Merge remote-tracking branch 'tip/x86/efi-mixed' into efi-for-mingo

Conflicts:
	arch/x86/kernel/setup.c
	arch/x86/platform/efi/efi.c
	arch/x86/platform/efi/efi_64.c
This commit is contained in:
Matt Fleming
2014-03-05 18:15:37 +00:00
20 changed files with 2130 additions and 451 deletions

View File

@@ -1,3 +1,4 @@
obj-$(CONFIG_EFI) += efi.o efi_$(BITS).o efi_stub_$(BITS).o
obj-$(CONFIG_ACPI_BGRT) += efi-bgrt.o
obj-$(CONFIG_EARLY_PRINTK_EFI) += early_printk.o
obj-$(CONFIG_EFI_MIXED) += efi_thunk_$(BITS).o

View File

@@ -453,9 +453,6 @@ void __init efi_free_boot_services(void)
{
void *p;
if (!efi_is_native())
return;
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
efi_memory_desc_t *md = p;
unsigned long long start = md->phys_addr;
@@ -579,9 +576,71 @@ static int __init efi_systab_init(void *phys)
return 0;
}
static int __init efi_runtime_init32(void)
{
efi_runtime_services_32_t *runtime;
runtime = early_ioremap((unsigned long)efi.systab->runtime,
sizeof(efi_runtime_services_32_t));
if (!runtime) {
pr_err("Could not map the runtime service table!\n");
return -ENOMEM;
}
/*
* We will only need *early* access to the following two
* EFI runtime services before set_virtual_address_map
* is invoked.
*/
efi_phys.get_time = (efi_get_time_t *)
(unsigned long)runtime->get_time;
efi_phys.set_virtual_address_map =
(efi_set_virtual_address_map_t *)
(unsigned long)runtime->set_virtual_address_map;
/*
* Make efi_get_time can be called before entering
* virtual mode.
*/
efi.get_time = phys_efi_get_time;
early_iounmap(runtime, sizeof(efi_runtime_services_32_t));
return 0;
}
static int __init efi_runtime_init64(void)
{
efi_runtime_services_64_t *runtime;
runtime = early_ioremap((unsigned long)efi.systab->runtime,
sizeof(efi_runtime_services_64_t));
if (!runtime) {
pr_err("Could not map the runtime service table!\n");
return -ENOMEM;
}
/*
* We will only need *early* access to the following two
* EFI runtime services before set_virtual_address_map
* is invoked.
*/
efi_phys.get_time = (efi_get_time_t *)
(unsigned long)runtime->get_time;
efi_phys.set_virtual_address_map =
(efi_set_virtual_address_map_t *)
(unsigned long)runtime->set_virtual_address_map;
/*
* Make efi_get_time can be called before entering
* virtual mode.
*/
efi.get_time = phys_efi_get_time;
early_iounmap(runtime, sizeof(efi_runtime_services_64_t));
return 0;
}
static int __init efi_runtime_init(void)
{
efi_runtime_services_t *runtime;
int rv;
/*
* Check out the runtime services table. We need to map
@@ -589,27 +648,13 @@ static int __init efi_runtime_init(void)
* address of several of the EFI runtime functions, needed to
* set the firmware into virtual mode.
*/
runtime = early_ioremap((unsigned long)efi.systab->runtime,
sizeof(efi_runtime_services_t));
if (!runtime) {
pr_err("Could not map the runtime service table!\n");
return -ENOMEM;
}
/*
* We will only need *early* access to the following
* two EFI runtime services before set_virtual_address_map
* is invoked.
*/
efi_phys.get_time = (efi_get_time_t *)runtime->get_time;
efi_phys.set_virtual_address_map =
(efi_set_virtual_address_map_t *)
runtime->set_virtual_address_map;
/*
* Make efi_get_time can be called before entering
* virtual mode.
*/
efi.get_time = phys_efi_get_time;
early_iounmap(runtime, sizeof(efi_runtime_services_t));
if (efi_enabled(EFI_64BIT))
rv = efi_runtime_init64();
else
rv = efi_runtime_init32();
if (rv)
return rv;
set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
@@ -747,7 +792,7 @@ void __init efi_init(void)
* that doesn't match the kernel 32/64-bit mode.
*/
if (!efi_is_native())
if (!efi_runtime_supported())
pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
else {
if (disable_runtime || efi_runtime_init())
@@ -833,6 +878,22 @@ void __init old_map_region(efi_memory_desc_t *md)
(unsigned long long)md->phys_addr);
}
static void native_runtime_setup(void)
{
efi.get_time = virt_efi_get_time;
efi.set_time = virt_efi_set_time;
efi.get_wakeup_time = virt_efi_get_wakeup_time;
efi.set_wakeup_time = virt_efi_set_wakeup_time;
efi.get_variable = virt_efi_get_variable;
efi.get_next_variable = virt_efi_get_next_variable;
efi.set_variable = virt_efi_set_variable;
efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
efi.reset_system = virt_efi_reset_system;
efi.query_variable_info = virt_efi_query_variable_info;
efi.update_capsule = virt_efi_update_capsule;
efi.query_capsule_caps = virt_efi_query_capsule_caps;
}
/* Merge contiguous regions of the same type and attribute */
static void __init efi_merge_regions(void)
{
@@ -1015,19 +1076,10 @@ static void __init kexec_enter_virtual_mode(void)
* Call EFI services through wrapper functions.
*/
efi.runtime_version = efi_systab.hdr.revision;
efi.get_time = virt_efi_get_time;
efi.set_time = virt_efi_set_time;
efi.get_wakeup_time = virt_efi_get_wakeup_time;
efi.set_wakeup_time = virt_efi_set_wakeup_time;
efi.get_variable = virt_efi_get_variable;
efi.get_next_variable = virt_efi_get_next_variable;
efi.set_variable = virt_efi_set_variable;
efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
efi.reset_system = virt_efi_reset_system;
native_runtime_setup();
efi.set_virtual_address_map = NULL;
efi.query_variable_info = virt_efi_query_variable_info;
efi.update_capsule = virt_efi_update_capsule;
efi.query_capsule_caps = virt_efi_query_capsule_caps;
if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
runtime_code_page_mkexec();
@@ -1071,15 +1123,6 @@ static void __init __efi_enter_virtual_mode(void)
efi.systab = NULL;
/*
* We don't do virtual mode, since we don't do runtime services, on
* non-native EFI
*/
if (!efi_is_native()) {
efi_unmap_memmap();
return;
}
efi_merge_regions();
new_memmap = efi_map_regions(&count, &pg_shift);
if (!new_memmap) {
@@ -1097,11 +1140,20 @@ static void __init __efi_enter_virtual_mode(void)
efi_sync_low_kernel_mappings();
efi_dump_pagetable();
status = phys_efi_set_virtual_address_map(
memmap.desc_size * count,
memmap.desc_size,
memmap.desc_version,
(efi_memory_desc_t *)__pa(new_memmap));
if (efi_is_native()) {
status = phys_efi_set_virtual_address_map(
memmap.desc_size * count,
memmap.desc_size,
memmap.desc_version,
(efi_memory_desc_t *)__pa(new_memmap));
} else {
status = efi_thunk_set_virtual_address_map(
efi_phys.set_virtual_address_map,
memmap.desc_size * count,
memmap.desc_size,
memmap.desc_version,
(efi_memory_desc_t *)__pa(new_memmap));
}
if (status != EFI_SUCCESS) {
pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
@@ -1116,19 +1168,13 @@ static void __init __efi_enter_virtual_mode(void)
* Call EFI services through wrapper functions.
*/
efi.runtime_version = efi_systab.hdr.revision;
efi.get_time = virt_efi_get_time;
efi.set_time = virt_efi_set_time;
efi.get_wakeup_time = virt_efi_get_wakeup_time;
efi.set_wakeup_time = virt_efi_set_wakeup_time;
efi.get_variable = virt_efi_get_variable;
efi.get_next_variable = virt_efi_get_next_variable;
efi.set_variable = virt_efi_set_variable;
efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
efi.reset_system = virt_efi_reset_system;
if (efi_is_native())
native_runtime_setup();
else
efi_thunk_runtime_setup();
efi.set_virtual_address_map = NULL;
efi.query_variable_info = virt_efi_query_variable_info;
efi.update_capsule = virt_efi_update_capsule;
efi.query_capsule_caps = virt_efi_query_capsule_caps;
efi_runtime_mkexec();
@@ -1311,7 +1357,7 @@ void __init efi_apply_memmap_quirks(void)
* firmware/kernel architectures since there is no support for runtime
* services.
*/
if (!efi_is_native()) {
if (!efi_runtime_supported()) {
pr_info("efi: Setup done, disabling due to 32/64-bit mismatch\n");
efi_unmap_memmap();
}

View File

@@ -39,6 +39,7 @@
#include <asm/cacheflush.h>
#include <asm/fixmap.h>
#include <asm/realmode.h>
#include <asm/time.h>
static pgd_t *save_pgd __initdata;
static unsigned long efi_flags __initdata;
@@ -58,7 +59,8 @@ struct efi_scratch {
u64 prev_cr3;
pgd_t *efi_pgt;
bool use_pgd;
};
u64 phys_stack;
} __packed;
static void __init early_code_mapping_set_exec(int executable)
{
@@ -139,6 +141,9 @@ void efi_sync_low_kernel_mappings(void)
int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
{
unsigned long text;
struct page *page;
unsigned npages;
pgd_t *pgd;
if (efi_enabled(EFI_OLD_MEMMAP))
@@ -160,6 +165,29 @@ int efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
efi_scratch.use_pgd = true;
/*
* When making calls to the firmware everything needs to be 1:1
* mapped and addressable with 32-bit pointers. Map the kernel
* text and allocate a new stack because we can't rely on the
* stack pointer being < 4GB.
*/
if (!IS_ENABLED(CONFIG_EFI_MIXED))
return 0;
page = alloc_page(GFP_KERNEL|__GFP_DMA32);
if (!page)
panic("Unable to allocate EFI runtime stack < 4GB\n");
efi_scratch.phys_stack = virt_to_phys(page_address(page));
efi_scratch.phys_stack += PAGE_SIZE; /* stack grows down */
npages = (_end - _text) >> PAGE_SHIFT;
text = __pa(_text);
if (kernel_map_pages_in_pgd(pgd, text >> PAGE_SHIFT, text, npages, 0)) {
pr_err("Failed to map kernel text 1:1\n");
return 1;
}
return 0;
}
@@ -199,6 +227,16 @@ void __init efi_map_region(efi_memory_desc_t *md)
*/
__map_region(md, md->phys_addr);
/*
* Enforce the 1:1 mapping as the default virtual address when
* booting in EFI mixed mode, because even though we may be
* running a 64-bit kernel, the firmware may only be 32-bit.
*/
if (!efi_is_native () && IS_ENABLED(CONFIG_EFI_MIXED)) {
md->virt_addr = md->phys_addr;
return;
}
efi_va -= size;
/* Is PA 2M-aligned? */
@@ -277,3 +315,290 @@ void __init efi_dump_pagetable(void)
ptdump_walk_pgd_level(NULL, pgd);
#endif
}
#ifdef CONFIG_EFI_MIXED
extern efi_status_t efi64_thunk(u32, ...);
#define runtime_service32(func) \
({ \
u32 table = (u32)(unsigned long)efi.systab; \
u32 *rt, *___f; \
\
rt = (u32 *)(table + offsetof(efi_system_table_32_t, runtime)); \
___f = (u32 *)(*rt + offsetof(efi_runtime_services_32_t, func)); \
*___f; \
})
/*
* Switch to the EFI page tables early so that we can access the 1:1
* runtime services mappings which are not mapped in any other page
* tables. This function must be called before runtime_service32().
*
* Also, disable interrupts because the IDT points to 64-bit handlers,
* which aren't going to function correctly when we switch to 32-bit.
*/
#define efi_thunk(f, ...) \
({ \
efi_status_t __s; \
unsigned long flags; \
u32 func; \
\
efi_sync_low_kernel_mappings(); \
local_irq_save(flags); \
\
efi_scratch.prev_cr3 = read_cr3(); \
write_cr3((unsigned long)efi_scratch.efi_pgt); \
__flush_tlb_all(); \
\
func = runtime_service32(f); \
__s = efi64_thunk(func, __VA_ARGS__); \
\
write_cr3(efi_scratch.prev_cr3); \
__flush_tlb_all(); \
local_irq_restore(flags); \
\
__s; \
})
efi_status_t efi_thunk_set_virtual_address_map(
void *phys_set_virtual_address_map,
unsigned long memory_map_size,
unsigned long descriptor_size,
u32 descriptor_version,
efi_memory_desc_t *virtual_map)
{
efi_status_t status;
unsigned long flags;
u32 func;
efi_sync_low_kernel_mappings();
local_irq_save(flags);
efi_scratch.prev_cr3 = read_cr3();
write_cr3((unsigned long)efi_scratch.efi_pgt);
__flush_tlb_all();
func = (u32)(unsigned long)phys_set_virtual_address_map;
status = efi64_thunk(func, memory_map_size, descriptor_size,
descriptor_version, virtual_map);
write_cr3(efi_scratch.prev_cr3);
__flush_tlb_all();
local_irq_restore(flags);
return status;
}
static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc)
{
efi_status_t status;
u32 phys_tm, phys_tc;
spin_lock(&rtc_lock);
phys_tm = virt_to_phys(tm);
phys_tc = virt_to_phys(tc);
status = efi_thunk(get_time, phys_tm, phys_tc);
spin_unlock(&rtc_lock);
return status;
}
static efi_status_t efi_thunk_set_time(efi_time_t *tm)
{
efi_status_t status;
u32 phys_tm;
spin_lock(&rtc_lock);
phys_tm = virt_to_phys(tm);
status = efi_thunk(set_time, phys_tm);
spin_unlock(&rtc_lock);
return status;
}
static efi_status_t
efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending,
efi_time_t *tm)
{
efi_status_t status;
u32 phys_enabled, phys_pending, phys_tm;
spin_lock(&rtc_lock);
phys_enabled = virt_to_phys(enabled);
phys_pending = virt_to_phys(pending);
phys_tm = virt_to_phys(tm);
status = efi_thunk(get_wakeup_time, phys_enabled,
phys_pending, phys_tm);
spin_unlock(&rtc_lock);
return status;
}
static efi_status_t
efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
{
efi_status_t status;
u32 phys_tm;
spin_lock(&rtc_lock);
phys_tm = virt_to_phys(tm);
status = efi_thunk(set_wakeup_time, enabled, phys_tm);
spin_unlock(&rtc_lock);
return status;
}
static efi_status_t
efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor,
u32 *attr, unsigned long *data_size, void *data)
{
efi_status_t status;
u32 phys_name, phys_vendor, phys_attr;
u32 phys_data_size, phys_data;
phys_data_size = virt_to_phys(data_size);
phys_vendor = virt_to_phys(vendor);
phys_name = virt_to_phys(name);
phys_attr = virt_to_phys(attr);
phys_data = virt_to_phys(data);
status = efi_thunk(get_variable, phys_name, phys_vendor,
phys_attr, phys_data_size, phys_data);
return status;
}
static efi_status_t
efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor,
u32 attr, unsigned long data_size, void *data)
{
u32 phys_name, phys_vendor, phys_data;
efi_status_t status;
phys_name = virt_to_phys(name);
phys_vendor = virt_to_phys(vendor);
phys_data = virt_to_phys(data);
/* If data_size is > sizeof(u32) we've got problems */
status = efi_thunk(set_variable, phys_name, phys_vendor,
attr, data_size, phys_data);
return status;
}
static efi_status_t
efi_thunk_get_next_variable(unsigned long *name_size,
efi_char16_t *name,
efi_guid_t *vendor)
{
efi_status_t status;
u32 phys_name_size, phys_name, phys_vendor;
phys_name_size = virt_to_phys(name_size);
phys_vendor = virt_to_phys(vendor);
phys_name = virt_to_phys(name);
status = efi_thunk(get_next_variable, phys_name_size,
phys_name, phys_vendor);
return status;
}
static efi_status_t
efi_thunk_get_next_high_mono_count(u32 *count)
{
efi_status_t status;
u32 phys_count;
phys_count = virt_to_phys(count);
status = efi_thunk(get_next_high_mono_count, phys_count);
return status;
}
static void
efi_thunk_reset_system(int reset_type, efi_status_t status,
unsigned long data_size, efi_char16_t *data)
{
u32 phys_data;
phys_data = virt_to_phys(data);
efi_thunk(reset_system, reset_type, status, data_size, phys_data);
}
static efi_status_t
efi_thunk_update_capsule(efi_capsule_header_t **capsules,
unsigned long count, unsigned long sg_list)
{
/*
* To properly support this function we would need to repackage
* 'capsules' because the firmware doesn't understand 64-bit
* pointers.
*/
return EFI_UNSUPPORTED;
}
static efi_status_t
efi_thunk_query_variable_info(u32 attr, u64 *storage_space,
u64 *remaining_space,
u64 *max_variable_size)
{
efi_status_t status;
u32 phys_storage, phys_remaining, phys_max;
if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
return EFI_UNSUPPORTED;
phys_storage = virt_to_phys(storage_space);
phys_remaining = virt_to_phys(remaining_space);
phys_max = virt_to_phys(max_variable_size);
status = efi_thunk(query_variable_info, phys_storage,
phys_remaining, phys_max);
return status;
}
static efi_status_t
efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules,
unsigned long count, u64 *max_size,
int *reset_type)
{
/*
* To properly support this function we would need to repackage
* 'capsules' because the firmware doesn't understand 64-bit
* pointers.
*/
return EFI_UNSUPPORTED;
}
void efi_thunk_runtime_setup(void)
{
efi.get_time = efi_thunk_get_time;
efi.set_time = efi_thunk_set_time;
efi.get_wakeup_time = efi_thunk_get_wakeup_time;
efi.set_wakeup_time = efi_thunk_set_wakeup_time;
efi.get_variable = efi_thunk_get_variable;
efi.get_next_variable = efi_thunk_get_next_variable;
efi.set_variable = efi_thunk_set_variable;
efi.get_next_high_mono_count = efi_thunk_get_next_high_mono_count;
efi.reset_system = efi_thunk_reset_system;
efi.query_variable_info = efi_thunk_query_variable_info;
efi.update_capsule = efi_thunk_update_capsule;
efi.query_capsule_caps = efi_thunk_query_capsule_caps;
}
#endif /* CONFIG_EFI_MIXED */

View File

@@ -7,6 +7,10 @@
*/
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/msr.h>
#include <asm/processor-flags.h>
#include <asm/page_types.h>
#define SAVE_XMM \
mov %rsp, %rax; \
@@ -164,7 +168,160 @@ ENTRY(efi_call6)
ret
ENDPROC(efi_call6)
#ifdef CONFIG_EFI_MIXED
/*
* We run this function from the 1:1 mapping.
*
* This function must be invoked with a 1:1 mapped stack.
*/
ENTRY(__efi64_thunk)
subq $32, %rsp
movl %esi, 0x0(%rsp)
movl %edx, 0x4(%rsp)
movl %ecx, 0x8(%rsp)
movq %r8, %rsi
movl %esi, 0xc(%rsp)
movq %r9, %rsi
movl %esi, 0x10(%rsp)
sgdt save_gdt(%rip)
leaq 1f(%rip), %rbx
movq %rbx, func_rt_ptr(%rip)
/* Switch to gdt with 32-bit segments */
movl 40(%rsp), %eax
lgdt (%rax)
leaq efi_enter32(%rip), %rax
pushq $__KERNEL_CS
pushq %rax
lretq
1: addq $32, %rsp
lgdt save_gdt(%rip)
/*
* Convert 32-bit status code into 64-bit.
*/
test %rax, %rax
jz 1f
movl %eax, %ecx
andl $0x0fffffff, %ecx
andl $0xf0000000, %eax
shl $32, %rax
or %rcx, %rax
1:
ret
ENDPROC(__efi64_thunk)
ENTRY(efi_exit32)
xorq %rax, %rax
movl %eax, %ds
movl %eax, %es
movl %eax, %ss
movq func_rt_ptr(%rip), %rax
push %rax
mov %rdi, %rax
ret
ENDPROC(efi_exit32)
.code32
/*
* EFI service pointer must be in %edi.
*
* The stack should represent the 32-bit calling convention.
*/
ENTRY(efi_enter32)
movl $__KERNEL_DS, %eax
movl %eax, %ds
movl %eax, %es
movl %eax, %ss
/* Reload pgtables */
movl %cr3, %eax
movl %eax, %cr3
/* Disable paging */
movl %cr0, %eax
btrl $X86_CR0_PG_BIT, %eax
movl %eax, %cr0
/* Disable long mode via EFER */
movl $MSR_EFER, %ecx
rdmsr
btrl $_EFER_LME, %eax
wrmsr
call *%edi
/* We must preserve return value */
movl %eax, %edi
/*
* Some firmware will return with interrupts enabled. Be sure to
* disable them before we switch GDTs.
*/
cli
movl 44(%esp), %eax
movl %eax, 2(%eax)
lgdtl (%eax)
movl %cr4, %eax
btsl $(X86_CR4_PAE_BIT), %eax
movl %eax, %cr4
movl %cr3, %eax
movl %eax, %cr3
movl $MSR_EFER, %ecx
rdmsr
btsl $_EFER_LME, %eax
wrmsr
xorl %eax, %eax
lldt %ax
movl 48(%esp), %eax
pushl $__KERNEL_CS
pushl %eax
/* Enable paging */
movl %cr0, %eax
btsl $X86_CR0_PG_BIT, %eax
movl %eax, %cr0
lret
ENDPROC(efi_enter32)
.data
.balign 8
.global efi32_boot_gdt
efi32_boot_gdt: .word 0
.quad 0
save_gdt: .word 0
.quad 0
func_rt_ptr: .quad 0
.global efi_gdt64
efi_gdt64:
.word efi_gdt64_end - efi_gdt64
.long 0 /* Filled out by user */
.word 0
.quad 0x0000000000000000 /* NULL descriptor */
.quad 0x00af9a000000ffff /* __KERNEL_CS */
.quad 0x00cf92000000ffff /* __KERNEL_DS */
.quad 0x0080890000000000 /* TS descriptor */
.quad 0x0000000000000000 /* TS continued */
efi_gdt64_end:
#endif /* CONFIG_EFI_MIXED */
.data
ENTRY(efi_scratch)
.fill 3,8,0
.byte 0
.quad 0

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@@ -0,0 +1,65 @@
/*
* Copyright (C) 2014 Intel Corporation; author Matt Fleming
*/
#include <linux/linkage.h>
#include <asm/page_types.h>
.text
.code64
ENTRY(efi64_thunk)
push %rbp
push %rbx
/*
* Switch to 1:1 mapped 32-bit stack pointer.
*/
movq %rsp, efi_saved_sp(%rip)
movq efi_scratch+25(%rip), %rsp
/*
* Calculate the physical address of the kernel text.
*/
movq $__START_KERNEL_map, %rax
subq phys_base(%rip), %rax
/*
* Push some physical addresses onto the stack. This is easier
* to do now in a code64 section while the assembler can address
* 64-bit values. Note that all the addresses on the stack are
* 32-bit.
*/
subq $16, %rsp
leaq efi_exit32(%rip), %rbx
subq %rax, %rbx
movl %ebx, 8(%rsp)
leaq efi_gdt64(%rip), %rbx
subq %rax, %rbx
movl %ebx, 2(%ebx)
movl %ebx, 4(%rsp)
leaq efi_gdt32(%rip), %rbx
subq %rax, %rbx
movl %ebx, 2(%ebx)
movl %ebx, (%rsp)
leaq __efi64_thunk(%rip), %rbx
subq %rax, %rbx
call *%rbx
movq efi_saved_sp(%rip), %rsp
pop %rbx
pop %rbp
retq
ENDPROC(efi64_thunk)
.data
efi_gdt32:
.word efi_gdt32_end - efi_gdt32
.long 0 /* Filled out above */
.word 0
.quad 0x0000000000000000 /* NULL descriptor */
.quad 0x00cf9a000000ffff /* __KERNEL_CS */
.quad 0x00cf93000000ffff /* __KERNEL_DS */
efi_gdt32_end:
efi_saved_sp: .quad 0