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// Support for booting from cdroms (the "El Torito" spec).
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// Copyright (C) 2008,2009 Kevin O'Connor <kevin@koconnor.net>
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// Copyright (C) 2002 MandrakeSoft S.A.
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// This file may be distributed under the terms of the GNU LGPLv3 license.
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#include "disk.h" // cdrom_13
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#include "util.h" // memset
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#include "bregs.h" // struct bregs
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#include "biosvar.h" // GET_EBDA
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#include "ata.h" // ATA_CMD_REQUEST_SENSE
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#include "blockcmd.h" // CDB_CMD_REQUEST_SENSE
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/****************************************************************
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****************************************************************/
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cdemu_read(struct disk_op_s *op)
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u16 ebda_seg = get_ebda_seg();
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struct drive_s *drive_g;
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drive_g = GLOBALFLAT2GLOBAL(GET_EBDA2(ebda_seg, cdemu.emulated_drive_gf));
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dop.drive_g = drive_g;
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dop.command = op->command;
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dop.lba = GET_EBDA2(ebda_seg, cdemu.ilba) + op->lba / 4;
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int count = op->count;
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u8 *cdbuf_far = (void*)offsetof(struct extended_bios_data_area_s, cdemu_buf);
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// Partial read of first block.
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dop.buf_fl = MAKE_FLATPTR(ebda_seg, cdbuf_far);
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int ret = process_op(&dop);
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u8 thiscount = 4 - (op->lba & 3);
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if (thiscount > count)
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memcpy_far(FLATPTR_TO_SEG(op->buf_fl)
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, (void*)FLATPTR_TO_OFFSET(op->buf_fl)
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, ebda_seg, cdbuf_far + (op->lba & 3) * 512
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op->buf_fl += thiscount * 512;
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op->count += thiscount;
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// Read n number of regular blocks.
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dop.count = count / 4;
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dop.buf_fl = op->buf_fl;
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int ret = process_op(&dop);
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op->count += dop.count * 4;
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u8 thiscount = count & ~3;
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op->buf_fl += thiscount * 512;
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dop.lba += thiscount / 4;
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// Partial read on last block.
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dop.buf_fl = MAKE_FLATPTR(ebda_seg, cdbuf_far);
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int ret = process_op(&dop);
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memcpy_far(FLATPTR_TO_SEG(op->buf_fl)
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, (void*)FLATPTR_TO_OFFSET(op->buf_fl)
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, ebda_seg, cdbuf_far, thiscount * 512);
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op->count += thiscount;
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return DISK_RET_SUCCESS;
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process_cdemu_op(struct disk_op_s *op)
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if (!CONFIG_CDROM_EMU)
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switch (op->command) {
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return cdemu_read(op);
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return DISK_RET_EWRITEPROTECT;
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return DISK_RET_SUCCESS;
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return DISK_RET_EPARAM;
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struct drive_s *cdemu_drive_gf VAR16VISIBLE;
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if (!CONFIG_CDROM_EMU)
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struct drive_s *drive_g = malloc_fseg(sizeof(*drive_g));
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cdemu_drive_gf = NULL;
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memset(drive_g, 0, sizeof(*drive_g));
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cdemu_drive_gf = drive_g;
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drive_g->type = DTYPE_CDEMU;
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drive_g->blksize = DISK_SECTOR_SIZE;
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drive_g->sectors = (u64)-1;
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#define SET_INT13ET(regs,var,val) \
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SET_FARVAR((regs)->ds, ((struct eltorito_s*)((regs)->si+0))->var, (val))
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// ElTorito - Terminate disk emu
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cdemu_134b(struct bregs *regs)
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// FIXME ElTorito Hardcoded
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u16 ebda_seg = get_ebda_seg();
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SET_INT13ET(regs, size, 0x13);
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SET_INT13ET(regs, media, GET_EBDA2(ebda_seg, cdemu.media));
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SET_INT13ET(regs, emulated_drive
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, GET_EBDA2(ebda_seg, cdemu.emulated_extdrive));
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struct drive_s *drive_gf = GET_EBDA2(ebda_seg, cdemu.emulated_drive_gf);
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cntl_id = GET_GLOBALFLAT(drive_gf->cntl_id);
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SET_INT13ET(regs, controller_index, cntl_id / 2);
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SET_INT13ET(regs, device_spec, cntl_id % 2);
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SET_INT13ET(regs, ilba, GET_EBDA2(ebda_seg, cdemu.ilba));
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SET_INT13ET(regs, buffer_segment, GET_EBDA2(ebda_seg, cdemu.buffer_segment));
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SET_INT13ET(regs, load_segment, GET_EBDA2(ebda_seg, cdemu.load_segment));
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SET_INT13ET(regs, sector_count, GET_EBDA2(ebda_seg, cdemu.sector_count));
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SET_INT13ET(regs, cylinders, GET_EBDA2(ebda_seg, cdemu.lchs.cylinders));
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SET_INT13ET(regs, sectors, GET_EBDA2(ebda_seg, cdemu.lchs.spt));
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SET_INT13ET(regs, heads, GET_EBDA2(ebda_seg, cdemu.lchs.heads));
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// If we have to terminate emulation
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if (regs->al == 0x00) {
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// FIXME ElTorito Various. Should be handled accordingly to spec
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SET_EBDA2(ebda_seg, cdemu.active, 0x00); // bye bye
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// XXX - update floppy/hd count.
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disk_ret(regs, DISK_RET_SUCCESS);
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/****************************************************************
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****************************************************************/
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atapi_is_ready(struct disk_op_s *op)
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dprintf(6, "atapi_is_ready (drive=%p)\n", op->drive_g);
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/* Retry READ CAPACITY for 5 seconds unless MEDIUM NOT PRESENT is
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* reported by the device. If the device reports "IN PROGRESS",
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* 30 seconds is added. */
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struct cdbres_read_capacity info;
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u64 end = calc_future_tsc(5000);
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if (check_time(end)) {
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dprintf(1, "read capacity failed\n");
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int ret = cdb_read_capacity(op, &info);
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struct cdbres_request_sense sense;
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ret = cdb_get_sense(op, &sense);
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if (sense.asc == 0x3a) { /* MEDIUM NOT PRESENT */
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dprintf(1, "Device reports MEDIUM NOT PRESENT\n");
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if (sense.asc == 0x04 && sense.ascq == 0x01 && !in_progress) {
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/* IN PROGRESS OF BECOMING READY */
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printf("Waiting for device to detect medium... ");
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/* Allow 30 seconds more */
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end = calc_future_tsc(30000);
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u32 blksize = ntohl(info.blksize), sectors = ntohl(info.sectors);
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if (blksize != GET_GLOBAL(op->drive_g->blksize)) {
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printf("Unsupported sector size %u\n", blksize);
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dprintf(6, "sectors=%u\n", sectors);
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printf("%dMB medium detected\n", sectors>>(20-11));
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struct disk_op_s dop;
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memset(&dop, 0, sizeof(dop));
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dop.drive_g = getDrive(EXTTYPE_CD, cdid);
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int ret = atapi_is_ready(&dop);
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dprintf(1, "atapi_is_ready returned %d\n", ret);
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// Read the Boot Record Volume Descriptor
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dop.buf_fl = MAKE_FLATPTR(GET_SEG(SS), buffer);
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ret = cdb_read(&dop);
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if (strcmp((char*)&buffer[1], "CD001\001EL TORITO SPECIFICATION") != 0)
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// ok, now we calculate the Boot catalog address
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u32 lba = *(u32*)&buffer[0x47];
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// And we read the Boot Catalog
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ret = cdb_read(&dop);
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if (buffer[0x00] != 0x01)
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if (buffer[0x01] != 0x00)
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return 9; // Platform
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if (buffer[0x1E] != 0x55)
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if (buffer[0x1F] != 0xAA)
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// Initial/Default Entry
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if (buffer[0x20] != 0x88)
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return 11; // Bootable
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u16 ebda_seg = get_ebda_seg();
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u8 media = buffer[0x21];
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SET_EBDA2(ebda_seg, cdemu.media, media);
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SET_EBDA2(ebda_seg, cdemu.emulated_drive_gf, dop.drive_g);
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u16 boot_segment = *(u16*)&buffer[0x22];
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boot_segment = 0x07C0;
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SET_EBDA2(ebda_seg, cdemu.load_segment, boot_segment);
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SET_EBDA2(ebda_seg, cdemu.buffer_segment, 0x0000);
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u16 nbsectors = *(u16*)&buffer[0x26];
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SET_EBDA2(ebda_seg, cdemu.sector_count, nbsectors);
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lba = *(u32*)&buffer[0x28];
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SET_EBDA2(ebda_seg, cdemu.ilba, lba);
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// And we read the image in memory
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dop.count = DIV_ROUND_UP(nbsectors, 4);
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dop.buf_fl = MAKE_FLATPTR(boot_segment, 0);
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ret = cdb_read(&dop);
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// No emulation requested - return success.
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SET_EBDA2(ebda_seg, cdemu.emulated_extdrive, EXTSTART_CD + cdid);
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// Emulation of a floppy/harddisk requested
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if (! CONFIG_CDROM_EMU || !cdemu_drive_gf)
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// Set emulated drive id and increase bios installed hardware
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SET_EBDA2(ebda_seg, cdemu.emulated_extdrive, 0x00);
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// XXX - get and set actual floppy count.
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SETBITS_BDA(equipment_list_flags, 0x41);
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case 0x01: // 1.2M floppy
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SET_EBDA2(ebda_seg, cdemu.lchs.spt, 15);
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SET_EBDA2(ebda_seg, cdemu.lchs.cylinders, 80);
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SET_EBDA2(ebda_seg, cdemu.lchs.heads, 2);
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case 0x02: // 1.44M floppy
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SET_EBDA2(ebda_seg, cdemu.lchs.spt, 18);
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SET_EBDA2(ebda_seg, cdemu.lchs.cylinders, 80);
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SET_EBDA2(ebda_seg, cdemu.lchs.heads, 2);
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case 0x03: // 2.88M floppy
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SET_EBDA2(ebda_seg, cdemu.lchs.spt, 36);
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SET_EBDA2(ebda_seg, cdemu.lchs.cylinders, 80);
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SET_EBDA2(ebda_seg, cdemu.lchs.heads, 2);
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// Harddrive emulation
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SET_EBDA2(ebda_seg, cdemu.emulated_extdrive, 0x80);
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SET_BDA(hdcount, GET_BDA(hdcount) + 1);
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// Peak at partition table to get chs.
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struct mbr_s *mbr = (void*)0;
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u8 sptcyl = GET_FARVAR(boot_segment, mbr->partitions[0].last.sptcyl);
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u8 cyllow = GET_FARVAR(boot_segment, mbr->partitions[0].last.cyllow);
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u8 heads = GET_FARVAR(boot_segment, mbr->partitions[0].last.heads);
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SET_EBDA2(ebda_seg, cdemu.lchs.spt, sptcyl & 0x3f);
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SET_EBDA2(ebda_seg, cdemu.lchs.cylinders
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, ((sptcyl<<2)&0x300) + cyllow + 1);
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SET_EBDA2(ebda_seg, cdemu.lchs.heads, heads + 1);
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// everything is ok, so from now on, the emulation is active
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SET_EBDA2(ebda_seg, cdemu.active, 0x01);
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dprintf(6, "cdemu media=%d\n", media);