2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2005 Olivier Houchard. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 #include <machine/asm.h>
30 #include <sys/param.h>
33 #include <sys/elf64.h>
35 #include <sys/elf32.h>
39 * Since we are compiled outside of the normal kernel build process, we
40 * need to include opt_global.h manually.
42 #include "opt_global.h"
44 #include <machine/elf.h>
45 #include <machine/cpufunc.h>
46 #include <machine/stdarg.h>
49 #error Kernel name not provided
52 extern char kernel_start[];
53 extern char kernel_end[];
55 static __inline void *
56 memcpy(void *dst, const void *src, size_t len)
62 if (0 && len >= 4 && !((vm_offset_t)d & 3) &&
63 !((vm_offset_t)s & 3)) {
64 *(uint32_t *)d = *(uint32_t *)s;
77 bzero(void *addr, size_t count)
79 char *tmp = (char *)addr;
82 if (count >= 4 && !((vm_offset_t)tmp & 3)) {
95 * Convert number to pointer, truncate on 64->32 case, sign extend
98 #define mkptr(x) ((void *)(intptr_t)(int)(x))
101 * Relocate PT_LOAD segements of kernel ELF image to their respective
102 * virtual addresses and return entry point
105 load_kernel(void * kstart)
109 Elf64_Phdr phdr[64] /* XXX */;
110 Elf64_Shdr shdr[64] /* XXX */;
113 Elf32_Phdr phdr[64] /* XXX */;
114 Elf32_Shdr shdr[64] /* XXX */;
118 vm_offset_t loadend = 0;
120 int symtabindex = -1;
121 int symstrindex = -1;
125 eh = (Elf64_Ehdr *)kstart;
127 eh = (Elf32_Ehdr *)kstart;
129 entry_point = mkptr(eh->e_entry);
130 memcpy(phdr, (void *)(kstart + eh->e_phoff),
131 eh->e_phnum * sizeof(phdr[0]));
133 memcpy(shdr, (void *)(kstart + eh->e_shoff),
134 sizeof(*shdr) * eh->e_shnum);
136 if (eh->e_shnum * eh->e_shentsize != 0 && eh->e_shoff != 0) {
137 for (i = 0; i < eh->e_shnum; i++) {
138 if (shdr[i].sh_type == SHT_SYMTAB) {
140 * XXX: check if .symtab is in PT_LOAD?
142 if (shdr[i].sh_offset != 0 &&
143 shdr[i].sh_size != 0) {
145 symstrindex = shdr[i].sh_link;
152 * Copy loadable segments
154 for (i = 0; i < eh->e_phnum; i++) {
157 if (phdr[i].p_type != PT_LOAD)
160 memcpy(mkptr(phdr[i].p_vaddr),
161 (void*)(kstart + phdr[i].p_offset), phdr[i].p_filesz);
163 /* Clean space from oversized segments, eg: bss. */
164 if (phdr[i].p_filesz < phdr[i].p_memsz)
165 bzero(mkptr(phdr[i].p_vaddr + phdr[i].p_filesz),
166 phdr[i].p_memsz - phdr[i].p_filesz);
168 if (loadend < phdr[i].p_vaddr + phdr[i].p_memsz)
169 loadend = phdr[i].p_vaddr + phdr[i].p_memsz;
172 /* Now grab the symbol tables. */
173 lastaddr = (intptr_t)(int)loadend;
174 if (symtabindex >= 0 && symstrindex >= 0) {
176 memcpy((void *)lastaddr, &tmp, sizeof(tmp));
177 lastaddr += sizeof(Elf_Size);
178 tmp = shdr[symtabindex].sh_size +
179 shdr[symstrindex].sh_size + 2*sizeof(Elf_Size);
180 memcpy((void *)lastaddr, &tmp, sizeof(tmp));
181 lastaddr += sizeof(Elf_Size);
183 tmp = shdr[symtabindex].sh_size;
184 memcpy((void *)lastaddr, &tmp, sizeof(tmp));
185 lastaddr += sizeof(shdr[symtabindex].sh_size);
187 memcpy((void*)lastaddr,
188 shdr[symtabindex].sh_offset + kstart,
189 shdr[symtabindex].sh_size);
190 lastaddr += shdr[symtabindex].sh_size;
193 tmp = shdr[symstrindex].sh_size;
194 memcpy((void *)lastaddr, &tmp, sizeof(tmp));
195 lastaddr += sizeof(shdr[symstrindex].sh_size);
198 memcpy((void*)lastaddr,
199 shdr[symstrindex].sh_offset + kstart,
200 shdr[symstrindex].sh_size);
202 /* Do not take any chances */
204 memcpy((void *)lastaddr, &tmp, sizeof(tmp));
211 _startC(register_t a0, register_t a1, register_t a2, register_t a3)
215 void (*entry_point)(register_t, register_t, register_t, register_t);
218 * Relocate segment to the predefined memory location
219 * Most likely it will be KSEG0/KSEG1 address
221 entry_point = load_kernel(kernel_start);
223 /* Pass saved registers to original _start */
224 entry_point(a0, a1, a2, a3);