xref: /freebsd/stand/i386/libi386/elf64_freebsd.c (revision 2b8331622f0b212cf3bb4fc4914a501e5321d506)
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/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #define __ELF_WORD_SIZE 64
31 #include <sys/param.h>
32 #include <sys/exec.h>
33 #include <sys/linker.h>
34 #include <string.h>
35 #include <machine/bootinfo.h>
36 #include <machine/elf.h>
37 #include <stand.h>
38 
39 #include "bootstrap.h"
40 #include "libi386.h"
41 #include "btxv86.h"
42 
43 static int	elf64_exec(struct preloaded_file *amp);
44 static int	elf64_obj_exec(struct preloaded_file *amp);
45 
46 struct file_format amd64_elf = { elf64_loadfile, elf64_exec };
47 struct file_format amd64_elf_obj = { elf64_obj_loadfile, elf64_obj_exec };
48 
49 #define PG_V	0x001
50 #define PG_RW	0x002
51 #define PG_PS	0x080
52 
53 typedef uint64_t p4_entry_t;
54 typedef uint64_t p3_entry_t;
55 typedef uint64_t p2_entry_t;
56 extern p4_entry_t PT4[];
57 extern p3_entry_t PT3[];
58 extern p2_entry_t PT2[];
59 
60 uint32_t entry_hi;
61 uint32_t entry_lo;
62 
63 extern void amd64_tramp();
64 
65 /*
66  * There is an ELF kernel and one or more ELF modules loaded.
67  * We wish to start executing the kernel image, so make such
68  * preparations as are required, and do so.
69  */
70 static int
71 elf64_exec(struct preloaded_file *fp)
72 {
73     struct file_metadata	*md;
74     Elf_Ehdr 			*ehdr;
75     vm_offset_t			modulep, kernend;
76     int				err;
77     int				i;
78 
79     if ((md = file_findmetadata(fp, MODINFOMD_ELFHDR)) == NULL)
80 	return(EFTYPE);
81     ehdr = (Elf_Ehdr *)&(md->md_data);
82 
83     err = bi_load64(fp->f_args, &modulep, &kernend, 1);
84     if (err != 0)
85 	return(err);
86 
87     bzero(PT4, PAGE_SIZE);
88     bzero(PT3, PAGE_SIZE);
89     bzero(PT2, PAGE_SIZE);
90 
91     /*
92      * This is kinda brutal, but every single 1GB VM memory segment points to
93      * the same first 1GB of physical memory.  But it is more than adequate.
94      */
95     for (i = 0; i < 512; i++) {
96 	/* Each slot of the level 4 pages points to the same level 3 page */
97 	PT4[i] = (p4_entry_t)VTOP((uintptr_t)&PT3[0]);
98 	PT4[i] |= PG_V | PG_RW;
99 
100 	/* Each slot of the level 3 pages points to the same level 2 page */
101 	PT3[i] = (p3_entry_t)VTOP((uintptr_t)&PT2[0]);
102 	PT3[i] |= PG_V | PG_RW;
103 
104 	/* The level 2 page slots are mapped with 2MB pages for 1GB. */
105 	PT2[i] = i * (2 * 1024 * 1024);
106 	PT2[i] |= PG_V | PG_RW | PG_PS;
107     }
108 
109     entry_lo = ehdr->e_entry & 0xffffffff;
110     entry_hi = (ehdr->e_entry >> 32) & 0xffffffff;
111 #ifdef DEBUG
112     printf("Start @ %#llx ...\n", ehdr->e_entry);
113 #endif
114 
115     dev_cleanup();
116     __exec((void *)VTOP(amd64_tramp), modulep, kernend);
117 
118     panic("exec returned");
119 }
120 
121 static int
122 elf64_obj_exec(struct preloaded_file *fp)
123 {
124 	return (EFTYPE);
125 }
126