1 /* $NetBSD: exec_multiboot1.c,v 1.3 2019/10/18 01:09:46 manu Exp $ */
2 
3 /*
4  * Copyright (c) 2019 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/param.h>
30 #include <sys/reboot.h>
31 
32 #include <i386/multiboot.h>
33 
34 #include <lib/libsa/stand.h>
35 #include <lib/libkern/libkern.h>
36 
37 #include "loadfile.h"
38 #include "libi386.h"
39 #include "bootinfo.h"
40 #include "bootmod.h"
41 #include "vbe.h"
42 
43 extern struct btinfo_modulelist *btinfo_modulelist;
44 
45 void
ksyms_addr_set(void * ehdr,void * shdr,void * symbase)46 ksyms_addr_set(void *ehdr, void *shdr, void *symbase)
47 {
48           int class;
49           Elf32_Ehdr *ehdr32 = NULL;
50           Elf64_Ehdr *ehdr64 = NULL;
51           uint64_t shnum;
52           int i;
53 
54           class = ((Elf_Ehdr *)ehdr)->e_ident[EI_CLASS];
55 
56         switch (class) {
57         case ELFCLASS32:
58                 ehdr32 = (Elf32_Ehdr *)ehdr;
59                 shnum = ehdr32->e_shnum;
60                 break;
61         case ELFCLASS64:
62                 ehdr64 = (Elf64_Ehdr *)ehdr;
63                 shnum = ehdr64->e_shnum;
64                 break;
65         default:
66                     panic("Unexpected ELF class");
67                     break;
68         }
69 
70           for (i = 0; i < shnum; i++) {
71                     Elf64_Shdr *shdrp64 = NULL;
72                     Elf32_Shdr *shdrp32 = NULL;
73                     uint64_t shtype, shaddr, shsize, shoffset;
74 
75                     switch(class) {
76                     case ELFCLASS64:
77                               shdrp64 = &((Elf64_Shdr *)shdr)[i];
78                               shtype = shdrp64->sh_type;
79                               shaddr = shdrp64->sh_addr;
80                               shsize = shdrp64->sh_size;
81                               shoffset = shdrp64->sh_offset;
82                               break;
83                     case ELFCLASS32:
84                               shdrp32 = &((Elf32_Shdr *)shdr)[i];
85                               shtype = shdrp32->sh_type;
86                               shaddr = shdrp32->sh_addr;
87                               shsize = shdrp32->sh_size;
88                               shoffset = shdrp32->sh_offset;
89                               break;
90                     default:
91                               panic("Unexpected ELF class");
92                               break;
93                     }
94 
95                     if (shtype != SHT_SYMTAB && shtype != SHT_STRTAB)
96                               continue;
97 
98                     if (shaddr != 0 || shsize == 0)
99                               continue;
100 
101                     shaddr = (uint64_t)(uintptr_t)(symbase + shoffset);
102 
103                     switch(class) {
104                     case ELFCLASS64:
105                               shdrp64->sh_addr = shaddr;
106                               break;
107                     case ELFCLASS32:
108                               shdrp32->sh_addr = shaddr;
109                               break;
110                     default:
111                               panic("Unexpected ELF class");
112                               break;
113                     }
114           }
115 
116           return;
117 }
118 
119 static int
exec_multiboot1(struct multiboot_package * mbp)120 exec_multiboot1(struct multiboot_package *mbp)
121 {
122           struct multiboot_info *mbi;
123           struct multiboot_module *mbm;
124           int i, len;
125           char *cmdline;
126           struct bi_modulelist_entry *bim;
127 
128           mbi = alloc(sizeof(struct multiboot_info));
129           mbi->mi_flags = MULTIBOOT_INFO_HAS_MEMORY;
130 
131           mbi->mi_mem_upper = mbp->mbp_extmem;
132           mbi->mi_mem_lower = mbp->mbp_basemem;
133 
134           if (mbp->mbp_args) {
135                     mbi->mi_flags |= MULTIBOOT_INFO_HAS_CMDLINE;
136                     len = strlen(mbp->mbp_file) + 1 + strlen(mbp->mbp_args) + 1;
137                     cmdline = alloc(len);
138                     snprintf(cmdline, len, "%s %s", mbp->mbp_file, mbp->mbp_args);
139                     mbi->mi_cmdline = (char *) vtophys(cmdline);
140           }
141 
142           /* pull in any modules if necessary */
143           if (btinfo_modulelist) {
144                     mbm = alloc(sizeof(struct multiboot_module) *
145                                            btinfo_modulelist->num);
146 
147                     bim = (struct bi_modulelist_entry *)
148                       (((char *) btinfo_modulelist) +
149                        sizeof(struct btinfo_modulelist));
150                     for (i = 0; i < btinfo_modulelist->num; i++) {
151                               mbm[i].mmo_start = bim->base;
152                               mbm[i].mmo_end = bim->base + bim->len;
153                               mbm[i].mmo_string = (char *)vtophys(bim->path);
154                               mbm[i].mmo_reserved = 0;
155                               bim++;
156                     }
157                     mbi->mi_flags |= MULTIBOOT_INFO_HAS_MODS;
158                     mbi->mi_mods_count = btinfo_modulelist->num;
159                     mbi->mi_mods_addr = vtophys(mbm);
160           }
161 
162           if (mbp->mbp_marks[MARK_SYM] != 0) {
163                     Elf32_Ehdr ehdr;
164                     void *shbuf;
165                     size_t shlen;
166                     u_long shaddr;
167 
168                     pvbcopy((void *)mbp->mbp_marks[MARK_SYM], &ehdr, sizeof(ehdr));
169 
170                     if (memcmp(&ehdr.e_ident, ELFMAG, SELFMAG) != 0)
171                               goto skip_ksyms;
172 
173                     shaddr = mbp->mbp_marks[MARK_SYM] + ehdr.e_shoff;
174 
175                     shlen = ehdr.e_shnum * ehdr.e_shentsize;
176                     shbuf = alloc(shlen);
177 
178                     pvbcopy((void *)shaddr, shbuf, shlen);
179                     ksyms_addr_set(&ehdr, shbuf,
180                         (void *)(KERNBASE + mbp->mbp_marks[MARK_SYM]));
181                     vpbcopy(shbuf, (void *)shaddr, shlen);
182 
183                     dealloc(shbuf, shlen);
184 
185                     mbi->mi_elfshdr_num = ehdr.e_shnum;
186                     mbi->mi_elfshdr_size = ehdr.e_shentsize;
187                     mbi->mi_elfshdr_addr = shaddr;
188                     mbi->mi_elfshdr_shndx = ehdr.e_shstrndx;
189 
190                     mbi->mi_flags |= MULTIBOOT_INFO_HAS_ELF_SYMS;
191           }
192 skip_ksyms:
193 
194 #ifdef DEBUG
195           printf("Start @ 0x%lx [%ld=0x%lx-0x%lx]...\n",
196               mbp->mbp_marks[MARK_ENTRY],
197               mbp->mbp_marks[MARK_NSYM],
198               mbp->mbp_marks[MARK_SYM],
199               mbp->mbp_marks[MARK_END]);
200 #endif
201 
202           /* Does not return */
203           multiboot(mbp->mbp_marks[MARK_ENTRY], vtophys(mbi),
204               x86_trunc_page(mbi->mi_mem_lower * 1024), MULTIBOOT_INFO_MAGIC);
205 
206           return 0;
207 }
208 
209 static void
cleanup_multiboot1(struct multiboot_package * mbp)210 cleanup_multiboot1(struct multiboot_package *mbp)
211 {
212           dealloc(mbp->mbp_header, sizeof(*mbp->mbp_header));
213           dealloc(mbp, sizeof(*mbp));
214 
215           return;
216 }
217 
218 
219 struct multiboot_package *
probe_multiboot1(const char * path)220 probe_multiboot1(const char *path)
221 {
222           int fd = -1;
223           size_t i;
224           char buf[8192 + sizeof(struct multiboot_header)];
225           ssize_t readen;
226           struct multiboot_package *mbp = NULL;
227 
228           if ((fd = open(path, 0)) == -1)
229                     goto out;
230 
231           readen = read(fd, buf, sizeof(buf));
232           if (readen < sizeof(struct multiboot_header))
233                     goto out;
234 
235           for (i = 0; i < readen; i += 4) {
236                     struct multiboot_header *mbh;
237 
238                     mbh = (struct multiboot_header *)(buf + i);
239 
240                     if (mbh->mh_magic != MULTIBOOT_HEADER_MAGIC)
241                               continue;
242 
243                     if (mbh->mh_magic + mbh->mh_flags + mbh->mh_checksum)
244                               continue;
245 
246                     mbp = alloc(sizeof(*mbp));
247                     mbp->mbp_version    = 1;
248                     mbp->mbp_file                 = path;
249                     mbp->mbp_header               = alloc(sizeof(*mbp->mbp_header));
250                     mbp->mbp_probe                = *probe_multiboot1;
251                     mbp->mbp_exec                 = *exec_multiboot1;
252                     mbp->mbp_cleanup    = *cleanup_multiboot1;
253 
254                     memcpy(mbp->mbp_header, mbh, sizeof(*mbp->mbp_header));
255 
256                     goto out;
257 
258           }
259 
260 out:
261           if (fd != -1)
262                     close(fd);
263 
264           return mbp;
265 }
266