blob: fc81ed60d24f23f9209e9f3831f1bb728daa0b66 [file] [log] [blame]
// Code to load disk image and start system boot.
//
// Copyright (C) 2008 Kevin O'Connor <kevin@koconnor.net>
// Copyright (C) 2002 MandrakeSoft S.A.
//
// This file may be distributed under the terms of the GNU LGPLv3 license.
#include "util.h" // irq_enable
#include "biosvar.h" // GET_EBDA
#include "config.h" // CONFIG_*
#include "disk.h" // cdrom_boot
#include "bregs.h" // struct bregs
#include "boot.h" // struct ipl_s
#include "cmos.h" // inb_cmos
struct ipl_s IPL;
/****************************************************************
* IPL handlers
****************************************************************/
void
boot_setup()
{
if (! CONFIG_BOOT)
return;
dprintf(3, "init boot device ordering\n");
memset(&IPL, 0, sizeof(IPL));
// Floppy drive
struct ipl_entry_s *ie = &IPL.table[0];
ie->type = IPL_TYPE_FLOPPY;
ie->description = "Floppy";
ie++;
// First HDD
ie->type = IPL_TYPE_HARDDISK;
ie->description = "Hard Disk";
ie++;
// CDROM
if (CONFIG_CDROM_BOOT) {
ie->type = IPL_TYPE_CDROM;
ie->description = "CD-Rom";
ie++;
}
IPL.count = ie - IPL.table;
SET_EBDA(boot_sequence, 0xffff);
if (CONFIG_COREBOOT) {
// XXX - hardcode defaults for coreboot.
IPL.bootorder = 0x00000231;
IPL.checkfloppysig = 1;
} else {
// On emulators, get boot order from nvram.
IPL.bootorder = (inb_cmos(CMOS_BIOS_BOOTFLAG2)
| ((inb_cmos(CMOS_BIOS_BOOTFLAG1) & 0xf0) << 4));
if (!(inb_cmos(CMOS_BIOS_BOOTFLAG1) & 1))
IPL.checkfloppysig = 1;
}
}
// Add a BEV vector for a given pnp compatible option rom.
void
add_bev(u16 seg, u16 bev, u16 desc)
{
// Found a device that thinks it can boot the system. Record
// its BEV and product name string.
if (! CONFIG_BOOT)
return;
if (IPL.count >= ARRAY_SIZE(IPL.table))
return;
struct ipl_entry_s *ie = &IPL.table[IPL.count];
ie->type = IPL_TYPE_BEV;
ie->vector = (seg << 16) | bev;
if (desc)
ie->description = MAKE_FLATPTR(seg, desc);
IPL.count++;
}
/****************************************************************
* Boot menu
****************************************************************/
void
interactive_bootmenu()
{
if (! CONFIG_BOOTMENU)
return;
while (get_keystroke(0) >= 0)
;
printf("Press F12 for boot menu.\n\n");
int scan_code = get_keystroke(2500);
if (scan_code != 0x86)
/* not F12 */
return;
while (get_keystroke(0) >= 0)
;
printf("Select boot device:\n\n");
int count = IPL.count;
int i;
for (i = 0; i < count; i++) {
struct ipl_entry_s *ie = &IPL.table[i];
char desc[33];
printf("%d. %s\n", i+1
, strtcpy(desc, ie->description, ARRAY_SIZE(desc)));
}
for (;;) {
scan_code = get_keystroke(1000);
if (scan_code == 0x01)
// ESC
break;
if (scan_code >= 0 && scan_code <= count + 1) {
// Add user choice to the boot order.
u16 choice = scan_code - 1;
u32 bootorder = IPL.bootorder;
IPL.bootorder = (bootorder << 4) | choice;
break;
}
}
printf("\n");
}
/****************************************************************
* Boot code (int 18/19)
****************************************************************/
static void
call_boot_entry(u16 bootseg, u16 bootip, u8 bootdrv)
{
dprintf(1, "Booting from %x:%x\n", bootseg, bootip);
struct bregs br;
memset(&br, 0, sizeof(br));
br.ip = bootip;
br.cs = bootseg;
// Set the magic number in ax and the boot drive in dl.
br.dl = bootdrv;
br.ax = 0xaa55;
call16(&br);
}
// Boot from a disk (either floppy or harddrive)
static void
boot_disk(u8 bootdrv, int checksig)
{
u16 bootseg = 0x07c0;
// Read sector
struct bregs br;
memset(&br, 0, sizeof(br));
br.dl = bootdrv;
br.es = bootseg;
br.ah = 2;
br.al = 1;
br.cl = 1;
call16_int(0x13, &br);
if (br.flags & F_CF) {
printf("Boot failed: could not read the boot disk\n\n");
return;
}
if (checksig) {
struct mbr_s *mbr = (void*)0;
if (GET_FARVAR(bootseg, mbr->signature) != MBR_SIGNATURE) {
printf("Boot failed: not a bootable disk\n\n");
return;
}
}
/* Canonicalize bootseg:bootip */
u16 bootip = (bootseg & 0x0fff) << 4;
bootseg &= 0xf000;
call_boot_entry(bootseg, bootip, bootdrv);
}
// Boot from a CD-ROM
static void
boot_cdrom()
{
if (! CONFIG_CDROM_BOOT)
return;
int status = cdrom_boot();
if (status) {
printf("Boot failed: Could not read from CDROM (code %04x)\n", status);
return;
}
u16 ebda_seg = get_ebda_seg();
u8 bootdrv = GET_EBDA2(ebda_seg, cdemu.emulated_drive);
u16 bootseg = GET_EBDA2(ebda_seg, cdemu.load_segment);
/* Canonicalize bootseg:bootip */
u16 bootip = (bootseg & 0x0fff) << 4;
bootseg &= 0xf000;
call_boot_entry(bootseg, bootip, bootdrv);
}
static void
do_boot(u16 seq_nr)
{
if (! CONFIG_BOOT)
panic("Boot support not compiled in.\n");
u32 bootdev = IPL.bootorder;
bootdev >>= 4 * seq_nr;
bootdev &= 0xf;
if (bootdev == 0)
panic("No bootable device.\n");
/* Translate bootdev to an IPL table offset by subtracting 1 */
bootdev -= 1;
if (bootdev >= IPL.count) {
dprintf(1, "Invalid boot device (0x%x)\n", bootdev);
goto fail;
}
/* Do the loading, and set up vector as a far pointer to the boot
* address, and bootdrv as the boot drive */
struct ipl_entry_s *ie = &IPL.table[bootdev];
char desc[33];
printf("Booting from %s...\n"
, strtcpy(desc, ie->description, ARRAY_SIZE(desc)));
switch(ie->type) {
case IPL_TYPE_FLOPPY:
boot_disk(0x00, IPL.checkfloppysig);
break;
case IPL_TYPE_HARDDISK:
boot_disk(0x80, 1);
break;
case IPL_TYPE_CDROM:
boot_cdrom();
break;
case IPL_TYPE_BEV:
call_boot_entry(ie->vector >> 16, ie->vector & 0xffff, 0);
break;
}
// Boot failed: invoke the boot recovery function
struct bregs br;
fail:
memset(&br, 0, sizeof(br));
call16_int(0x18, &br);
}
// Boot Failure recovery: try the next device.
void VISIBLE32
handle_18()
{
debug_serial_setup();
debug_enter(NULL, DEBUG_HDL_18);
u16 ebda_seg = get_ebda_seg();
u16 seq = GET_EBDA2(ebda_seg, boot_sequence) + 1;
SET_EBDA2(ebda_seg, boot_sequence, seq);
do_boot(seq);
}
// INT 19h Boot Load Service Entry Point
void VISIBLE32
handle_19()
{
debug_serial_setup();
debug_enter(NULL, DEBUG_HDL_19);
SET_EBDA(boot_sequence, 0);
do_boot(0);
}
// Ughh - some older gcc compilers have a bug which causes VISIBLE32
// functions to not be exported as global variables.
asm(".global handle_18, handle_19");