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-rw-r--r--arch/arm64/kernel/efi-header.S43
-rw-r--r--arch/arm64/kernel/head.S19
2 files changed, 35 insertions, 27 deletions
diff --git a/arch/arm64/kernel/efi-header.S b/arch/arm64/kernel/efi-header.S
index ddaf57d825b5..28d8a5dca5f1 100644
--- a/arch/arm64/kernel/efi-header.S
+++ b/arch/arm64/kernel/efi-header.S
@@ -7,7 +7,27 @@
#include <linux/pe.h>
#include <linux/sizes.h>
+ .macro efi_signature_nop
+#ifdef CONFIG_EFI
+.L_head:
+ /*
+ * This ccmp instruction has no meaningful effect except that
+ * its opcode forms the magic "MZ" signature required by UEFI.
+ */
+ ccmp x18, #0, #0xd, pl
+#else
+ /*
+ * Bootloaders may inspect the opcode at the start of the kernel
+ * image to decide if the kernel is capable of booting via UEFI.
+ * So put an ordinary NOP here, not the "MZ.." pseudo-nop above.
+ */
+ nop
+#endif
+ .endm
+
.macro __EFI_PE_HEADER
+#ifdef CONFIG_EFI
+ .set .Lpe_header_offset, . - .L_head
.long PE_MAGIC
.short IMAGE_FILE_MACHINE_ARM64 // Machine
.short .Lsection_count // NumberOfSections
@@ -26,8 +46,8 @@
.long __initdata_begin - .Lefi_header_end // SizeOfCode
.long __pecoff_data_size // SizeOfInitializedData
.long 0 // SizeOfUninitializedData
- .long __efistub_efi_pe_entry - _head // AddressOfEntryPoint
- .long .Lefi_header_end - _head // BaseOfCode
+ .long __efistub_efi_pe_entry - .L_head // AddressOfEntryPoint
+ .long .Lefi_header_end - .L_head // BaseOfCode
.quad 0 // ImageBase
.long SEGMENT_ALIGN // SectionAlignment
@@ -40,10 +60,10 @@
.short 0 // MinorSubsystemVersion
.long 0 // Win32VersionValue
- .long _end - _head // SizeOfImage
+ .long _end - .L_head // SizeOfImage
// Everything before the kernel image is considered part of the header
- .long .Lefi_header_end - _head // SizeOfHeaders
+ .long .Lefi_header_end - .L_head // SizeOfHeaders
.long 0 // CheckSum
.short IMAGE_SUBSYSTEM_EFI_APPLICATION // Subsystem
.short 0 // DllCharacteristics
@@ -62,7 +82,7 @@
.quad 0 // BaseRelocationTable
#ifdef CONFIG_DEBUG_EFI
- .long .Lefi_debug_table - _head // DebugTable
+ .long .Lefi_debug_table - .L_head // DebugTable
.long .Lefi_debug_table_size
#endif
@@ -70,9 +90,9 @@
.Lsection_table:
.ascii ".text\0\0\0"
.long __initdata_begin - .Lefi_header_end // VirtualSize
- .long .Lefi_header_end - _head // VirtualAddress
+ .long .Lefi_header_end - .L_head // VirtualAddress
.long __initdata_begin - .Lefi_header_end // SizeOfRawData
- .long .Lefi_header_end - _head // PointerToRawData
+ .long .Lefi_header_end - .L_head // PointerToRawData
.long 0 // PointerToRelocations
.long 0 // PointerToLineNumbers
@@ -84,9 +104,9 @@
.ascii ".data\0\0\0"
.long __pecoff_data_size // VirtualSize
- .long __initdata_begin - _head // VirtualAddress
+ .long __initdata_begin - .L_head // VirtualAddress
.long __pecoff_data_rawsize // SizeOfRawData
- .long __initdata_begin - _head // PointerToRawData
+ .long __initdata_begin - .L_head // PointerToRawData
.long 0 // PointerToRelocations
.long 0 // PointerToLineNumbers
@@ -121,7 +141,7 @@
.long IMAGE_DEBUG_TYPE_CODEVIEW // Type
.long .Lefi_debug_entry_size // SizeOfData
.long 0 // RVA
- .long .Lefi_debug_entry - _head // FileOffset
+ .long .Lefi_debug_entry - .L_head // FileOffset
.set .Lefi_debug_table_size, . - .Lefi_debug_table
.previous
@@ -140,4 +160,7 @@
.balign SEGMENT_ALIGN
.Lefi_header_end:
+#else
+ .set .Lpe_header_offset, 0x0
+#endif
.endm
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index d8d9caf02834..c1f8f2c5be47 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -58,21 +58,11 @@
* in the entry routines.
*/
__HEAD
-_head:
/*
* DO NOT MODIFY. Image header expected by Linux boot-loaders.
*/
-#ifdef CONFIG_EFI
- /*
- * This add instruction has no meaningful effect except that
- * its opcode forms the magic "MZ" signature required by UEFI.
- */
- add x13, x18, #0x16
- b primary_entry
-#else
+ efi_signature_nop // special NOP to identity as PE/COFF executable
b primary_entry // branch to kernel start, magic
- .long 0 // reserved
-#endif
.quad 0 // Image load offset from start of RAM, little-endian
le64sym _kernel_size_le // Effective size of kernel image, little-endian
le64sym _kernel_flags_le // Informative flags, little-endian
@@ -80,14 +70,9 @@ _head:
.quad 0 // reserved
.quad 0 // reserved
.ascii ARM64_IMAGE_MAGIC // Magic number
-#ifdef CONFIG_EFI
- .long pe_header - _head // Offset to the PE header.
+ .long .Lpe_header_offset // Offset to the PE header.
-pe_header:
__EFI_PE_HEADER
-#else
- .long 0 // reserved
-#endif
__INIT