1 /*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
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 #include <sys/param.h>
28 #include <sys/exec.h>
29 #include <sys/linker.h>
30 #include <string.h>
31 #define _MACHINE_ELF_WANT_32BIT
32 #include <i386/include/bootinfo.h>
33 #include <i386/include/elf.h>
34 #include <stand.h>
35
36 #include "bootstrap.h"
37 #include "libuserboot.h"
38
39 static int elf32_exec(struct preloaded_file *amp);
40 static int elf32_obj_exec(struct preloaded_file *amp);
41
42 struct file_format i386_elf = { elf32_loadfile, elf32_exec };
43 struct file_format i386_elf_obj = { elf32_obj_loadfile, elf32_obj_exec };
44
45 #define GUEST_STACK 0x1000 /* Initial stack base */
46 #define GUEST_GDT 0x3000 /* Address of initial GDT */
47
48 /*
49 * There is an ELF kernel and one or more ELF modules loaded.
50 * We wish to start executing the kernel image, so make such
51 * preparations as are required, and do so.
52 */
53 static int
elf32_exec(struct preloaded_file * fp)54 elf32_exec(struct preloaded_file *fp)
55 {
56 struct file_metadata *md;
57 Elf_Ehdr *ehdr;
58 vm_offset_t entry, bootinfop, modulep, kernend;
59 int boothowto, err, bootdev;
60 uint32_t stack[1024], *sp;
61
62
63 if ((md = file_findmetadata(fp, MODINFOMD_ELFHDR)) == NULL)
64 return(EFTYPE);
65 ehdr = (Elf_Ehdr *)&(md->md_data);
66
67 err = bi_load32(fp->f_args, &boothowto, &bootdev, &bootinfop, &modulep, &kernend);
68 if (err != 0)
69 return(err);
70 entry = ehdr->e_entry & 0xffffff;
71
72 #ifdef DEBUG
73 printf("Start @ 0x%lx ...\n", entry);
74 #endif
75
76 dev_cleanup();
77
78 /*
79 * Build a scratch stack at physical 0x1000
80 */
81 memset(stack, 0, sizeof(stack));
82 sp = (uint32_t *)((char *)stack + sizeof(stack));
83 *--sp = kernend;
84 *--sp = modulep;
85 *--sp = bootinfop;
86 *--sp = 0;
87 *--sp = 0;
88 *--sp = 0;
89 *--sp = bootdev;
90 *--sp = boothowto;
91
92 /*
93 * Fake return address to mimic "new" boot blocks. For more
94 * details see recover_bootinfo in locore.S.
95 */
96 *--sp = 0xbeefface;
97 CALLBACK(copyin, stack, GUEST_STACK, sizeof(stack));
98 CALLBACK(setreg, 4, (char *)sp - (char *)stack + GUEST_STACK);
99
100 CALLBACK(setgdt, GUEST_GDT, 8 * 4 - 1);
101
102 CALLBACK(exec, entry);
103
104 panic("exec returned");
105 }
106
107 static int
elf32_obj_exec(struct preloaded_file * fp)108 elf32_obj_exec(struct preloaded_file *fp)
109 {
110 return (EFTYPE);
111 }
112