1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2020 Mitchell Horne <mhorne@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 */
29
30#include <machine/asm.h>
31
32/*
33 * We need to be a PE32+ file for EFI. On some architectures we can use
34 * objcopy to create the correct file, however on RISC-V we need to do
35 * it ourselves.
36 */
37
38#define	IMAGE_FILE_MACHINE_RISCV64	0x5064
39
40#define	IMAGE_SCN_CNT_CODE		0x00000020
41#define	IMAGE_SCN_CNT_INITIALIZED_DATA	0x00000040
42#define	IMAGE_SCN_MEM_DISCARDABLE	0x02000000
43#define	IMAGE_SCN_MEM_EXECUTE		0x20000000
44#define	IMAGE_SCN_MEM_READ		0x40000000
45
46	.section .peheader,"a"
47efi_start:
48	/* The MS-DOS Stub, only used to get the offset of the COFF header */
49	.ascii	"MZ"
50	.short	0
51	.space	0x38
52	.long	pe_sig - efi_start
53
54	/* The PE32 Signature. Needs to be 8-byte aligned */
55	.align	3
56pe_sig:
57	.ascii	"PE"
58	.short	0
59coff_head:
60	.short	IMAGE_FILE_MACHINE_RISCV64	/* RISC-V 64 file */
61	.short	2				/* 2 Sections */
62	.long	0				/* Timestamp */
63	.long	0				/* No symbol table */
64	.long	0				/* No symbols */
65	.short	section_table - optional_header	/* Optional header size */
66	.short	0	/* Characteristics TODO: Fill in */
67
68optional_header:
69	.short	0x020b				/* PE32+ (64-bit addressing) */
70	.byte	0				/* Major linker version */
71	.byte	0				/* Minor linker version */
72	.long	_edata - _end_header		/* Code size */
73	.long	0				/* No initialized data */
74	.long	0				/* No uninitialized data */
75	.long	_start - efi_start		/* Entry point */
76	.long	_end_header - efi_start		/* Start of code */
77
78optional_windows_header:
79	.quad	0				/* Image base */
80	.long	32				/* Section Alignment */
81	.long	8				/* File alignment */
82	.short	0				/* Major OS version */
83	.short	0				/* Minor OS version */
84	.short	0				/* Major image version */
85	.short	0				/* Minor image version */
86	.short	0				/* Major subsystem version */
87	.short	0				/* Minor subsystem version */
88	.long	0				/* Win32 version */
89	.long	_edata - efi_start		/* Image size */
90	.long	_end_header - efi_start		/* Header size */
91	.long	0				/* Checksum */
92	.short	0xa				/* Subsystem (EFI app) */
93	.short	0				/* DLL Characteristics */
94	.quad	0				/* Stack reserve */
95	.quad	0				/* Stack commit */
96	.quad	0				/* Heap reserve */
97	.quad	0				/* Heap commit */
98	.long	0				/* Loader flags */
99	.long	6				/* Number of RVAs */
100
101	/* RVAs: */
102	.quad	0
103	.quad	0
104	.quad	0
105	.quad	0
106	.quad	0
107	.quad	0
108
109section_table:
110	/* We need a .reloc section for EFI */
111	.ascii	".reloc"
112	.byte	0
113	.byte	0				/* Pad to 8 bytes */
114	.long	0				/* Virtual size */
115	.long	0				/* Virtual address */
116	.long	0				/* Size of raw data */
117	.long	0				/* Pointer to raw data */
118	.long	0				/* Pointer to relocations */
119	.long	0				/* Pointer to line numbers */
120	.short	0				/* Number of relocations */
121	.short	0				/* Number of line numbers */
122	.long	(IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | \
123		 IMAGE_SCN_MEM_DISCARDABLE)	/* Characteristics */
124
125	/* The contents of the loader */
126	.ascii	".text"
127	.byte	0
128	.byte	0
129	.byte	0				/* Pad to 8 bytes */
130	.long	_edata - _end_header		/* Virtual size */
131	.long	_end_header - efi_start		/* Virtual address */
132	.long	_edata - _end_header		/* Size of raw data */
133	.long	_end_header - efi_start		/* Pointer to raw data */
134	.long	0				/* Pointer to relocations */
135	.long	0				/* Pointer to line numbers */
136	.short	0				/* Number of relocations */
137	.short	0				/* Number of line numbers */
138	.long	(IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE | \
139		 IMAGE_SCN_MEM_READ)		/* Characteristics */
140_end_header:
141
142	.text
143	.globl	_start
144_start:
145	/* Save the boot params to the stack */
146	addi	sp, sp, -16
147	sd	a0, 0(sp)
148	sd	a1, 8(sp)
149
150	/* Zero the BSS */
151	lla	t0, __bss_start
152	lla	t1, __bss_end
153
1541:	sd	zero, 0(t0)
155	addi	t0, t0, 8
156	bltu	t0, t1, 1b
157
158	lla	a0, ImageBase
159	lla	a1, _DYNAMIC
160	call	_C_LABEL(self_reloc)
161
162	ld	a1, 8(sp)
163	ld	a0, 0(sp)
164	tail	_C_LABEL(efi_main)
165
166	/* NOTREACHED */
1672:	wfi
168	j	2b
169