;
+	u32 pad;
+	u64 phys_addr;
+	u64 virt_addr;
+	u64 num_pages;
+	u64 attribute;
+} efi_memory_desc_t;
+
+typedef struct {
+	efi_guid_t guid;
+	u32 headersize;
+	u32 flags;
+	u32 imagesize;
+} efi_capsule_header_t;
+
+/*
+ * EFI capsule flags
+ */
+#define EFI_CAPSULE_PERSIST_ACROSS_RESET	0x00010000
+#define EFI_CAPSULE_POPULATE_SYSTEM_TABLE	0x00020000
+#define EFI_CAPSULE_INITIATE_RESET		0x00040000
+
+struct capsule_info {
+	efi_capsule_header_t	header;
+	efi_capsule_header_t	*capsule;
+	int			reset_type;
+	long			index;
+	size_t			count;
+	size_t			total_size;
+	struct page		**pages;
+	phys_addr_t		*phys;
+	size_t			page_bytes_remain;
+};
+
+int __efi_capsule_setup_info(struct capsule_info *cap_info);
+
+/*
+ * Types and defines for Time Services
+ */
+#define EFI_TIME_ADJUST_DAYLIGHT 0x1
+#define EFI_TIME_IN_DAYLIGHT     0x2
+#define EFI_UNSPECIFIED_TIMEZONE 0x07ff
+
+typedef struct {
+	u16 year;
+	u8 month;
+	u8 day;
+	u8 hour;
+	u8 minute;
+	u8 second;
+	u8 pad1;
+	u32 nanosecond;
+	s16 timezone;
+	u8 daylight;
+	u8 pad2;
+} efi_time_t;
+
+typedef struct {
+	u32 resolution;
+	u32 accuracy;
+	u8 sets_to_zero;
+} efi_time_cap_t;
+
+typedef void *efi_event_t;
+/* Note that notifications won't work in mixed mode */
+typedef void (__efiapi *efi_event_notify_t)(efi_event_t, void *);
+
+typedef enum {
+	EfiTimerCancel,
+	EfiTimerPeriodic,
+	EfiTimerRelative
+} EFI_TIMER_DELAY;
+
+/*
+ * EFI Device Path information
+ */
+#define EFI_DEV_HW			0x01
+#define  EFI_DEV_PCI				 1
+#define  EFI_DEV_PCCARD				 2
+#define  EFI_DEV_MEM_MAPPED			 3
+#define  EFI_DEV_VENDOR				 4
+#define  EFI_DEV_CONTROLLER			 5
+#define EFI_DEV_ACPI			0x02
+#define   EFI_DEV_BASIC_ACPI			 1
+#define   EFI_DEV_EXPANDED_ACPI			 2
+#define EFI_DEV_MSG			0x03
+#define   EFI_DEV_MSG_ATAPI			 1
+#define   EFI_DEV_MSG_SCSI			 2
+#define   EFI_DEV_MSG_FC			 3
+#define   EFI_DEV_MSG_1394			 4
+#define   EFI_DEV_MSG_USB			 5
+#define   EFI_DEV_MSG_USB_CLASS			15
+#define   EFI_DEV_MSG_I20			 6
+#define   EFI_DEV_MSG_MAC			11
+#define   EFI_DEV_MSG_IPV4			12
+#define   EFI_DEV_MSG_IPV6			13
+#define   EFI_DEV_MSG_INFINIBAND		 9
+#define   EFI_DEV_MSG_UART			14
+#define   EFI_DEV_MSG_VENDOR			10
+#define EFI_DEV_MEDIA			0x04
+#define   EFI_DEV_MEDIA_HARD_DRIVE		 1
+#define   EFI_DEV_MEDIA_CDROM			 2
+#define   EFI_DEV_MEDIA_VENDOR			 3
+#define   EFI_DEV_MEDIA_FILE			 4
+#define   EFI_DEV_MEDIA_PROTOCOL		 5
+#define EFI_DEV_BIOS_BOOT		0x05
+#define EFI_DEV_END_PATH		0x7F
+#define EFI_DEV_END_PATH2		0xFF
+#define   EFI_DEV_END_INSTANCE			0x01
+#define   EFI_DEV_END_ENTIRE			0xFF
+
+struct efi_generic_dev_path {
+	u8				type;
+	u8				sub_type;
+	u16				length;
+} __packed;
+
+typedef struct efi_generic_dev_path efi_device_path_protocol_t;
+
+/*
+ * EFI Boot Services table
+ */
+union efi_boot_services {
+	struct {
+		efi_table_hdr_t hdr;
+		void *raise_tpl;
+		void *restore_tpl;
+		efi_status_t (__efiapi *allocate_pages)(int, int, unsigned long,
+							efi_physical_addr_t *);
+		efi_status_t (__efiapi *free_pages)(efi_physical_addr_t,
+						    unsigned long);
+		efi_status_t (__efiapi *get_memory_map)(unsigned long *, void *,
+							unsigned long *,
+							unsigned long *, u32 *);
+		efi_status_t (__efiapi *allocate_pool)(int, unsigned long,
+						       void **);
+		efi_status_t (__efiapi *free_pool)(void *);
+		efi_status_t (__efiapi *create_event)(u32, unsigned long,
+						      efi_event_notify_t, void *,
+						      efi_event_t *);
+		efi_status_t (__efiapi *set_timer)(efi_event_t,
+						  EFI_TIMER_DELAY, u64);
+		efi_status_t (__efiapi *wait_for_event)(unsigned long,
+							efi_event_t *,
+							unsigned long *);
+		void *signal_event;
+		efi_status_t (__efiapi *close_event)(efi_event_t);
+		void *check_event;
+		void *install_protocol_interface;
+		void *reinstall_protocol_interface;
+		void *uninstall_protocol_interface;
+		efi_status_t (__efiapi *handle_protocol)(efi_handle_t,
+							 efi_guid_t *, void **);
+		void *__reserved;
+		void *register_protocol_notify;
+		efi_status_t (__efiapi *locate_handle)(int, efi_guid_t *,
+						       void *, unsigned long *,
+						       efi_handle_t *);
+		efi_status_t (__efiapi *locate_device_path)(efi_guid_t *,
+							    efi_device_path_protocol_t **,
+							    efi_handle_t *);
+		efi_status_t (__efiapi *install_configuration_table)(efi_guid_t *,
+								     void *);
+		void *load_image;
+		void *start_image;
+		efi_status_t (__efiapi *exit)(efi_handle_t,
+							 efi_status_t,
+							 unsigned long,
+							 efi_char16_t *);
+		void *unload_image;
+		efi_status_t (__efiapi *exit_boot_services)(efi_handle_t,
+							    unsigned long);
+		void *get_next_monotonic_count;
+		efi_status_t (__efiapi *stall)(unsigned long);
+		void *set_watchdog_timer;
+		void *connect_controller;
+		efi_status_t (__efiapi *disconnect_controller)(efi_handle_t,
+							       efi_handle_t,
+							       efi_handle_t);
+		void *open_protocol;
+		void *close_protocol;
+		void *open_protocol_information;
+		void *protocols_per_handle;
+		void *locate_handle_buffer;
+		efi_status_t (__efiapi *locate_protocol)(efi_guid_t *, void *,
+							 void **);
+		void *install_multiple_protocol_interfaces;
+		void *uninstall_multiple_protocol_interfaces;
+		void *calculate_crc32;
+		void *copy_mem;
+		void *set_mem;
+		void *create_event_ex;
+	};
+	struct {
+		efi_table_hdr_t hdr;
+		u32 raise_tpl;
+		u32 restore_tpl;
+		u32 allocate_pages;
+		u32 free_pages;
+		u32 get_memory_map;
+		u32 allocate_pool;
+		u32 free_pool;
+		u32 create_event;
+		u32 set_timer;
+		u32 wait_for_event;
+		u32 signal_event;
+		u32 close_event;
+		u32 check_event;
+		u32 install_protocol_interface;
+		u32 reinstall_protocol_interface;
+		u32 uninstall_protocol_interface;
+		u32 handle_protocol;
+		u32 __reserved;
+		u32 register_protocol_notify;
+		u32 locate_handle;
+		u32 locate_device_path;
+		u32 install_configuration_table;
+		u32 load_image;
+		u32 start_image;
+		u32 exit;
+		u32 unload_image;
+		u32 exit_boot_services;
+		u32 get_next_monotonic_count;
+		u32 stall;
+		u32 set_watchdog_timer;
+		u32 connect_controller;
+		u32 disconnect_controller;
+		u32 open_protocol;
+		u32 close_protocol;
+		u32 open_protocol_information;
+		u32 protocols_per_handle;
+		u32 locate_handle_buffer;
+		u32 locate_protocol;
+		u32 install_multiple_protocol_interfaces;
+		u32 uninstall_multiple_protocol_interfaces;
+		u32 calculate_crc32;
+		u32 copy_mem;
+		u32 set_mem;
+		u32 create_event_ex;
+	} mixed_mode;
+};
+
+typedef union efi_boot_services efi_boot_services_t;
+
+/*
+ * Types and defines for EFI ResetSystem
+ */
+#define EFI_RESET_COLD 0
+#define EFI_RESET_WARM 1
+#define EFI_RESET_SHUTDOWN 2
+
+/*
+ * EFI Runtime Services table
+ */
+#define EFI_RUNTIME_SERVICES_SIGNATURE ((u64)0x5652453544e5552ULL)
+#define EFI_RUNTIME_SERVICES_REVISION  0x00010000
+
+typedef struct {
+	efi_table_hdr_t hdr;
+	u32 get_time;
+	u32 set_time;
+	u32 get_wakeup_time;
+	u32 set_wakeup_time;
+	u32 set_virtual_address_map;
+	u32 convert_pointer;
+	u32 get_variable;
+	u32 get_next_variable;
+	u32 set_variable;
+	u32 get_next_high_mono_count;
+	u32 reset_system;
+	u32 update_capsule;
+	u32 query_capsule_caps;
+	u32 query_variable_info;
+} efi_runtime_services_32_t;
+
+typedef efi_status_t efi_get_time_t (efi_time_t *tm, efi_time_cap_t *tc);
+typedef efi_status_t efi_set_time_t (efi_time_t *tm);
+typedef efi_status_t efi_get_wakeup_time_t (efi_bool_t *enabled, efi_bool_t *pending,
+					    efi_time_t *tm);
+typedef efi_status_t efi_set_wakeup_time_t (efi_bool_t enabled, efi_time_t *tm);
+typedef efi_status_t efi_get_variable_t (efi_char16_t *name, efi_guid_t *vendor, u32 *attr,
+					 unsigned long *data_size, void *data);
+typedef efi_status_t efi_get_next_variable_t (unsigned long *name_size, efi_char16_t *name,
+					      efi_guid_t *vendor);
+typedef efi_status_t efi_set_variable_t (efi_char16_t *name, efi_guid_t *vendor,
+					 u32 attr, unsigned long data_size,
+					 void *data);
+typedef efi_status_t efi_get_next_high_mono_count_t (u32 *count);
+typedef void efi_reset_system_t (int reset_type, efi_status_t status,
+				 unsigned long data_size, efi_char16_t *data);
+typedef efi_status_t efi_set_virtual_address_map_t (unsigned long memory_map_size,
+						unsigned long descriptor_size,
+						u32 descriptor_version,
+						efi_memory_desc_t *virtual_map);
+typedef efi_status_t efi_query_variable_info_t(u32 attr,
+					       u64 *storage_space,
+					       u64 *remaining_space,
+					       u64 *max_variable_size);
+typedef efi_status_t efi_update_capsule_t(efi_capsule_header_t **capsules,
+					  unsigned long count,
+					  unsigned long sg_list);
+typedef efi_status_t efi_query_capsule_caps_t(efi_capsule_header_t **capsules,
+					      unsigned long count,
+					      u64 *max_size,
+					      int *reset_type);
+typedef efi_status_t efi_query_variable_store_t(u32 attributes,
+						unsigned long size,
+						bool nonblocking);
+
+typedef union {
+	struct {
+		efi_table_hdr_t				hdr;
+		efi_get_time_t __efiapi			*get_time;
+		efi_set_time_t __efiapi			*set_time;
+		efi_get_wakeup_time_t __efiapi		*get_wakeup_time;
+		efi_set_wakeup_time_t __efiapi		*set_wakeup_time;
+		efi_set_virtual_address_map_t __efiapi	*set_virtual_address_map;
+		void					*convert_pointer;
+		efi_get_variable_t __efiapi		*get_variable;
+		efi_get_next_variable_t __efiapi	*get_next_variable;
+		efi_set_variable_t __efiapi		*set_variable;
+		efi_get_next_high_mono_count_t __efiapi	*get_next_high_mono_count;
+		efi_reset_system_t __efiapi		*reset_system;
+		efi_update_capsule_t __efiapi		*update_capsule;
+		efi_query_capsule_caps_t __efiapi	*query_capsule_caps;
+		efi_query_variable_info_t __efiapi	*query_variable_info;
+	};
+	efi_runtime_services_32_t mixed_mode;
+} efi_runtime_services_t;
+
+#define EFI_SYSTEM_TABLE_SIGNATURE ((u64)0x5453595320494249ULL)
+
+#define EFI_2_30_SYSTEM_TABLE_REVISION  ((2 << 16) | (30))
+#define EFI_2_20_SYSTEM_TABLE_REVISION  ((2 << 16) | (20))
+#define EFI_2_10_SYSTEM_TABLE_REVISION  ((2 << 16) | (10))
+#define EFI_2_00_SYSTEM_TABLE_REVISION  ((2 << 16) | (00))
+#define EFI_1_10_SYSTEM_TABLE_REVISION  ((1 << 16) | (10))
+#define EFI_1_02_SYSTEM_TABLE_REVISION  ((1 << 16) | (02))
+
+typedef struct {
+	efi_table_hdr_t hdr;
+	u64 fw_vendor;	/* physical addr of CHAR16 vendor string */
+	u32 fw_revision;
+	u32 __pad1;
+	u64 con_in_handle;
+	u64 con_in;
+	u64 con_out_handle;
+	u64 con_out;
+	u64 stderr_handle;
+	u64 stderr;
+	u64 runtime;
+	u64 boottime;
+	u32 nr_tables;
+	u32 __pad2;
+	u64 tables;
+} efi_system_table_64_t;
+
+typedef struct {
+	efi_table_hdr_t hdr;
+	u32 fw_vendor;	/* physical addr of CHAR16 vendor string */
+	u32 fw_revision;
+	u32 con_in_handle;
+	u32 con_in;
+	u32 con_out_handle;
+	u32 con_out;
+	u32 stderr_handle;
+	u32 stderr;
+	u32 runtime;
+	u32 boottime;
+	u32 nr_tables;
+	u32 tables;
+} efi_system_table_32_t;
+
+typedef union efi_simple_text_input_protocol efi_simple_text_input_protocol_t;
+typedef union efi_simple_text_output_protocol efi_simple_text_output_protocol_t;
+
+typedef union {
+	struct {
+		efi_table_hdr_t hdr;
+		unsigned long fw_vendor;	/* physical addr of CHAR16 vendor string */
+		u32 fw_revision;
+		unsigned long con_in_handle;
+		efi_simple_text_input_protocol_t *con_in;
+		unsigned long con_out_handle;
+		efi_simple_text_output_protocol_t *con_out;
+		unsigned long stderr_handle;
+		unsigned long stderr;
+		efi_runtime_services_t *runtime;
+		efi_boot_services_t *boottime;
+		unsigned long nr_tables;
+		unsigned long tables;
+	};
+	efi_system_table_32_t mixed_mode;
+} efi_system_table_t;
+
+struct efi_boot_memmap {
+	efi_memory_desc_t       **map;
+	unsigned long           *map_size;
+	unsigned long           *desc_size;
+	u32                     *desc_ver;
+	unsigned long           *key_ptr;
+	unsigned long           *buff_size;
+};
+
+#define efi_bs_call(func, ...)						\
+	efi_system_table->boottime->func(__VA_ARGS__)
+
+#endif /* __LINUX_UEFI_H */
