xref: /freebsd/stand/i386/libi386/elf64_freebsd.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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 #define __ELF_WORD_SIZE 64
29 #include <sys/param.h>
30 #include <sys/exec.h>
31 #include <sys/linker.h>
32 #include <string.h>
33 #include <machine/bootinfo.h>
34 #include <machine/elf.h>
35 #include <stand.h>
36 
37 #include "bootstrap.h"
38 #include "libi386.h"
39 #include "btxv86.h"
40 
41 static int	elf64_exec(struct preloaded_file *amp);
42 static int	elf64_obj_exec(struct preloaded_file *amp);
43 
44 struct file_format amd64_elf = { elf64_loadfile, elf64_exec };
45 struct file_format amd64_elf_obj = { elf64_obj_loadfile, elf64_obj_exec };
46 
47 #define PG_V	0x001
48 #define PG_RW	0x002
49 #define PG_PS	0x080
50 
51 typedef uint64_t p4_entry_t;
52 typedef uint64_t p3_entry_t;
53 typedef uint64_t p2_entry_t;
54 extern p4_entry_t PT4[];
55 extern p3_entry_t PT3[];
56 extern p2_entry_t PT2[];
57 
58 uint32_t entry_hi;
59 uint32_t entry_lo;
60 
61 extern void amd64_tramp();
62 
63 /*
64  * There is an ELF kernel and one or more ELF modules loaded.
65  * We wish to start executing the kernel image, so make such
66  * preparations as are required, and do so.
67  */
68 static int
69 elf64_exec(struct preloaded_file *fp)
70 {
71     struct file_metadata	*md;
72     Elf_Ehdr 			*ehdr;
73     vm_offset_t			modulep, kernend;
74     int				err;
75     int				i;
76 
77     if ((md = file_findmetadata(fp, MODINFOMD_ELFHDR)) == NULL)
78 	return(EFTYPE);
79     ehdr = (Elf_Ehdr *)&(md->md_data);
80 
81     err = bi_load64(fp->f_args, &modulep, &kernend, 1);
82     if (err != 0)
83 	return(err);
84 
85     bzero(PT4, PAGE_SIZE);
86     bzero(PT3, PAGE_SIZE);
87     bzero(PT2, PAGE_SIZE);
88 
89     /*
90      * This is kinda brutal, but every single 1GB VM memory segment points to
91      * the same first 1GB of physical memory.  But it is more than adequate.
92      */
93     for (i = 0; i < 512; i++) {
94 	/* Each slot of the level 4 pages points to the same level 3 page */
95 	PT4[i] = (p4_entry_t)VTOP((uintptr_t)&PT3[0]);
96 	PT4[i] |= PG_V | PG_RW;
97 
98 	/* Each slot of the level 3 pages points to the same level 2 page */
99 	PT3[i] = (p3_entry_t)VTOP((uintptr_t)&PT2[0]);
100 	PT3[i] |= PG_V | PG_RW;
101 
102 	/* The level 2 page slots are mapped with 2MB pages for 1GB. */
103 	PT2[i] = i * (2 * 1024 * 1024);
104 	PT2[i] |= PG_V | PG_RW | PG_PS;
105     }
106 
107     entry_lo = ehdr->e_entry & 0xffffffff;
108     entry_hi = (ehdr->e_entry >> 32) & 0xffffffff;
109 #ifdef DEBUG
110     printf("Start @ %#llx ...\n", ehdr->e_entry);
111 #endif
112 
113     dev_cleanup();
114     __exec((void *)VTOP(amd64_tramp), modulep, kernend);
115 
116     panic("exec returned");
117 }
118 
119 static int
120 elf64_obj_exec(struct preloaded_file *fp)
121 {
122 	return (EFTYPE);
123 }
124