1 // Support for booting from cdroms (the "El Torito" spec).
3 // Copyright (C) 2008,2009 Kevin O'Connor <kevin@koconnor.net>
4 // Copyright (C) 2002 MandrakeSoft S.A.
6 // This file may be distributed under the terms of the GNU LGPLv3 license.
8 #include "disk.h" // cdrom_13
9 #include "util.h" // memset
10 #include "bregs.h" // struct bregs
11 #include "biosvar.h" // GET_EBDA
12 #include "ata.h" // ATA_CMD_REQUEST_SENSE
13 #include "blockcmd.h" // CDB_CMD_REQUEST_SENSE
16 /****************************************************************
18 ****************************************************************/
20 struct drive_s *cdemu_drive_gf VAR16VISIBLE;
23 cdemu_read(struct disk_op_s *op)
25 u16 ebda_seg = get_ebda_seg();
26 struct drive_s *drive_g;
27 drive_g = GLOBALFLAT2GLOBAL(GET_EBDA2(ebda_seg, cdemu.emulated_drive_gf));
29 dop.drive_g = drive_g;
30 dop.command = op->command;
31 dop.lba = GET_EBDA2(ebda_seg, cdemu.ilba) + op->lba / 4;
33 int count = op->count;
35 u8 *cdbuf_fl = GET_GLOBAL(bounce_buf_fl);
38 // Partial read of first block.
40 dop.buf_fl = cdbuf_fl;
41 int ret = process_op(&dop);
44 u8 thiscount = 4 - (op->lba & 3);
45 if (thiscount > count)
48 memcpy_fl(op->buf_fl, cdbuf_fl + (op->lba & 3) * 512, thiscount * 512);
49 op->buf_fl += thiscount * 512;
50 op->count += thiscount;
55 // Read n number of regular blocks.
56 dop.count = count / 4;
57 dop.buf_fl = op->buf_fl;
58 int ret = process_op(&dop);
59 op->count += dop.count * 4;
62 u8 thiscount = count & ~3;
64 op->buf_fl += thiscount * 512;
65 dop.lba += thiscount / 4;
69 // Partial read on last block.
71 dop.buf_fl = cdbuf_fl;
72 int ret = process_op(&dop);
76 memcpy_fl(op->buf_fl, cdbuf_fl, thiscount * 512);
77 op->count += thiscount;
80 return DISK_RET_SUCCESS;
84 process_cdemu_op(struct disk_op_s *op)
86 if (!CONFIG_CDROM_EMU)
89 switch (op->command) {
91 return cdemu_read(op);
94 return DISK_RET_EWRITEPROTECT;
99 return DISK_RET_SUCCESS;
102 return DISK_RET_EPARAM;
109 if (!CONFIG_CDROM_EMU)
113 if (bounce_buf_init() < 0)
116 struct drive_s *drive_g = malloc_fseg(sizeof(*drive_g));
122 cdemu_drive_gf = drive_g;
123 memset(drive_g, 0, sizeof(*drive_g));
124 drive_g->type = DTYPE_CDEMU;
125 drive_g->blksize = DISK_SECTOR_SIZE;
126 drive_g->sectors = (u64)-1;
144 #define SET_INT13ET(regs,var,val) \
145 SET_FARVAR((regs)->ds, ((struct eltorito_s*)((regs)->si+0))->var, (val))
147 // ElTorito - Terminate disk emu
149 cdemu_134b(struct bregs *regs)
151 // FIXME ElTorito Hardcoded
152 u16 ebda_seg = get_ebda_seg();
153 SET_INT13ET(regs, size, 0x13);
154 SET_INT13ET(regs, media, GET_EBDA2(ebda_seg, cdemu.media));
155 SET_INT13ET(regs, emulated_drive
156 , GET_EBDA2(ebda_seg, cdemu.emulated_extdrive));
157 struct drive_s *drive_gf = GET_EBDA2(ebda_seg, cdemu.emulated_drive_gf);
160 cntl_id = GET_GLOBALFLAT(drive_gf->cntl_id);
161 SET_INT13ET(regs, controller_index, cntl_id / 2);
162 SET_INT13ET(regs, device_spec, cntl_id % 2);
163 SET_INT13ET(regs, ilba, GET_EBDA2(ebda_seg, cdemu.ilba));
164 SET_INT13ET(regs, buffer_segment, GET_EBDA2(ebda_seg, cdemu.buffer_segment));
165 SET_INT13ET(regs, load_segment, GET_EBDA2(ebda_seg, cdemu.load_segment));
166 SET_INT13ET(regs, sector_count, GET_EBDA2(ebda_seg, cdemu.sector_count));
167 SET_INT13ET(regs, cylinders, GET_EBDA2(ebda_seg, cdemu.lchs.cylinders));
168 SET_INT13ET(regs, sectors, GET_EBDA2(ebda_seg, cdemu.lchs.spt));
169 SET_INT13ET(regs, heads, GET_EBDA2(ebda_seg, cdemu.lchs.heads));
171 // If we have to terminate emulation
172 if (regs->al == 0x00) {
173 // FIXME ElTorito Various. Should be handled accordingly to spec
174 SET_EBDA2(ebda_seg, cdemu.active, 0x00); // bye bye
176 // XXX - update floppy/hd count.
179 disk_ret(regs, DISK_RET_SUCCESS);
183 /****************************************************************
185 ****************************************************************/
188 cdrom_boot(struct drive_s *drive_g)
190 struct disk_op_s dop;
191 int cdid = getDriveId(EXTTYPE_CD, drive_g);
192 memset(&dop, 0, sizeof(dop));
193 dop.drive_g = drive_g;
194 if (!dop.drive_g || cdid < 0)
197 int ret = scsi_is_ready(&dop);
199 dprintf(1, "scsi_is_ready returned %d\n", ret);
201 // Read the Boot Record Volume Descriptor
205 dop.buf_fl = MAKE_FLATPTR(GET_SEG(SS), buffer);
206 ret = cdb_read(&dop);
213 if (strcmp((char*)&buffer[1], "CD001\001EL TORITO SPECIFICATION") != 0)
216 // ok, now we calculate the Boot catalog address
217 u32 lba = *(u32*)&buffer[0x47];
219 // And we read the Boot Catalog
222 ret = cdb_read(&dop);
227 if (buffer[0x00] != 0x01)
229 if (buffer[0x01] != 0x00)
230 return 9; // Platform
231 if (buffer[0x1E] != 0x55)
233 if (buffer[0x1F] != 0xAA)
236 // Initial/Default Entry
237 if (buffer[0x20] != 0x88)
238 return 11; // Bootable
240 u16 ebda_seg = get_ebda_seg();
241 u8 media = buffer[0x21];
242 SET_EBDA2(ebda_seg, cdemu.media, media);
244 SET_EBDA2(ebda_seg, cdemu.emulated_drive_gf, dop.drive_g);
246 u16 boot_segment = *(u16*)&buffer[0x22];
248 boot_segment = 0x07C0;
249 SET_EBDA2(ebda_seg, cdemu.load_segment, boot_segment);
250 SET_EBDA2(ebda_seg, cdemu.buffer_segment, 0x0000);
252 u16 nbsectors = *(u16*)&buffer[0x26];
253 SET_EBDA2(ebda_seg, cdemu.sector_count, nbsectors);
255 lba = *(u32*)&buffer[0x28];
256 SET_EBDA2(ebda_seg, cdemu.ilba, lba);
258 // And we read the image in memory
260 dop.count = DIV_ROUND_UP(nbsectors, 4);
261 dop.buf_fl = MAKE_FLATPTR(boot_segment, 0);
262 ret = cdb_read(&dop);
267 // No emulation requested - return success.
268 SET_EBDA2(ebda_seg, cdemu.emulated_extdrive, EXTSTART_CD + cdid);
272 // Emulation of a floppy/harddisk requested
273 if (! CONFIG_CDROM_EMU || !cdemu_drive_gf)
276 // Set emulated drive id and increase bios installed hardware
280 SET_EBDA2(ebda_seg, cdemu.emulated_extdrive, 0x00);
281 // XXX - get and set actual floppy count.
282 SETBITS_BDA(equipment_list_flags, 0x41);
285 case 0x01: // 1.2M floppy
286 SET_EBDA2(ebda_seg, cdemu.lchs.spt, 15);
287 SET_EBDA2(ebda_seg, cdemu.lchs.cylinders, 80);
288 SET_EBDA2(ebda_seg, cdemu.lchs.heads, 2);
290 case 0x02: // 1.44M floppy
291 SET_EBDA2(ebda_seg, cdemu.lchs.spt, 18);
292 SET_EBDA2(ebda_seg, cdemu.lchs.cylinders, 80);
293 SET_EBDA2(ebda_seg, cdemu.lchs.heads, 2);
295 case 0x03: // 2.88M floppy
296 SET_EBDA2(ebda_seg, cdemu.lchs.spt, 36);
297 SET_EBDA2(ebda_seg, cdemu.lchs.cylinders, 80);
298 SET_EBDA2(ebda_seg, cdemu.lchs.heads, 2);
302 // Harddrive emulation
303 SET_EBDA2(ebda_seg, cdemu.emulated_extdrive, 0x80);
304 SET_BDA(hdcount, GET_BDA(hdcount) + 1);
306 // Peak at partition table to get chs.
307 struct mbr_s *mbr = (void*)0;
308 u8 sptcyl = GET_FARVAR(boot_segment, mbr->partitions[0].last.sptcyl);
309 u8 cyllow = GET_FARVAR(boot_segment, mbr->partitions[0].last.cyllow);
310 u8 heads = GET_FARVAR(boot_segment, mbr->partitions[0].last.heads);
312 SET_EBDA2(ebda_seg, cdemu.lchs.spt, sptcyl & 0x3f);
313 SET_EBDA2(ebda_seg, cdemu.lchs.cylinders
314 , ((sptcyl<<2)&0x300) + cyllow + 1);
315 SET_EBDA2(ebda_seg, cdemu.lchs.heads, heads + 1);
318 // everything is ok, so from now on, the emulation is active
319 SET_EBDA2(ebda_seg, cdemu.active, 0x01);
320 dprintf(6, "cdemu media=%d\n", media);