xref: /linux/arch/arm64/kernel/efi-header.S (revision 40d269c000bda9fcd276a0412a9cebd3f6e344c5)
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2013 - 2017 Linaro, Ltd.
4 * Copyright (C) 2013, 2014 Red Hat, Inc.
5 */
6
7#include <linux/pe.h>
8#include <linux/sizes.h>
9
10	.macro	efi_signature_nop
11#ifdef CONFIG_EFI
12.L_head:
13	/*
14	 * This ccmp instruction has no meaningful effect except that
15	 * its opcode forms the magic "MZ" signature required by UEFI.
16	 */
17	ccmp	x18, #0, #0xd, pl
18#else
19	/*
20	 * Bootloaders may inspect the opcode at the start of the kernel
21	 * image to decide if the kernel is capable of booting via UEFI.
22	 * So put an ordinary NOP here, not the "MZ.." pseudo-nop above.
23	 */
24	nop
25#endif
26	.endm
27
28	.macro	__EFI_PE_HEADER
29#ifdef CONFIG_EFI
30	.set	.Lpe_header_offset, . - .L_head
31	.long	PE_MAGIC
32	.short	IMAGE_FILE_MACHINE_ARM64		// Machine
33	.short	.Lsection_count				// NumberOfSections
34	.long	0 					// TimeDateStamp
35	.long	0					// PointerToSymbolTable
36	.long	0					// NumberOfSymbols
37	.short	.Lsection_table - .Loptional_header	// SizeOfOptionalHeader
38	.short	IMAGE_FILE_DEBUG_STRIPPED | \
39		IMAGE_FILE_EXECUTABLE_IMAGE | \
40		IMAGE_FILE_LINE_NUMS_STRIPPED		// Characteristics
41
42.Loptional_header:
43	.short	PE_OPT_MAGIC_PE32PLUS			// PE32+ format
44	.byte	0x02					// MajorLinkerVersion
45	.byte	0x14					// MinorLinkerVersion
46	.long	__initdata_begin - .Lefi_header_end	// SizeOfCode
47	.long	__pecoff_data_size			// SizeOfInitializedData
48	.long	0					// SizeOfUninitializedData
49	.long	__efistub_efi_pe_entry - .L_head	// AddressOfEntryPoint
50	.long	.Lefi_header_end - .L_head		// BaseOfCode
51
52	.quad	0					// ImageBase
53	.long	SEGMENT_ALIGN				// SectionAlignment
54	.long	PECOFF_FILE_ALIGNMENT			// FileAlignment
55	.short	0					// MajorOperatingSystemVersion
56	.short	0					// MinorOperatingSystemVersion
57	.short	LINUX_EFISTUB_MAJOR_VERSION		// MajorImageVersion
58	.short	LINUX_EFISTUB_MINOR_VERSION		// MinorImageVersion
59	.short	0					// MajorSubsystemVersion
60	.short	0					// MinorSubsystemVersion
61	.long	0					// Win32VersionValue
62
63	.long	_end - .L_head				// SizeOfImage
64
65	// Everything before the kernel image is considered part of the header
66	.long	.Lefi_header_end - .L_head		// SizeOfHeaders
67	.long	0					// CheckSum
68	.short	IMAGE_SUBSYSTEM_EFI_APPLICATION		// Subsystem
69	.short	IMAGE_DLL_CHARACTERISTICS_NX_COMPAT	// DllCharacteristics
70	.quad	0					// SizeOfStackReserve
71	.quad	0					// SizeOfStackCommit
72	.quad	0					// SizeOfHeapReserve
73	.quad	0					// SizeOfHeapCommit
74	.long	0					// LoaderFlags
75	.long	(.Lsection_table - .) / 8		// NumberOfRvaAndSizes
76
77	.quad	0					// ExportTable
78	.quad	0					// ImportTable
79	.quad	0					// ResourceTable
80	.quad	0					// ExceptionTable
81	.quad	0					// CertificationTable
82	.quad	0					// BaseRelocationTable
83
84#if defined(CONFIG_DEBUG_EFI) || defined(CONFIG_ARM64_BTI_KERNEL)
85	.long	.Lefi_debug_table - .L_head		// DebugTable
86	.long	.Lefi_debug_table_size
87
88	/*
89	 * The debug table is referenced via its Relative Virtual Address (RVA),
90	 * which is only defined for those parts of the image that are covered
91	 * by a section declaration. Since this header is not covered by any
92	 * section, the debug table must be emitted elsewhere. So stick it in
93	 * the .init.rodata section instead.
94	 *
95	 * Note that the payloads themselves are permitted to have zero RVAs,
96	 * which means we can simply put those right after the section headers.
97	 */
98	__INITRODATA
99
100	.align	2
101.Lefi_debug_table:
102#ifdef CONFIG_DEBUG_EFI
103	// EFI_IMAGE_DEBUG_DIRECTORY_ENTRY
104	.long	0					// Characteristics
105	.long	0					// TimeDateStamp
106	.short	0					// MajorVersion
107	.short	0					// MinorVersion
108	.long	IMAGE_DEBUG_TYPE_CODEVIEW		// Type
109	.long	.Lefi_debug_entry_size			// SizeOfData
110	.long	0					// RVA
111	.long	.Lefi_debug_entry - .L_head		// FileOffset
112#endif
113#ifdef CONFIG_ARM64_BTI_KERNEL
114	.long	0					// Characteristics
115	.long	0					// TimeDateStamp
116	.short	0					// MajorVersion
117	.short	0					// MinorVersion
118	.long	IMAGE_DEBUG_TYPE_EX_DLLCHARACTERISTICS	// Type
119	.long	4					// SizeOfData
120	.long	0					// RVA
121	.long	.Lefi_dll_characteristics_ex - .L_head	// FileOffset
122#endif
123	.set	.Lefi_debug_table_size, . - .Lefi_debug_table
124	.previous
125#endif
126
127	// Section table
128.Lsection_table:
129	.ascii	".text\0\0\0"
130	.long	__initdata_begin - .Lefi_header_end	// VirtualSize
131	.long	.Lefi_header_end - .L_head		// VirtualAddress
132	.long	__initdata_begin - .Lefi_header_end	// SizeOfRawData
133	.long	.Lefi_header_end - .L_head		// PointerToRawData
134
135	.long	0					// PointerToRelocations
136	.long	0					// PointerToLineNumbers
137	.short	0					// NumberOfRelocations
138	.short	0					// NumberOfLineNumbers
139	.long	IMAGE_SCN_CNT_CODE | \
140		IMAGE_SCN_MEM_READ | \
141		IMAGE_SCN_MEM_EXECUTE			// Characteristics
142
143	.ascii	".data\0\0\0"
144	.long	__pecoff_data_size			// VirtualSize
145	.long	__initdata_begin - .L_head		// VirtualAddress
146	.long	__pecoff_data_rawsize			// SizeOfRawData
147	.long	__initdata_begin - .L_head		// PointerToRawData
148
149	.long	0					// PointerToRelocations
150	.long	0					// PointerToLineNumbers
151	.short	0					// NumberOfRelocations
152	.short	0					// NumberOfLineNumbers
153	.long	IMAGE_SCN_CNT_INITIALIZED_DATA | \
154		IMAGE_SCN_MEM_READ | \
155		IMAGE_SCN_MEM_WRITE			// Characteristics
156
157	.set	.Lsection_count, (. - .Lsection_table) / 40
158
159#ifdef CONFIG_DEBUG_EFI
160.Lefi_debug_entry:
161	// EFI_IMAGE_DEBUG_CODEVIEW_NB10_ENTRY
162	.ascii	"NB10"					// Signature
163	.long	0					// Unknown
164	.long	0					// Unknown2
165	.long	0					// Unknown3
166
167	.asciz	VMLINUX_PATH
168
169	.set	.Lefi_debug_entry_size, . - .Lefi_debug_entry
170#endif
171#ifdef CONFIG_ARM64_BTI_KERNEL
172.Lefi_dll_characteristics_ex:
173	.long	IMAGE_DLLCHARACTERISTICS_EX_FORWARD_CFI_COMPAT
174#endif
175
176	.balign	SEGMENT_ALIGN
177.Lefi_header_end:
178#else
179	.set	.Lpe_header_offset, 0x0
180#endif
181	.endm
182