| 1 | /* $Id: boot.c 98103 2023-01-17 14:15:46Z vboxsync $ */
|
|---|
| 2 | /** @file
|
|---|
| 3 | * PC BIOS - ???
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | /*
|
|---|
| 7 | * Copyright (C) 2006-2023 Oracle and/or its affiliates.
|
|---|
| 8 | *
|
|---|
| 9 | * This file is part of VirtualBox base platform packages, as
|
|---|
| 10 | * available from https://www.virtualbox.org.
|
|---|
| 11 | *
|
|---|
| 12 | * This program is free software; you can redistribute it and/or
|
|---|
| 13 | * modify it under the terms of the GNU General Public License
|
|---|
| 14 | * as published by the Free Software Foundation, in version 3 of the
|
|---|
| 15 | * License.
|
|---|
| 16 | *
|
|---|
| 17 | * This program is distributed in the hope that it will be useful, but
|
|---|
| 18 | * WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|---|
| 20 | * General Public License for more details.
|
|---|
| 21 | *
|
|---|
| 22 | * You should have received a copy of the GNU General Public License
|
|---|
| 23 | * along with this program; if not, see <https://www.gnu.org/licenses>.
|
|---|
| 24 | *
|
|---|
| 25 | * SPDX-License-Identifier: GPL-3.0-only
|
|---|
| 26 | * --------------------------------------------------------------------
|
|---|
| 27 | *
|
|---|
| 28 | * This code is based on:
|
|---|
| 29 | *
|
|---|
| 30 | * ROM BIOS for use with Bochs/Plex86/QEMU emulation environment
|
|---|
| 31 | *
|
|---|
| 32 | * Copyright (C) 2002 MandrakeSoft S.A.
|
|---|
| 33 | *
|
|---|
| 34 | * MandrakeSoft S.A.
|
|---|
| 35 | * 43, rue d'Aboukir
|
|---|
| 36 | * 75002 Paris - France
|
|---|
| 37 | * http://www.linux-mandrake.com/
|
|---|
| 38 | * http://www.mandrakesoft.com/
|
|---|
| 39 | *
|
|---|
| 40 | * This library is free software; you can redistribute it and/or
|
|---|
| 41 | * modify it under the terms of the GNU Lesser General Public
|
|---|
| 42 | * License as published by the Free Software Foundation; either
|
|---|
| 43 | * version 2 of the License, or (at your option) any later version.
|
|---|
| 44 | *
|
|---|
| 45 | * This library is distributed in the hope that it will be useful,
|
|---|
| 46 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 47 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|---|
| 48 | * Lesser General Public License for more details.
|
|---|
| 49 | *
|
|---|
| 50 | * You should have received a copy of the GNU Lesser General Public
|
|---|
| 51 | * License along with this library; if not, write to the Free Software
|
|---|
| 52 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|---|
| 53 | *
|
|---|
| 54 | */
|
|---|
| 55 |
|
|---|
| 56 | /*
|
|---|
| 57 | * Oracle LGPL Disclaimer: For the avoidance of doubt, except that if any license choice
|
|---|
| 58 | * other than GPL or LGPL is available it will apply instead, Oracle elects to use only
|
|---|
| 59 | * the Lesser General Public License version 2.1 (LGPLv2) at this time for any software where
|
|---|
| 60 | * a choice of LGPL license versions is made available with the language indicating
|
|---|
| 61 | * that LGPLv2 or any later version may be used, or where a choice of which version
|
|---|
| 62 | * of the LGPL is applied is otherwise unspecified.
|
|---|
| 63 | */
|
|---|
| 64 |
|
|---|
| 65 |
|
|---|
| 66 | #include <stdint.h>
|
|---|
| 67 | #include <string.h>
|
|---|
| 68 | #include "inlines.h"
|
|---|
| 69 | #include "biosint.h"
|
|---|
| 70 | #include "ebda.h"
|
|---|
| 71 |
|
|---|
| 72 | /* Sanity check the LAN boot segment definition. */
|
|---|
| 73 | #if VBOX_LANBOOT_SEG < 0xA000
|
|---|
| 74 | #error VBOX_LANBOOT_SEG incorrect!
|
|---|
| 75 | #endif
|
|---|
| 76 |
|
|---|
| 77 | /* PnP header used with LAN boot ROMs. */
|
|---|
| 78 | typedef struct {
|
|---|
| 79 | uint32_t sig;
|
|---|
| 80 | uint8_t revision;
|
|---|
| 81 | uint8_t length;
|
|---|
| 82 | uint16_t next_s;
|
|---|
| 83 | uint8_t pad1;
|
|---|
| 84 | uint8_t checksum;
|
|---|
| 85 | uint32_t dev_id;
|
|---|
| 86 | uint16_t mfg_string;
|
|---|
| 87 | uint16_t prod_string;
|
|---|
| 88 | uint8_t base_class;
|
|---|
| 89 | uint8_t subclass;
|
|---|
| 90 | uint8_t interface;
|
|---|
| 91 | uint8_t dev_ind;
|
|---|
| 92 | uint16_t boot_code;
|
|---|
| 93 | uint16_t dv;
|
|---|
| 94 | uint16_t bev;
|
|---|
| 95 | uint16_t pad2;
|
|---|
| 96 | uint16_t sriv;
|
|---|
| 97 | } pnp_exp_t;
|
|---|
| 98 |
|
|---|
| 99 |
|
|---|
| 100 | int read_boot_sec(uint8_t bootdrv, uint16_t segment);
|
|---|
| 101 | #pragma aux read_boot_sec = \
|
|---|
| 102 | "mov ax,0201h" \
|
|---|
| 103 | "mov dh,0" \
|
|---|
| 104 | "mov cx,1" \
|
|---|
| 105 | "xor bx,bx" \
|
|---|
| 106 | "int 13h" \
|
|---|
| 107 | "mov ax,0" \
|
|---|
| 108 | "sbb ax,0" \
|
|---|
| 109 | parm [dl] [es] modify [ax bx cx dx];
|
|---|
| 110 |
|
|---|
| 111 | //--------------------------------------------------------------------------
|
|---|
| 112 | // print_boot_device
|
|---|
| 113 | // displays the boot device
|
|---|
| 114 | //--------------------------------------------------------------------------
|
|---|
| 115 |
|
|---|
| 116 | static const char drivetypes[][10]={"Floppy","Hard Disk","CD-ROM","LAN"};
|
|---|
| 117 |
|
|---|
| 118 | /// @todo pass inputs as bit flags rather than bytes?
|
|---|
| 119 | void print_boot_device(uint8_t cdboot, uint8_t lanboot, uint8_t drive)
|
|---|
| 120 | {
|
|---|
| 121 | int i;
|
|---|
| 122 |
|
|---|
| 123 | // cdboot contains 0 if lan/floppy/harddisk, 1 otherwise
|
|---|
| 124 | // lanboot contains 0 if floppy/harddisk, 1 otherwise
|
|---|
| 125 | // drive contains real/emulated boot drive
|
|---|
| 126 |
|
|---|
| 127 | if(cdboot)i=2; // CD-Rom
|
|---|
| 128 | else if(lanboot)i=3; // LAN
|
|---|
| 129 | else if((drive&0x0080)==0x00)i=0; // Floppy
|
|---|
| 130 | else if((drive&0x0080)==0x80)i=1; // Hard drive
|
|---|
| 131 | else return;
|
|---|
| 132 |
|
|---|
| 133 | BX_INFO("Booting from %s...\n",drivetypes[i]);
|
|---|
| 134 | }
|
|---|
| 135 |
|
|---|
| 136 | //--------------------------------------------------------------------------
|
|---|
| 137 | // print_boot_failure
|
|---|
| 138 | // displays the reason why boot failed
|
|---|
| 139 | //--------------------------------------------------------------------------
|
|---|
| 140 | /// @todo pass inputs as bit flags rather than bytes?
|
|---|
| 141 | void print_boot_failure(uint8_t cdboot, uint8_t lanboot, uint8_t drive,
|
|---|
| 142 | uint8_t reason, uint8_t lastdrive)
|
|---|
| 143 | {
|
|---|
| 144 | uint16_t drivenum = drive&0x7f;
|
|---|
| 145 |
|
|---|
| 146 | // cdboot: 1 if boot from cd, 0 otherwise
|
|---|
| 147 | // lanboot: 1 if boot from lan, 0 otherwise
|
|---|
| 148 | // drive : drive number
|
|---|
| 149 | // reason: 0 signature check failed, 1 read error
|
|---|
| 150 | // lastdrive: 1 boot drive is the last one in boot sequence
|
|---|
| 151 |
|
|---|
| 152 | if (cdboot)
|
|---|
| 153 | BX_INFO("Boot from %s failed\n",drivetypes[2]);
|
|---|
| 154 | else if (lanboot)
|
|---|
| 155 | BX_INFO("Boot from %s failed\n",drivetypes[3]);
|
|---|
| 156 | else if (drive & 0x80)
|
|---|
| 157 | BX_INFO("Boot from %s %d failed\n", drivetypes[1],drivenum);
|
|---|
| 158 | else
|
|---|
| 159 | BX_INFO("Boot from %s %d failed\n", drivetypes[0],drivenum);
|
|---|
| 160 |
|
|---|
| 161 | if (lastdrive==1) {
|
|---|
| 162 | if (reason==0)
|
|---|
| 163 | BX_INFO_CON("No bootable medium found!\n");
|
|---|
| 164 | else
|
|---|
| 165 | BX_INFO_CON("Could not read from the boot medium!\n");
|
|---|
| 166 | BX_INFO_CON("Please insert a bootable medium and reboot.\n");
|
|---|
| 167 | }
|
|---|
| 168 | }
|
|---|
| 169 |
|
|---|
| 170 | //--------------------------------------------------------------------------
|
|---|
| 171 | // print_cdromboot_failure
|
|---|
| 172 | // displays the reason why boot failed
|
|---|
| 173 | //--------------------------------------------------------------------------
|
|---|
| 174 | void print_cdromboot_failure(uint16_t code)
|
|---|
| 175 | {
|
|---|
| 176 | BX_INFO("CDROM boot failure code : %04x\n",code);
|
|---|
| 177 | return;
|
|---|
| 178 | }
|
|---|
| 179 |
|
|---|
| 180 | // returns bootsegment in ax, drive in bl
|
|---|
| 181 | uint32_t BIOSCALL int19_function(uint8_t bseqnr)
|
|---|
| 182 | {
|
|---|
| 183 | /// @todo common code for getting the EBDA segment
|
|---|
| 184 | uint16_t ebda_seg=read_word(0x0040,0x000E);
|
|---|
| 185 | uint16_t bootseq;
|
|---|
| 186 | uint8_t bootdrv;
|
|---|
| 187 | uint8_t bootcd;
|
|---|
| 188 | uint8_t bootlan;
|
|---|
| 189 | uint8_t bootchk;
|
|---|
| 190 | uint16_t bootseg;
|
|---|
| 191 | uint16_t status;
|
|---|
| 192 | uint8_t lastdrive=0;
|
|---|
| 193 |
|
|---|
| 194 | // if BX_ELTORITO_BOOT is not defined, old behavior
|
|---|
| 195 | // check bit 5 in CMOS reg 0x2d. load either 0x00 or 0x80 into DL
|
|---|
| 196 | // in preparation for the initial INT 13h (0=floppy A:, 0x80=C:)
|
|---|
| 197 | // 0: system boot sequence, first drive C: then A:
|
|---|
| 198 | // 1: system boot sequence, first drive A: then C:
|
|---|
| 199 | // else BX_ELTORITO_BOOT is defined
|
|---|
| 200 | // CMOS regs 0x3D and 0x38 contain the boot sequence:
|
|---|
| 201 | // CMOS reg 0x3D & 0x0f : 1st boot device
|
|---|
| 202 | // CMOS reg 0x3D & 0xf0 : 2nd boot device
|
|---|
| 203 | // CMOS reg 0x38 & 0xf0 : 3rd boot device
|
|---|
| 204 | // CMOS reg 0x3C & 0x0f : 4th boot device
|
|---|
| 205 | // boot device codes:
|
|---|
| 206 | // 0x00 : not defined
|
|---|
| 207 | // 0x01 : first floppy
|
|---|
| 208 | // 0x02 : first harddrive
|
|---|
| 209 | // 0x03 : first cdrom
|
|---|
| 210 | // 0x04 : local area network
|
|---|
| 211 | // else : boot failure
|
|---|
| 212 |
|
|---|
| 213 | // Get the boot sequence
|
|---|
| 214 | #if BX_ELTORITO_BOOT
|
|---|
| 215 | bootseq=inb_cmos(0x3d);
|
|---|
| 216 | bootseq|=((inb_cmos(0x38) & 0xf0) << 4);
|
|---|
| 217 | bootseq|=((inb_cmos(0x3c) & 0x0f) << 12);
|
|---|
| 218 | if (read_byte(ebda_seg, (uint16_t)&EbdaData->uForceBootDevice))
|
|---|
| 219 | bootseq = read_byte(ebda_seg, (uint16_t)&EbdaData->uForceBootDevice);
|
|---|
| 220 | /* Boot delay hack. */
|
|---|
| 221 | if (bseqnr == 1)
|
|---|
| 222 | delay_boot((inb_cmos(0x3c) & 0xf0) >> 4); /* Implemented in logo.c */
|
|---|
| 223 |
|
|---|
| 224 | if (bseqnr==2) bootseq >>= 4;
|
|---|
| 225 | if (bseqnr==3) bootseq >>= 8;
|
|---|
| 226 | if (bseqnr==4) bootseq >>= 12;
|
|---|
| 227 | if (bootseq<0x10) lastdrive = 1;
|
|---|
| 228 | bootdrv=0x00; bootcd=0;
|
|---|
| 229 | bootlan=0;
|
|---|
| 230 | BX_INFO("Boot : bseqnr=%d, bootseq=%x\r\n",bseqnr, bootseq);
|
|---|
| 231 |
|
|---|
| 232 | switch(bootseq & 0x0f) {
|
|---|
| 233 | case 0x01:
|
|---|
| 234 | bootdrv=0x00;
|
|---|
| 235 | bootcd=0;
|
|---|
| 236 | break;
|
|---|
| 237 | case 0x02:
|
|---|
| 238 | {
|
|---|
| 239 | // Get the Boot drive.
|
|---|
| 240 | uint8_t boot_drive = read_byte(ebda_seg, (uint16_t)&EbdaData->uForceBootDrive);
|
|---|
| 241 |
|
|---|
| 242 | bootdrv = boot_drive + 0x80;
|
|---|
| 243 | bootcd=0;
|
|---|
| 244 | break;
|
|---|
| 245 | }
|
|---|
| 246 | case 0x03:
|
|---|
| 247 | bootdrv=0x00;
|
|---|
| 248 | bootcd=1;
|
|---|
| 249 | break;
|
|---|
| 250 | case 0x04: bootlan=1; break;
|
|---|
| 251 | default: return 0x00000000;
|
|---|
| 252 | }
|
|---|
| 253 | #else
|
|---|
| 254 | bootseq=inb_cmos(0x2d);
|
|---|
| 255 |
|
|---|
| 256 | if (bseqnr==2) {
|
|---|
| 257 | bootseq ^= 0x20;
|
|---|
| 258 | lastdrive = 1;
|
|---|
| 259 | }
|
|---|
| 260 | bootdrv=0x00; bootcd=0;
|
|---|
| 261 | if((bootseq&0x20)==0) bootdrv=0x80;
|
|---|
| 262 | #endif // BX_ELTORITO_BOOT
|
|---|
| 263 |
|
|---|
| 264 | #if BX_ELTORITO_BOOT
|
|---|
| 265 | // We have to boot from cd
|
|---|
| 266 | if (bootcd != 0) {
|
|---|
| 267 | status = cdrom_boot();
|
|---|
| 268 |
|
|---|
| 269 | // If failure
|
|---|
| 270 | if ( (status & 0x00ff) !=0 ) {
|
|---|
| 271 | print_cdromboot_failure(status);
|
|---|
| 272 | print_boot_failure(bootcd, bootlan, bootdrv, 1, lastdrive);
|
|---|
| 273 | return 0x00000000;
|
|---|
| 274 | }
|
|---|
| 275 |
|
|---|
| 276 | bootseg = read_word(ebda_seg,(uint16_t)&EbdaData->cdemu.load_segment);
|
|---|
| 277 | bootdrv = (uint8_t)(status>>8);
|
|---|
| 278 | }
|
|---|
| 279 |
|
|---|
| 280 | #endif // BX_ELTORITO_BOOT
|
|---|
| 281 |
|
|---|
| 282 | // Check for boot from LAN first
|
|---|
| 283 | if (bootlan == 1) {
|
|---|
| 284 | uint8_t __far *fplan;
|
|---|
| 285 |
|
|---|
| 286 | fplan = MK_FP(VBOX_LANBOOT_SEG, 0);
|
|---|
| 287 | if (*(uint16_t __far *)fplan == 0xaa55) {
|
|---|
| 288 | pnp_exp_t __far *pnps;
|
|---|
| 289 | uint32_t manuf;
|
|---|
| 290 | void (__far *netboot_entry)(void);
|
|---|
| 291 |
|
|---|
| 292 | // This is NOT a generic PnP implementation, but an Etherboot-specific hack.
|
|---|
| 293 | pnps = (void __far *)(fplan + *(uint16_t __far *)(fplan + 0x1a));
|
|---|
| 294 | if (pnps->sig == 0x506e5024/* '$PnP' */) {
|
|---|
| 295 | // Found PnP signature
|
|---|
| 296 | manuf = *(uint32_t __far *)(fplan + pnps->mfg_string);
|
|---|
| 297 | if (manuf == 0x65687445/* 'Ethe' */) {
|
|---|
| 298 | // Found Etherboot ROM
|
|---|
| 299 | print_boot_device(bootcd, bootlan, bootdrv);
|
|---|
| 300 | netboot_entry = (void __far *)(fplan + 6);
|
|---|
| 301 | netboot_entry();
|
|---|
| 302 | }
|
|---|
| 303 | else
|
|---|
| 304 | {
|
|---|
| 305 | //Found Normal Pnp ROM
|
|---|
| 306 | print_boot_device(bootcd, bootlan, bootdrv);
|
|---|
| 307 | int_enable(); /* Disabled as we were invoked via INT instruction. */
|
|---|
| 308 | netboot_entry = (void __far *)(fplan + pnps->bev);
|
|---|
| 309 | netboot_entry();
|
|---|
| 310 | }
|
|---|
| 311 | }
|
|---|
| 312 | }
|
|---|
| 313 |
|
|---|
| 314 | // boot from LAN will not return if successful.
|
|---|
| 315 | print_boot_failure(bootcd, bootlan, bootdrv, 1, lastdrive);
|
|---|
| 316 | return 0x00000000;
|
|---|
| 317 | }
|
|---|
| 318 |
|
|---|
| 319 | // We have to boot from harddisk or floppy
|
|---|
| 320 | if (bootcd == 0 && bootlan == 0) {
|
|---|
| 321 | bootseg=0x07c0;
|
|---|
| 322 |
|
|---|
| 323 | status = read_boot_sec(bootdrv,bootseg);
|
|---|
| 324 | if (status != 0) {
|
|---|
| 325 | print_boot_failure(bootcd, bootlan, bootdrv, 1, lastdrive);
|
|---|
| 326 | return 0x00000000;
|
|---|
| 327 | }
|
|---|
| 328 | }
|
|---|
| 329 |
|
|---|
| 330 | // There is *no* requirement whatsoever for a valid floppy boot sector
|
|---|
| 331 | // to have a 55AAh signature. UNIX boot floppies typically have no such
|
|---|
| 332 | // signature. In general, it is impossible to tell a valid bootsector
|
|---|
| 333 | // from an invalid one.
|
|---|
| 334 | // NB: It is somewhat common for failed OS installs to have the
|
|---|
| 335 | // 0x55AA signature and a valid partition table but zeros in the
|
|---|
| 336 | // rest of the boot sector. We do a quick check by comparing the first
|
|---|
| 337 | // and third word of boot sector; if identical, the boot sector is
|
|---|
| 338 | // extremely unlikely to be valid.
|
|---|
| 339 | if (bootdrv != 0) bootchk = 0;
|
|---|
| 340 | else bootchk = 1; /* disable 0x55AA signature check on drive A: */
|
|---|
| 341 |
|
|---|
| 342 | #if BX_ELTORITO_BOOT
|
|---|
| 343 | // if boot from cd, no signature check
|
|---|
| 344 | if (bootcd != 0)
|
|---|
| 345 | bootchk = 1;
|
|---|
| 346 | #endif // BX_ELTORITO_BOOT
|
|---|
| 347 |
|
|---|
| 348 | if (read_word(bootseg,0) == read_word(bootseg,4)
|
|---|
| 349 | || (bootchk == 0 && read_word(bootseg,0x1fe) != 0xaa55))
|
|---|
| 350 | {
|
|---|
| 351 | print_boot_failure(bootcd, bootlan, bootdrv, 0, lastdrive);
|
|---|
| 352 | return 0x00000000;
|
|---|
| 353 | }
|
|---|
| 354 |
|
|---|
| 355 | #if BX_ELTORITO_BOOT
|
|---|
| 356 | // Print out the boot string
|
|---|
| 357 | print_boot_device(bootcd, bootlan, bootdrv);
|
|---|
| 358 | #else // BX_ELTORITO_BOOT
|
|---|
| 359 | print_boot_device(0, bootlan, bootdrv);
|
|---|
| 360 | #endif // BX_ELTORITO_BOOT
|
|---|
| 361 |
|
|---|
| 362 | // return the boot segment
|
|---|
| 363 | return (((uint32_t)bootdrv) << 16) + bootseg;
|
|---|
| 364 | }
|
|---|
| 365 |
|
|---|
