xref: /freebsd/stand/efi/loader/arch/arm64/start.S (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1/*-
2 * Copyright (c) 2014 Andrew Turner
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * We need to be a PE32+ file for EFI. On some architectures we can use
29 * objcopy to create the correct file, however on arm64 we need to do
30 * it ourselves.
31 */
32
33#define	IMAGE_FILE_MACHINE_ARM64	0xaa64
34
35#define	IMAGE_FILE_EXECUTABLE		0x0002
36
37#define	IMAGE_SCN_CNT_CODE		0x00000020
38#define	IMAGE_SCN_CNT_INITIALIZED_DATA	0x00000040
39#define	IMAGE_SCN_MEM_DISCARDABLE	0x02000000
40#define	IMAGE_SCN_MEM_EXECUTE		0x20000000
41#define	IMAGE_SCN_MEM_READ		0x40000000
42#define	IMAGE_SCN_MEM_WRITE		0x80000000
43
44	.section .peheader,"a"
45efi_start:
46	/* The MS-DOS Stub, only used to get the offset of the COFF header */
47	.ascii	"MZ"
48	.short	0
49	.space	0x38
50	.long	pe_sig - efi_start
51
52	/* The PE32 Signature. Needs to be 8-byte aligned */
53	.align	3
54pe_sig:
55	.ascii	"PE"
56	.short	0
57coff_head:
58	.short	IMAGE_FILE_MACHINE_ARM64	/* AArch64 file */
59	.short	2				/* 2 Sections */
60	.long	0				/* Timestamp */
61	.long	0				/* No symbol table */
62	.long	0				/* No symbols */
63	.short	section_table - optional_header	/* Optional header size */
64	.short	IMAGE_FILE_EXECUTABLE		/* Characteristics */
65
66optional_header:
67	.short	0x020b				/* PE32+ (64-bit addressing) */
68	.byte	0				/* Major linker version */
69	.byte	0				/* Minor linker version */
70	.long	_etext - _end_header		/* Code size */
71	.long	__data_size			/* Initialized data size */
72	.long	0				/* No uninitialized data */
73	.long	_start - efi_start		/* Entry point */
74	.long	_end_header - efi_start		/* Start of code */
75
76optional_windows_header:
77	.quad	0				/* Image base */
78	.long	4096				/* Section Alignment */
79	.long	512				/* File alignment */
80	.short	0				/* Major OS version */
81	.short	0				/* Minor OS version */
82	.short	0				/* Major image version */
83	.short	0				/* Minor image version */
84	.short	0				/* Major subsystem version */
85	.short	0				/* Minor subsystem version */
86	.long	0				/* Win32 version */
87	.long	_edata - efi_start		/* Image size */
88	.long	_end_header - efi_start		/* Header size */
89	.long	0				/* Checksum */
90	.short	0xa				/* Subsystem (EFI app) */
91	.short	0				/* DLL Characteristics */
92	.quad	0				/* Stack reserve */
93	.quad	0				/* Stack commit */
94	.quad	0				/* Heap reserve */
95	.quad	0				/* Heap commit */
96	.long	0				/* Loader flags */
97	.long	6				/* Number of RVAs */
98
99	/* RVAs: */
100	.quad	0
101	.quad	0
102	.quad	0
103	.quad	0
104	.quad	0
105	.quad	0
106
107section_table:
108	.ascii	".text"
109	.byte	0
110	.byte	0
111	.byte	0				/* Pad to 8 bytes */
112	.long	_etext - _end_header		/* Virtual size */
113	.long	_end_header - efi_start		/* Virtual address */
114	.long	_etext - _end_header		/* Size of raw data */
115	.long	_end_header - efi_start		/* Pointer to raw data */
116	.long	0				/* Pointer to relocations */
117	.long	0				/* Pointer to line numbers */
118	.short	0				/* Number of relocations */
119	.short	0				/* Number of line numbers */
120	.long	(IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE | \
121		 IMAGE_SCN_MEM_READ)		/* Characteristics */
122
123	.ascii	".data"
124	.byte	0
125	.byte	0
126	.byte	0				/* Pad to 8 bytes */
127	.long	__data_size			/* Virtual size */
128	.long	__data_start - efi_start	/* Virtual address */
129	.long	__data_size			/* Size of raw data */
130	.long	__data_start - efi_start	/* Pointer to raw data */
131	.long	0				/* Pointer to relocations */
132	.long	0				/* Pointer to line numbers */
133	.short	0				/* Number of relocations */
134	.short	0				/* Number of line numbers */
135	.long	(IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | \
136		 IMAGE_SCN_MEM_WRITE)		/* Characteristics */
137
138	.align	12
139_end_header:
140
141	.text
142	.globl	_start
143_start:
144	/* Save the boot params to the stack */
145	stp	x0, x1, [sp, #-16]!
146
147	adrp	x0, __bss_start
148	add	x0, x0, :lo12:__bss_start
149	adrp	x1, __bss_end
150	add	x1, x1, :lo12:__bss_end
151
152	b 2f
153
1541:
155	stp	xzr, xzr, [x0], #16
1562:
157	cmp	x0, x1
158	b.lo	1b
159
160	adrp	x0, ImageBase
161	add	x0, x0, :lo12:ImageBase
162	adrp	x1, _DYNAMIC
163	add	x1, x1, :lo12:_DYNAMIC
164
165	bl	self_reloc
166
167	ldp	x0, x1, [sp], #16
168
169#ifndef EFI_BOOT1
170	/*
171	 * Load the stack to use. The default stack may be too small for
172	 * the lua loader.
173	 */
174	adrp	x2, initstack_end
175	add	x2, x2, :lo12:initstack_end
176	mov	sp, x2
177#endif
178
179	bl	efi_main
180
1811:	b	1b
182
183#ifndef EFI_BOOT1
184.bss
185	.align	4
186initstack:
187	.space	(64 * 1024)
188initstack_end:
189#endif
190