--- /dev/null
+// 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 "biosvar.h" // GET_GLOBAL
+#include "block.h" // struct drive_s
+#include "bregs.h" // struct bregs
+#include "hw/ata.h" // ATA_CMD_REQUEST_SENSE
+#include "hw/blockcmd.h" // CDB_CMD_REQUEST_SENSE
+#include "malloc.h" // free
+#include "output.h" // dprintf
+#include "std/disk.h" // DISK_RET_SUCCESS
+#include "string.h" // memset
+#include "util.h" // cdrom_prepboot
+
+// Locks for removable devices
+u8 CDRom_locks[BUILD_MAX_EXTDRIVE] VARLOW;
+
+
+/****************************************************************
+ * CD emulation
+ ****************************************************************/
+
+struct eltorito_s CDEmu VARLOW = { .size=sizeof(CDEmu) };
+struct drive_s *emulated_drive_gf VARLOW;
+struct drive_s *cdemu_drive_gf VARFSEG;
+
+static int
+cdemu_read(struct disk_op_s *op)
+{
+ struct drive_s *drive_gf = GET_LOW(emulated_drive_gf);
+ struct disk_op_s dop;
+ dop.drive_gf = drive_gf;
+ dop.command = op->command;
+ dop.lba = GET_LOW(CDEmu.ilba) + op->lba / 4;
+
+ int count = op->count;
+ op->count = 0;
+ u8 *cdbuf_fl = GET_GLOBAL(bounce_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:
+ return DISK_RET_EPARAM;
+ }
+}
+
+void
+cdrom_prepboot(void)
+{
+ if (!CONFIG_CDROM_EMU)
+ return;
+ if (!CDCount)
+ return;
+ if (create_bounce_buf() < 0)
+ return;
+
+ struct drive_s *drive = malloc_fseg(sizeof(*drive));
+ if (!drive) {
+ warn_noalloc();
+ free(drive);
+ return;
+ }
+ cdemu_drive_gf = drive;
+ memset(drive, 0, sizeof(*drive));
+ drive->type = DTYPE_CDEMU;
+ drive->blksize = DISK_SECTOR_SIZE;
+ drive->sectors = (u64)-1;
+}
+
+
+/****************************************************************
+ * CD booting
+ ****************************************************************/
+
+int
+cdrom_boot(struct drive_s *drive)
+{
+ ASSERT32FLAT();
+ struct disk_op_s dop;
+ int cdid = getDriveId(EXTTYPE_CD, drive);
+ memset(&dop, 0, sizeof(dop));
+ dop.drive_gf = drive;
+ if (!dop.drive_gf || cdid < 0)
+ return 1;
+
+ int ret = scsi_is_ready(&dop);
+ if (ret)
+ dprintf(1, "scsi_is_ready returned %d\n", ret);
+
+ // Read the Boot Record Volume Descriptor
+ u8 buffer[CDROM_SECTOR_SIZE];
+ dop.command = CMD_READ;
+ dop.lba = 0x11;
+ dop.count = 1;
+ dop.buf_fl = buffer;
+ ret = scsi_process_op(&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 = scsi_process_op(&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
+
+ // Fill in el-torito cdrom emulation fields.
+ emulated_drive_gf = drive;
+ u8 media = buffer[0x21];
+
+ u16 boot_segment = *(u16*)&buffer[0x22];
+ if (!boot_segment)
+ boot_segment = 0x07C0;
+ CDEmu.load_segment = boot_segment;
+ CDEmu.buffer_segment = 0x0000;
+
+ u16 nbsectors = *(u16*)&buffer[0x26];
+ CDEmu.sector_count = nbsectors;
+
+ lba = *(u32*)&buffer[0x28];
+ CDEmu.ilba = lba;
+
+ CDEmu.controller_index = drive->cntl_id / 2;
+ CDEmu.device_spec = drive->cntl_id % 2;
+
+ // And we read the image in memory
+ nbsectors = DIV_ROUND_UP(nbsectors, 4);
+ dop.lba = lba;
+ dop.buf_fl = MAKE_FLATPTR(boot_segment, 0);
+ while (nbsectors) {
+ int count = nbsectors;
+ if (count > 64*1024/CDROM_SECTOR_SIZE)
+ count = 64*1024/CDROM_SECTOR_SIZE;
+ dop.count = count;
+ ret = scsi_process_op(&dop);
+ if (ret)
+ return 12;
+ nbsectors -= count;
+ dop.lba += count;
+ dop.buf_fl += count*CDROM_SECTOR_SIZE;
+ }
+
+ if (media == 0) {
+ // No emulation requested - return success.
+ CDEmu.emulated_drive = 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
+ CDEmu.emulated_drive = 0x00;
+ // XXX - get and set actual floppy count.
+ set_equipment_flags(0x41, 0x41);
+
+ switch (media) {
+ case 0x01: // 1.2M floppy
+ CDEmu.chs.sptcyl = 15;
+ CDEmu.chs.cyllow = 79;
+ CDEmu.chs.heads = 1;
+ break;
+ case 0x02: // 1.44M floppy
+ CDEmu.chs.sptcyl = 18;
+ CDEmu.chs.cyllow = 79;
+ CDEmu.chs.heads = 1;
+ break;
+ case 0x03: // 2.88M floppy
+ CDEmu.chs.sptcyl = 36;
+ CDEmu.chs.cyllow = 79;
+ CDEmu.chs.heads = 1;
+ break;
+ }
+ } else {
+ // Harddrive emulation
+ CDEmu.emulated_drive = 0x80;
+ SET_BDA(hdcount, GET_BDA(hdcount) + 1);
+
+ // Peak at partition table to get chs.
+ struct mbr_s *mbr = MAKE_FLATPTR(boot_segment, 0);
+ CDEmu.chs = mbr->partitions[0].last;
+ }
+
+ // everything is ok, so from now on, the emulation is active
+ CDEmu.media = media;
+ dprintf(6, "cdemu media=%d\n", media);
+
+ return 0;
+}
Code Review / kvmfornfv.git / blobdiff