usr/src/boot/sys/boot/i386/libi386/i386_copy.c

   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
  29 /*
  30  * MD primitives supporting placement of module data
  31  *
  32  * XXX should check load address/size against memory top.
  33  */
  34 #include <stand.h>
  35 #include <sys/param.h>
  36 #include <sys/multiboot2.h>
  37 #include <machine/metadata.h>
  38 #include <machine/pc/bios.h>
  39 #include "libi386.h"
  40 #include "btxv86.h"
  41 #include "bootstrap.h"
  42
  43 /*
  44  * Verify the address is not in use by existing modules.
  45  */
  46 static vm_offset_t
  47 addr_verify(struct preloaded_file *fp, vm_offset_t addr, size_t size)
  48 {
  49         vm_offset_t f_addr;
  50
  51         while (fp != NULL) {
  52                 f_addr = fp->f_addr;
  53
  54                 if ((f_addr <= addr) &&
  55                      (f_addr + fp->f_size >= addr)) {
  56                         return (0);
  57                 }
  58                 if ((f_addr >= addr) && (f_addr <= addr + size)) {
  59                         return (0);
  60                 }
  61                 fp = fp->f_next;
  62         }
  63         return (addr);
  64 }
  65
  66 /*
  67  * Find smap entry above 1MB, able to contain size bytes from addr.
  68  */
  69 static vm_offset_t
  70 smap_find(struct bios_smap *smap, int smaplen, vm_offset_t addr, size_t size)
  71 {
  72         int i;
  73
  74         for (i = 0; i < smaplen; i++) {
  75                 if (smap[i].type != SMAP_TYPE_MEMORY)
  76                         continue;
  77
  78                 /* We do not want address below 1MB. */
  79                 if (smap[i].base < 0x100000)
  80                         continue;
  81
  82                 /* Do we fit into current entry? */
  83                 if ((smap[i].base <= addr) &&
  84                     (smap[i].base + smap[i].length >= addr + size)) {
  85                         return (addr);
  86                 }
  87
  88                 /* Do we fit into new entry? */
  89                 if ((smap[i].base > addr) && (smap[i].length >= size)) {
  90                         return (smap[i].base);
  91                 }
  92         }
  93         return (0);
  94 }
  95
  96 /*
  97  * Find usable address for loading. The address for the kernel is fixed, as
  98  * it is determined by kernel linker map (dboot PT_LOAD address).
  99  * For modules, we need to consult smap, the module address has to be
 100  * aligned to page boundary and we have to fit into smap entry.
 101  */
 102 vm_offset_t
 103 i386_loadaddr(u_int type, void *data, vm_offset_t addr)
 104 {
 105         struct stat st;
 106         size_t size, smaplen;
 107         struct preloaded_file *fp, *mfp;
 108         struct file_metadata *md;
 109         struct bios_smap *smap;
 110         vm_offset_t off;
 111
 112         /*
 113          * For now, assume we have memory for the kernel, the
 114          * required map is [1MB..) This assumption should be safe with x86 BIOS.
 115          */
 116         if (type == LOAD_KERN)
 117                 return (addr);
 118
 119         if (addr == 0)
 120                 return (addr);  /* nothing to do */
 121
 122         if (type == LOAD_ELF)
 123                 return (0);     /* not supported */
 124
 125         if (type == LOAD_MEM) {
 126                 size = *(size_t *)data;
 127         } else {
 128                 stat(data, &st);
 129                 size = st.st_size;
 130         }
 131
 132         /*
 133          * Find our kernel, from it we will find the smap and the list of
 134          * loaded modules.
 135          */
 136         fp = file_findfile(NULL, NULL);
 137         if (fp == NULL)
 138                 return (0);
 139         md = file_findmetadata(fp, MODINFOMD_SMAP);
 140         if (md == NULL)
 141                 return (0);
 142
 143         smap = (struct bios_smap *)md->md_data;
 144         smaplen = md->md_size / sizeof(struct bios_smap);
 145
 146         /* Start from the end of the kernel. */
 147         mfp = fp;
 148         do {
 149                 if (mfp == NULL) {
 150                         off = roundup2(addr + 1, MULTIBOOT_MOD_ALIGN);
 151                 } else {
 152                         off = roundup2(mfp->f_addr + mfp->f_size + 1,
 153                             MULTIBOOT_MOD_ALIGN);
 154                 }
 155                 off = smap_find(smap, smaplen, off, size);
 156                 off = addr_verify(fp, off, size);
 157                 if (off != 0)
 158                         break;
 159
 160                 if (mfp == NULL)
 161                         break;
 162                 mfp = mfp->f_next;
 163         } while (off == 0);
 164
 165         return (off);
 166 }
 167
 168 ssize_t
 169 i386_copyin(const void *src, vm_offset_t dest, const size_t len)
 170 {
 171         if (dest + len >= memtop) {
 172                 errno = EFBIG;
 173                 return (-1);
 174         }
 175
 176         bcopy(src, PTOV(dest), len);
 177         return (len);
 178 }
 179
 180 ssize_t
 181 i386_copyout(const vm_offset_t src, void *dest, const size_t len)
 182 {
 183         if (src + len >= memtop) {
 184                 errno = EFBIG;
 185                 return (-1);
 186         }
 187
 188         bcopy(PTOV(src), dest, len);
 189         return (len);
 190 }
 191
 192
 193 ssize_t
 194 i386_readin(const int fd, vm_offset_t dest, const size_t len)
 195 {
 196         if (dest + len >= memtop_copyin) {
 197                 errno = EFBIG;
 198                 return (-1);
 199         }
 200
 201         return (read(fd, PTOV(dest), len));
 202 }