usr/src/boot/sys/boot/i386/libi386/biosmem.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  * Obtain memory configuration information from the BIOS
  31  */
  32 #include <stand.h>
  33 #include <machine/pc/bios.h>
  34 #include "bootstrap.h"
  35 #include "libi386.h"
  36 #include "btxv86.h"
  37 #include "smbios.h"
  38
  39 vm_offset_t     memtop, memtop_copyin, high_heap_base;
  40 uint32_t        bios_basemem, bios_extmem, high_heap_size;
  41
  42 static struct bios_smap_xattr smap;
  43
  44 /*
  45  * Used to track which method was used to set BIOS memory
  46  * regions.
  47  */
  48 static uint8_t b_bios_probed;
  49 #define B_BASEMEM_E820  0x1
  50 #define B_BASEMEM_12    0x2
  51 #define B_EXTMEM_E820   0x4
  52 #define B_EXTMEM_E801   0x8
  53 #define B_EXTMEM_8800   0x10
  54
  55 /*
  56  * The minimum amount of memory to reserve in bios_extmem for the heap.
  57  */
  58 #define HEAP_MIN        (64 * 1024 * 1024)
  59
  60 /*
  61  * Products in this list need quirks to detect
  62  * memory correctly. You need both maker and product as
  63  * reported by smbios.
  64  */
  65 /* e820 might not return useful extended memory */
  66 #define BQ_DISTRUST_E820_EXTMEM 0x1
  67 struct bios_getmem_quirks {
  68         const char *bios_vendor;
  69         const char *maker;
  70         const char *product;
  71         int quirk;
  72 };
  73
  74 static struct bios_getmem_quirks quirks[] = {
  75         {"coreboot", "Acer", "Peppy", BQ_DISTRUST_E820_EXTMEM},
  76         {NULL, NULL, NULL, 0}
  77 };
  78
  79 static int
  80 bios_getquirks(void)
  81 {
  82         int i;
  83
  84         for (i = 0; quirks[i].quirk != 0; ++i) {
  85                 if (smbios_match(quirks[i].bios_vendor, quirks[i].maker,
  86                     quirks[i].product))
  87                         return (quirks[i].quirk);
  88         }
  89
  90         return (0);
  91 }
  92
  93 void
  94 bios_getmem(void)
  95 {
  96         uint64_t size;
  97
  98         /* Parse system memory map */
  99         v86.ebx = 0;
 100         do {
 101                 v86.ctl = V86_FLAGS;
 102                 v86.addr = 0x15;                /* int 0x15 function 0xe820 */
 103                 v86.eax = 0xe820;
 104                 v86.ecx = sizeof (struct bios_smap_xattr);
 105                 v86.edx = SMAP_SIG;
 106                 v86.es = VTOPSEG(&smap);
 107                 v86.edi = VTOPOFF(&smap);
 108                 v86int();
 109                 if ((V86_CY(v86.efl)) || (v86.eax != SMAP_SIG))
 110                         break;
 111                 /* look for a low-memory segment that's large enough */
 112                 if ((smap.type == SMAP_TYPE_MEMORY) && (smap.base == 0) &&
 113                     (smap.length >= (512 * 1024))) {
 114                         bios_basemem = smap.length;
 115                         b_bios_probed |= B_BASEMEM_E820;
 116                 }
 117
 118                 /* look for the first segment in 'extended' memory */
 119                 if ((smap.type == SMAP_TYPE_MEMORY) &&
 120                     (smap.base == 0x100000) &&
 121                     !(bios_getquirks() & BQ_DISTRUST_E820_EXTMEM)) {
 122                         bios_extmem = smap.length;
 123                         b_bios_probed |= B_EXTMEM_E820;
 124                 }
 125
 126                 /*
 127                  * Look for the highest segment in 'extended' memory beyond
 128                  * 1MB but below 4GB.
 129                  */
 130                 if ((smap.type == SMAP_TYPE_MEMORY) &&
 131                     (smap.base > 0x100000) &&
 132                     (smap.base < 0x100000000ull)) {
 133                         size = smap.length;
 134
 135                         /*
 136                          * If this segment crosses the 4GB boundary,
 137                          * truncate it.
 138                          */
 139                         if (smap.base + size > 0x100000000ull)
 140                                 size = 0x100000000ull - smap.base;
 141
 142                         /*
 143                          * To make maximum space for the kernel and the modules,
 144                          * set heap to use highest HEAP_MIN bytes below 4GB.
 145                          */
 146                         if (high_heap_base < smap.base && size >= HEAP_MIN) {
 147                                 high_heap_base = smap.base + size - HEAP_MIN;
 148                                 high_heap_size = HEAP_MIN;
 149                         }
 150                 }
 151         } while (v86.ebx != 0);
 152
 153         /* Fall back to the old compatibility function for base memory */
 154         if (bios_basemem == 0) {
 155                 v86.ctl = 0;
 156                 v86.addr = 0x12;                /* int 0x12 */
 157                 v86int();
 158
 159                 bios_basemem = (v86.eax & 0xffff) * 1024;
 160                 b_bios_probed |= B_BASEMEM_12;
 161         }
 162
 163         /*
 164          * Fall back through several compatibility functions for extended
 165          * memory.
 166          */
 167         if (bios_extmem == 0) {
 168                 v86.ctl = V86_FLAGS;
 169                 v86.addr = 0x15;                /* int 0x15 function 0xe801 */
 170                 v86.eax = 0xe801;
 171                 v86int();
 172                 if (!(V86_CY(v86.efl))) {
 173                         /*
 174                          * Clear high_heap; it may end up overlapping
 175                          * with the segment we're determining here.
 176                          * Let the default "steal stuff from top of
 177                          * bios_extmem" code below pick up on it.
 178                          */
 179                         high_heap_size = 0;
 180                         high_heap_base = 0;
 181
 182                         /*
 183                          * %cx is the number of 1KiB blocks between 1..16MiB.
 184                          * It can only be up to 0x3c00; if it's smaller then
 185                          * there's a PC AT memory hole so we can't treat
 186                          * it as contiguous.
 187                          */
 188                         bios_extmem = (v86.ecx & 0xffff) * 1024;
 189                         if (bios_extmem == (1024 * 0x3c00))
 190                                 bios_extmem += (v86.edx & 0xffff) * 64 * 1024;
 191
 192                         /* truncate bios_extmem */
 193                         if (bios_extmem > 0x3ff00000)
 194                                 bios_extmem = 0x3ff00000;
 195
 196                         b_bios_probed |= B_EXTMEM_E801;
 197                 }
 198         }
 199         if (bios_extmem == 0) {
 200                 v86.ctl = 0;
 201                 v86.addr = 0x15;                /* int 0x15 function 0x88 */
 202                 v86.eax = 0x8800;
 203                 v86int();
 204                 bios_extmem = (v86.eax & 0xffff) * 1024;
 205                 b_bios_probed |= B_EXTMEM_8800;
 206         }
 207
 208         /* Set memtop to actual top of memory */
 209         if (high_heap_size != 0) {
 210                 memtop = memtop_copyin = high_heap_base;
 211         } else {
 212                 memtop = memtop_copyin = 0x100000 + bios_extmem;
 213         }
 214
 215         /*
 216          * If we have extended memory and did not find a suitable heap
 217          * region in the SMAP, use the last HEAP_MIN of 'extended' memory as a
 218          * high heap candidate.
 219          */
 220         if (bios_extmem >= HEAP_MIN && high_heap_size < HEAP_MIN) {
 221                 high_heap_size = HEAP_MIN;
 222                 high_heap_base = memtop - HEAP_MIN;
 223                 memtop = memtop_copyin = high_heap_base;
 224         }
 225 }
 226
 227 #ifndef BOOT2
 228 static int
 229 command_biosmem(int argc, char *argv[])
 230 {
 231         int bq = bios_getquirks();
 232
 233         printf("bios_basemem: 0x%llx\n", (unsigned long long)bios_basemem);
 234         printf("bios_extmem: 0x%llx\n", (unsigned long long)bios_extmem);
 235         printf("memtop: 0x%llx\n", (unsigned long long)memtop);
 236         printf("high_heap_base: 0x%llx\n", (unsigned long long)high_heap_base);
 237         printf("high_heap_size: 0x%llx\n", (unsigned long long)high_heap_size);
 238         printf("bios_quirks: 0x%02x", bq);
 239         if (bq & BQ_DISTRUST_E820_EXTMEM)
 240                 printf(" BQ_DISTRUST_E820_EXTMEM");
 241         printf("\n");
 242         printf("b_bios_probed: 0x%02x", (int)b_bios_probed);
 243         if (b_bios_probed & B_BASEMEM_E820)
 244                 printf(" B_BASEMEM_E820");
 245         if (b_bios_probed & B_BASEMEM_12)
 246                 printf(" B_BASEMEM_12");
 247         if (b_bios_probed & B_EXTMEM_E820)
 248                 printf(" B_EXTMEM_E820");
 249         if (b_bios_probed & B_EXTMEM_E801)
 250                 printf(" B_EXTMEM_E801");
 251         if (b_bios_probed & B_EXTMEM_8800)
 252                 printf(" B_EXTMEM_8800");
 253         printf("\n");
 254
 255         return (CMD_OK);
 256 }
 257
 258 COMMAND_SET(biosmem, "biosmem", "show BIOS memory setup", command_biosmem);
 259 #endif