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// Support for booting from cdroms (the "El Torito" spec).
//
// Copyright (C) 2008,2009 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 "disk.h" // cdrom_13
#include "util.h" // memset
#include "bregs.h" // struct bregs
#include "biosvar.h" // GET_EBDA
#include "ata.h" // ATA_CMD_REQUEST_SENSE
#include "blockcmd.h" // CDB_CMD_REQUEST_SENSE
/****************************************************************
* CD emulation
****************************************************************/
struct drive_s *cdemu_drive_gf VAR16VISIBLE;
u8 *cdemu_buf_fl VAR16VISIBLE;
static int
cdemu_read(struct disk_op_s *op)
{
u16 ebda_seg = get_ebda_seg();
struct drive_s *drive_g;
drive_g = GLOBALFLAT2GLOBAL(GET_EBDA2(ebda_seg, cdemu.emulated_drive_gf));
struct disk_op_s dop;
dop.drive_g = drive_g;
dop.command = op->command;
dop.lba = GET_EBDA2(ebda_seg, cdemu.ilba) + op->lba / 4;
int count = op->count;
op->count = 0;
u8 *cdbuf_fl = GET_GLOBAL(cdemu_buf_fl);
if (op->lba & 3) {
// Partial read of first block.
dop.count = 1;
dop.buf_fl = cdbuf_fl;
int ret = process_op(&dop);
if (ret)
return ret;
u8 thiscount = 4 - (op->lba & 3);
if (thiscount > count)
thiscount = count;
count -= thiscount;
memcpy_fl(op->buf_fl, cdbuf_fl + (op->lba & 3) * 512, thiscount * 512);
op->buf_fl += thiscount * 512;
op->count += thiscount;
dop.lba++;
}
if (count > 3) {
// Read n number of regular blocks.
dop.count = count / 4;
dop.buf_fl = op->buf_fl;
int ret = process_op(&dop);
op->count += dop.count * 4;
if (ret)
return ret;
u8 thiscount = count & ~3;
count &= 3;
op->buf_fl += thiscount * 512;
dop.lba += thiscount / 4;
}
if (count) {
// Partial read on last block.
dop.count = 1;
dop.buf_fl = cdbuf_fl;
int ret = process_op(&dop);
if (ret)
return ret;
u8 thiscount = count;
memcpy_fl(op->buf_fl, cdbuf_fl, thiscount * 512);
op->count += thiscount;
}
return DISK_RET_SUCCESS;
}
int
process_cdemu_op(struct disk_op_s *op)
{
if (!CONFIG_CDROM_EMU)
return 0;
switch (op->command) {
case CMD_READ:
return cdemu_read(op);
case CMD_WRITE:
case CMD_FORMAT:
return DISK_RET_EWRITEPROTECT;
case CMD_VERIFY:
case CMD_RESET:
case CMD_SEEK:
case CMD_ISREADY:
return DISK_RET_SUCCESS;
default:
op->count = 0;
return DISK_RET_EPARAM;
}
}
void
cdemu_setup(void)
{
if (!CONFIG_CDROM_EMU)
return;
if (!CDCount)
return;
struct drive_s *drive_g = malloc_fseg(sizeof(*drive_g));
u8 *buf = malloc_low(CDROM_SECTOR_SIZE);
if (!drive_g || !buf) {
warn_noalloc();
free(drive_g);
free(buf);
return;
}
cdemu_drive_gf = drive_g;
cdemu_buf_fl = buf;
memset(drive_g, 0, sizeof(*drive_g));
drive_g->type = DTYPE_CDEMU;
drive_g->blksize = DISK_SECTOR_SIZE;
drive_g->sectors = (u64)-1;
}
struct eltorito_s {
u8 size;
u8 media;
u8 emulated_drive;
u8 controller_index;
u32 ilba;
u16 device_spec;
u16 buffer_segment;
u16 load_segment;
u16 sector_count;
u8 cylinders;
u8 sectors;
u8 heads;
};
#define SET_INT13ET(regs,var,val) \
SET_FARVAR((regs)->ds, ((struct eltorito_s*)((regs)->si+0))->var, (val))
// ElTorito - Terminate disk emu
void
cdemu_134b(struct bregs *regs)
{
// FIXME ElTorito Hardcoded
u16 ebda_seg = get_ebda_seg();
SET_INT13ET(regs, size, 0x13);
SET_INT13ET(regs, media, GET_EBDA2(ebda_seg, cdemu.media));
SET_INT13ET(regs, emulated_drive
, GET_EBDA2(ebda_seg, cdemu.emulated_extdrive));
struct drive_s *drive_gf = GET_EBDA2(ebda_seg, cdemu.emulated_drive_gf);
u8 cntl_id = 0;
if (drive_gf)
cntl_id = GET_GLOBALFLAT(drive_gf->cntl_id);
SET_INT13ET(regs, controller_index, cntl_id / 2);
SET_INT13ET(regs, device_spec, cntl_id % 2);
SET_INT13ET(regs, ilba, GET_EBDA2(ebda_seg, cdemu.ilba));
SET_INT13ET(regs, buffer_segment, GET_EBDA2(ebda_seg, cdemu.buffer_segment));
SET_INT13ET(regs, load_segment, GET_EBDA2(ebda_seg, cdemu.load_segment));
SET_INT13ET(regs, sector_count, GET_EBDA2(ebda_seg, cdemu.sector_count));
SET_INT13ET(regs, cylinders, GET_EBDA2(ebda_seg, cdemu.lchs.cylinders));
SET_INT13ET(regs, sectors, GET_EBDA2(ebda_seg, cdemu.lchs.spt));
SET_INT13ET(regs, heads, GET_EBDA2(ebda_seg, cdemu.lchs.heads));
// If we have to terminate emulation
if (regs->al == 0x00) {
// FIXME ElTorito Various. Should be handled accordingly to spec
SET_EBDA2(ebda_seg, cdemu.active, 0x00); // bye bye
// XXX - update floppy/hd count.
}
disk_ret(regs, DISK_RET_SUCCESS);
}
/****************************************************************
* CD booting
****************************************************************/
static int
atapi_is_ready(struct disk_op_s *op)
{
dprintf(6, "atapi_is_ready (drive=%p)\n", op->drive_g);
/* Retry READ CAPACITY for 5 seconds unless MEDIUM NOT PRESENT is
* reported by the device. If the device reports "IN PROGRESS",
* 30 seconds is added. */
struct cdbres_read_capacity info;
int in_progress = 0;
u64 end = calc_future_tsc(5000);
for (;;) {
if (check_tsc(end)) {
dprintf(1, "read capacity failed\n");
return -1;
}
int ret = cdb_read_capacity(op, &info);
if (!ret)
// Success
break;
struct cdbres_request_sense sense;
ret = cdb_get_sense(op, &sense);
if (ret)
// Error - retry.
continue;
// Sense succeeded.
if (sense.asc == 0x3a) { /* MEDIUM NOT PRESENT */
dprintf(1, "Device reports MEDIUM NOT PRESENT\n");
return -1;
}
if (sense.asc == 0x04 && sense.ascq == 0x01 && !in_progress) {
/* IN PROGRESS OF BECOMING READY */
printf("Waiting for device to detect medium... ");
/* Allow 30 seconds more */
end = calc_future_tsc(30000);
in_progress = 1;
}
}
u32 blksize = ntohl(info.blksize), sectors = ntohl(info.sectors);
if (blksize != GET_GLOBAL(op->drive_g->blksize)) {
printf("Unsupported sector size %u\n", blksize);
return -1;
}
dprintf(6, "sectors=%u\n", sectors);
printf("%dMB medium detected\n", sectors>>(20-11));
return 0;
}
int
cdrom_boot(struct drive_s *drive_g)
{
struct disk_op_s dop;
int cdid = getDriveId(EXTTYPE_CD, drive_g);
memset(&dop, 0, sizeof(dop));
dop.drive_g = drive_g;
if (!dop.drive_g || cdid < 0)
return 1;
int ret = atapi_is_ready(&dop);
if (ret)
dprintf(1, "atapi_is_ready returned %d\n", ret);
// Read the Boot Record Volume Descriptor
u8 buffer[2048];
dop.lba = 0x11;
dop.count = 1;
dop.buf_fl = MAKE_FLATPTR(GET_SEG(SS), buffer);
ret = cdb_read(&dop);
if (ret)
return 3;
// Validity checks
if (buffer[0])
return 4;
if (strcmp((char*)&buffer[1], "CD001\001EL TORITO SPECIFICATION") != 0)
return 5;
// ok, now we calculate the Boot catalog address
u32 lba = *(u32*)&buffer[0x47];
// And we read the Boot Catalog
dop.lba = lba;
dop.count = 1;
ret = cdb_read(&dop);
if (ret)
return 7;
// Validation entry
if (buffer[0x00] != 0x01)
return 8; // Header
if (buffer[0x01] != 0x00)
return 9; // Platform
if (buffer[0x1E] != 0x55)
return 10; // key 1
if (buffer[0x1F] != 0xAA)
return 10; // key 2
// Initial/Default Entry
if (buffer[0x20] != 0x88)
return 11; // Bootable
u16 ebda_seg = get_ebda_seg();
u8 media = buffer[0x21];
SET_EBDA2(ebda_seg, cdemu.media, media);
SET_EBDA2(ebda_seg, cdemu.emulated_drive_gf, dop.drive_g);
u16 boot_segment = *(u16*)&buffer[0x22];
if (!boot_segment)
boot_segment = 0x07C0;
SET_EBDA2(ebda_seg, cdemu.load_segment, boot_segment);
SET_EBDA2(ebda_seg, cdemu.buffer_segment, 0x0000);
u16 nbsectors = *(u16*)&buffer[0x26];
SET_EBDA2(ebda_seg, cdemu.sector_count, nbsectors);
lba = *(u32*)&buffer[0x28];
SET_EBDA2(ebda_seg, cdemu.ilba, lba);
// And we read the image in memory
dop.lba = lba;
dop.count = DIV_ROUND_UP(nbsectors, 4);
dop.buf_fl = MAKE_FLATPTR(boot_segment, 0);
ret = cdb_read(&dop);
if (ret)
return 12;
if (media == 0) {
// No emulation requested - return success.
SET_EBDA2(ebda_seg, cdemu.emulated_extdrive, EXTSTART_CD + cdid);
return 0;
}
// Emulation of a floppy/harddisk requested
if (! CONFIG_CDROM_EMU || !cdemu_drive_gf)
return 13;
// Set emulated drive id and increase bios installed hardware
// number of devices
if (media < 4) {
// Floppy emulation
SET_EBDA2(ebda_seg, cdemu.emulated_extdrive, 0x00);
// XXX - get and set actual floppy count.
SETBITS_BDA(equipment_list_flags, 0x41);
switch (media) {
case 0x01: // 1.2M floppy
SET_EBDA2(ebda_seg, cdemu.lchs.spt, 15);
SET_EBDA2(ebda_seg, cdemu.lchs.cylinders, 80);
SET_EBDA2(ebda_seg, cdemu.lchs.heads, 2);
break;
case 0x02: // 1.44M floppy
SET_EBDA2(ebda_seg, cdemu.lchs.spt, 18);
SET_EBDA2(ebda_seg, cdemu.lchs.cylinders, 80);
SET_EBDA2(ebda_seg, cdemu.lchs.heads, 2);
break;
case 0x03: // 2.88M floppy
SET_EBDA2(ebda_seg, cdemu.lchs.spt, 36);
SET_EBDA2(ebda_seg, cdemu.lchs.cylinders, 80);
SET_EBDA2(ebda_seg, cdemu.lchs.heads, 2);
break;
}
} else {
// Harddrive emulation
SET_EBDA2(ebda_seg, cdemu.emulated_extdrive, 0x80);
SET_BDA(hdcount, GET_BDA(hdcount) + 1);
// Peak at partition table to get chs.
struct mbr_s *mbr = (void*)0;
u8 sptcyl = GET_FARVAR(boot_segment, mbr->partitions[0].last.sptcyl);
u8 cyllow = GET_FARVAR(boot_segment, mbr->partitions[0].last.cyllow);
u8 heads = GET_FARVAR(boot_segment, mbr->partitions[0].last.heads);
SET_EBDA2(ebda_seg, cdemu.lchs.spt, sptcyl & 0x3f);
SET_EBDA2(ebda_seg, cdemu.lchs.cylinders
, ((sptcyl<<2)&0x300) + cyllow + 1);
SET_EBDA2(ebda_seg, cdemu.lchs.heads, heads + 1);
}
// everything is ok, so from now on, the emulation is active
SET_EBDA2(ebda_seg, cdemu.active, 0x01);
dprintf(6, "cdemu media=%d\n", media);
return 0;
}