On 8/19/21 4:33 AM, Varad Gautam wrote:
EFI calls _efi_pe_entry in long mode with the location of EFI
handle/system table. Add an efi_main() C handler to make it easier
to communicate with EFI for initial setup. efi_main will later,
1. Acquire the efi memmap
2. Call ExitBootServices
3. Perform remaining bootstrapping before calling the testcase main()
Signed-off-by: Varad Gautam<varad.gautam@xxxxxxxx>
---
lib/linux/uefi.h | 518 ++++++++++++++++++++++++++++++++++++++++++++
x86/Makefile.common | 2 +-
x86/cstart64.S | 10 +-
x86/efi_main.c | 11 +
4 files changed, 539 insertions(+), 2 deletions(-)
create mode 100644 lib/linux/uefi.h
create mode 100644 x86/efi_main.c
diff --git a/lib/linux/uefi.h b/lib/linux/uefi.h
new file mode 100644
index 0000000..15692eb
--- /dev/null
+++ b/lib/linux/uefi.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;
+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;
BTW, the following syntax is also allowed by gcc and you can use it here:
+typedef struct efi_generic_dev_path {
+ u8 type;
+ u8 sub_type;
+ u16 length;
+} __packed, 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;
It's probably better to group the function pointers together for
readability purposes.
+ };
+ 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;
Just curious why we need mixed mode because we are building the tests as
64-bit UEFI executable.
+};
+
+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 */
diff --git a/x86/Makefile.common b/x86/Makefile.common
index fc9a693..ca33e8e 100644
--- a/x86/Makefile.common
+++ b/x86/Makefile.common
@@ -50,7 +50,7 @@ FLATLIBS = lib/libcflat.a
$(OBJCOPY) -O elf32-i386 $^ $@
@chmod a-x $@
-%.so: %.o $(FLATLIBS) $(cstart.o)
+%.so: %.o $(FLATLIBS) $(TEST_DIR)/efi_main.o $(cstart.o)
$(LD) -shared -nostdlib -znocombreloc -Bsymbolic -T $(SRCDIR)/x86/efi.lds $^ \
-o $@ $(FLATLIBS)
@chmod a-x $@
diff --git a/x86/cstart64.S b/x86/cstart64.S
index 404fcac..98e7848 100644
--- a/x86/cstart64.S
+++ b/x86/cstart64.S
@@ -267,7 +267,15 @@ ap_start64:
#ifdef CONFIG_EFI
.globl _efi_pe_entry
_efi_pe_entry:
- ret
+ # EFI image loader calls this with rcx=efi_handle,
+ # rdx=efi_system_table. Pass these to efi_main.
+ mov %rcx, %rdi
+ mov %rdx, %rsi
+
+ pushq %rdi
+ pushq %rsi
+
+ call efi_main
#endif
start64:
diff --git a/x86/efi_main.c b/x86/efi_main.c
new file mode 100644
index 0000000..00e7086
--- /dev/null
+++ b/x86/efi_main.c
@@ -0,0 +1,11 @@
+#include <linux/uefi.h>
+
+unsigned long __efiapi efi_main(efi_handle_t handle, efi_system_table_t *sys_tab);
+efi_system_table_t *efi_system_table = NULL;
+
+unsigned long __efiapi efi_main(efi_handle_t handle, efi_system_table_t *sys_tab)
+{
+ efi_system_table = sys_tab;
+
+ return 0;
+}
