xref: /openbmc/qemu/hw/block/fdc.c (revision 87c9b5e0)
1 /*
2  * QEMU Floppy disk emulator (Intel 82078)
3  *
4  * Copyright (c) 2003, 2007 Jocelyn Mayer
5  * Copyright (c) 2008 Hervé Poussineau
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 /*
26  * The controller is used in Sun4m systems in a slightly different
27  * way. There are changes in DOR register and DMA is not available.
28  */
29 
30 #include "qemu/osdep.h"
31 #include "hw/hw.h"
32 #include "hw/block/fdc.h"
33 #include "qemu/error-report.h"
34 #include "qemu/timer.h"
35 #include "hw/isa/isa.h"
36 #include "hw/sysbus.h"
37 #include "sysemu/block-backend.h"
38 #include "sysemu/blockdev.h"
39 #include "sysemu/sysemu.h"
40 #include "qemu/log.h"
41 
42 /********************************************************/
43 /* debug Floppy devices */
44 //#define DEBUG_FLOPPY
45 
46 #ifdef DEBUG_FLOPPY
47 #define FLOPPY_DPRINTF(fmt, ...)                                \
48     do { printf("FLOPPY: " fmt , ## __VA_ARGS__); } while (0)
49 #else
50 #define FLOPPY_DPRINTF(fmt, ...)
51 #endif
52 
53 /********************************************************/
54 /* Floppy drive emulation                               */
55 
56 typedef enum FDriveRate {
57     FDRIVE_RATE_500K = 0x00,  /* 500 Kbps */
58     FDRIVE_RATE_300K = 0x01,  /* 300 Kbps */
59     FDRIVE_RATE_250K = 0x02,  /* 250 Kbps */
60     FDRIVE_RATE_1M   = 0x03,  /*   1 Mbps */
61 } FDriveRate;
62 
63 typedef enum FDriveSize {
64     FDRIVE_SIZE_UNKNOWN,
65     FDRIVE_SIZE_350,
66     FDRIVE_SIZE_525,
67 } FDriveSize;
68 
69 typedef struct FDFormat {
70     FloppyDriveType drive;
71     uint8_t last_sect;
72     uint8_t max_track;
73     uint8_t max_head;
74     FDriveRate rate;
75 } FDFormat;
76 
77 /* In many cases, the total sector size of a format is enough to uniquely
78  * identify it. However, there are some total sector collisions between
79  * formats of different physical size, and these are noted below by
80  * highlighting the total sector size for entries with collisions. */
81 static const FDFormat fd_formats[] = {
82     /* First entry is default format */
83     /* 1.44 MB 3"1/2 floppy disks */
84     { FLOPPY_DRIVE_TYPE_144, 18, 80, 1, FDRIVE_RATE_500K, }, /* 3.5" 2880 */
85     { FLOPPY_DRIVE_TYPE_144, 20, 80, 1, FDRIVE_RATE_500K, }, /* 3.5" 3200 */
86     { FLOPPY_DRIVE_TYPE_144, 21, 80, 1, FDRIVE_RATE_500K, },
87     { FLOPPY_DRIVE_TYPE_144, 21, 82, 1, FDRIVE_RATE_500K, },
88     { FLOPPY_DRIVE_TYPE_144, 21, 83, 1, FDRIVE_RATE_500K, },
89     { FLOPPY_DRIVE_TYPE_144, 22, 80, 1, FDRIVE_RATE_500K, },
90     { FLOPPY_DRIVE_TYPE_144, 23, 80, 1, FDRIVE_RATE_500K, },
91     { FLOPPY_DRIVE_TYPE_144, 24, 80, 1, FDRIVE_RATE_500K, },
92     /* 2.88 MB 3"1/2 floppy disks */
93     { FLOPPY_DRIVE_TYPE_288, 36, 80, 1, FDRIVE_RATE_1M, },
94     { FLOPPY_DRIVE_TYPE_288, 39, 80, 1, FDRIVE_RATE_1M, },
95     { FLOPPY_DRIVE_TYPE_288, 40, 80, 1, FDRIVE_RATE_1M, },
96     { FLOPPY_DRIVE_TYPE_288, 44, 80, 1, FDRIVE_RATE_1M, },
97     { FLOPPY_DRIVE_TYPE_288, 48, 80, 1, FDRIVE_RATE_1M, },
98     /* 720 kB 3"1/2 floppy disks */
99     { FLOPPY_DRIVE_TYPE_144,  9, 80, 1, FDRIVE_RATE_250K, }, /* 3.5" 1440 */
100     { FLOPPY_DRIVE_TYPE_144, 10, 80, 1, FDRIVE_RATE_250K, },
101     { FLOPPY_DRIVE_TYPE_144, 10, 82, 1, FDRIVE_RATE_250K, },
102     { FLOPPY_DRIVE_TYPE_144, 10, 83, 1, FDRIVE_RATE_250K, },
103     { FLOPPY_DRIVE_TYPE_144, 13, 80, 1, FDRIVE_RATE_250K, },
104     { FLOPPY_DRIVE_TYPE_144, 14, 80, 1, FDRIVE_RATE_250K, },
105     /* 1.2 MB 5"1/4 floppy disks */
106     { FLOPPY_DRIVE_TYPE_120, 15, 80, 1, FDRIVE_RATE_500K, },
107     { FLOPPY_DRIVE_TYPE_120, 18, 80, 1, FDRIVE_RATE_500K, }, /* 5.25" 2880 */
108     { FLOPPY_DRIVE_TYPE_120, 18, 82, 1, FDRIVE_RATE_500K, },
109     { FLOPPY_DRIVE_TYPE_120, 18, 83, 1, FDRIVE_RATE_500K, },
110     { FLOPPY_DRIVE_TYPE_120, 20, 80, 1, FDRIVE_RATE_500K, }, /* 5.25" 3200 */
111     /* 720 kB 5"1/4 floppy disks */
112     { FLOPPY_DRIVE_TYPE_120,  9, 80, 1, FDRIVE_RATE_250K, }, /* 5.25" 1440 */
113     { FLOPPY_DRIVE_TYPE_120, 11, 80, 1, FDRIVE_RATE_250K, },
114     /* 360 kB 5"1/4 floppy disks */
115     { FLOPPY_DRIVE_TYPE_120,  9, 40, 1, FDRIVE_RATE_300K, }, /* 5.25" 720 */
116     { FLOPPY_DRIVE_TYPE_120,  9, 40, 0, FDRIVE_RATE_300K, },
117     { FLOPPY_DRIVE_TYPE_120, 10, 41, 1, FDRIVE_RATE_300K, },
118     { FLOPPY_DRIVE_TYPE_120, 10, 42, 1, FDRIVE_RATE_300K, },
119     /* 320 kB 5"1/4 floppy disks */
120     { FLOPPY_DRIVE_TYPE_120,  8, 40, 1, FDRIVE_RATE_250K, },
121     { FLOPPY_DRIVE_TYPE_120,  8, 40, 0, FDRIVE_RATE_250K, },
122     /* 360 kB must match 5"1/4 better than 3"1/2... */
123     { FLOPPY_DRIVE_TYPE_144,  9, 80, 0, FDRIVE_RATE_250K, }, /* 3.5" 720 */
124     /* end */
125     { FLOPPY_DRIVE_TYPE_NONE, -1, -1, 0, 0, },
126 };
127 
128 static FDriveSize drive_size(FloppyDriveType drive)
129 {
130     switch (drive) {
131     case FLOPPY_DRIVE_TYPE_120:
132         return FDRIVE_SIZE_525;
133     case FLOPPY_DRIVE_TYPE_144:
134     case FLOPPY_DRIVE_TYPE_288:
135         return FDRIVE_SIZE_350;
136     default:
137         return FDRIVE_SIZE_UNKNOWN;
138     }
139 }
140 
141 #define GET_CUR_DRV(fdctrl) ((fdctrl)->cur_drv)
142 #define SET_CUR_DRV(fdctrl, drive) ((fdctrl)->cur_drv = (drive))
143 
144 /* Will always be a fixed parameter for us */
145 #define FD_SECTOR_LEN          512
146 #define FD_SECTOR_SC           2   /* Sector size code */
147 #define FD_RESET_SENSEI_COUNT  4   /* Number of sense interrupts on RESET */
148 
149 typedef struct FDCtrl FDCtrl;
150 
151 /* Floppy disk drive emulation */
152 typedef enum FDiskFlags {
153     FDISK_DBL_SIDES  = 0x01,
154 } FDiskFlags;
155 
156 typedef struct FDrive {
157     FDCtrl *fdctrl;
158     BlockBackend *blk;
159     /* Drive status */
160     FloppyDriveType drive;    /* CMOS drive type        */
161     uint8_t perpendicular;    /* 2.88 MB access mode    */
162     /* Position */
163     uint8_t head;
164     uint8_t track;
165     uint8_t sect;
166     /* Media */
167     FloppyDriveType disk;     /* Current disk type      */
168     FDiskFlags flags;
169     uint8_t last_sect;        /* Nb sector per track    */
170     uint8_t max_track;        /* Nb of tracks           */
171     uint16_t bps;             /* Bytes per sector       */
172     uint8_t ro;               /* Is read-only           */
173     uint8_t media_changed;    /* Is media changed       */
174     uint8_t media_rate;       /* Data rate of medium    */
175 
176     bool media_validated;     /* Have we validated the media? */
177 } FDrive;
178 
179 
180 static FloppyDriveType get_fallback_drive_type(FDrive *drv);
181 
182 /* Hack: FD_SEEK is expected to work on empty drives. However, QEMU
183  * currently goes through some pains to keep seeks within the bounds
184  * established by last_sect and max_track. Correcting this is difficult,
185  * as refactoring FDC code tends to expose nasty bugs in the Linux kernel.
186  *
187  * For now: allow empty drives to have large bounds so we can seek around,
188  * with the understanding that when a diskette is inserted, the bounds will
189  * properly tighten to match the geometry of that inserted medium.
190  */
191 static void fd_empty_seek_hack(FDrive *drv)
192 {
193     drv->last_sect = 0xFF;
194     drv->max_track = 0xFF;
195 }
196 
197 static void fd_init(FDrive *drv)
198 {
199     /* Drive */
200     drv->perpendicular = 0;
201     /* Disk */
202     drv->disk = FLOPPY_DRIVE_TYPE_NONE;
203     drv->last_sect = 0;
204     drv->max_track = 0;
205     drv->ro = true;
206     drv->media_changed = 1;
207 }
208 
209 #define NUM_SIDES(drv) ((drv)->flags & FDISK_DBL_SIDES ? 2 : 1)
210 
211 static int fd_sector_calc(uint8_t head, uint8_t track, uint8_t sect,
212                           uint8_t last_sect, uint8_t num_sides)
213 {
214     return (((track * num_sides) + head) * last_sect) + sect - 1;
215 }
216 
217 /* Returns current position, in sectors, for given drive */
218 static int fd_sector(FDrive *drv)
219 {
220     return fd_sector_calc(drv->head, drv->track, drv->sect, drv->last_sect,
221                           NUM_SIDES(drv));
222 }
223 
224 /* Seek to a new position:
225  * returns 0 if already on right track
226  * returns 1 if track changed
227  * returns 2 if track is invalid
228  * returns 3 if sector is invalid
229  * returns 4 if seek is disabled
230  */
231 static int fd_seek(FDrive *drv, uint8_t head, uint8_t track, uint8_t sect,
232                    int enable_seek)
233 {
234     uint32_t sector;
235     int ret;
236 
237     if (track > drv->max_track ||
238         (head != 0 && (drv->flags & FDISK_DBL_SIDES) == 0)) {
239         FLOPPY_DPRINTF("try to read %d %02x %02x (max=%d %d %02x %02x)\n",
240                        head, track, sect, 1,
241                        (drv->flags & FDISK_DBL_SIDES) == 0 ? 0 : 1,
242                        drv->max_track, drv->last_sect);
243         return 2;
244     }
245     if (sect > drv->last_sect) {
246         FLOPPY_DPRINTF("try to read %d %02x %02x (max=%d %d %02x %02x)\n",
247                        head, track, sect, 1,
248                        (drv->flags & FDISK_DBL_SIDES) == 0 ? 0 : 1,
249                        drv->max_track, drv->last_sect);
250         return 3;
251     }
252     sector = fd_sector_calc(head, track, sect, drv->last_sect, NUM_SIDES(drv));
253     ret = 0;
254     if (sector != fd_sector(drv)) {
255 #if 0
256         if (!enable_seek) {
257             FLOPPY_DPRINTF("error: no implicit seek %d %02x %02x"
258                            " (max=%d %02x %02x)\n",
259                            head, track, sect, 1, drv->max_track,
260                            drv->last_sect);
261             return 4;
262         }
263 #endif
264         drv->head = head;
265         if (drv->track != track) {
266             if (drv->blk != NULL && blk_is_inserted(drv->blk)) {
267                 drv->media_changed = 0;
268             }
269             ret = 1;
270         }
271         drv->track = track;
272         drv->sect = sect;
273     }
274 
275     if (drv->blk == NULL || !blk_is_inserted(drv->blk)) {
276         ret = 2;
277     }
278 
279     return ret;
280 }
281 
282 /* Set drive back to track 0 */
283 static void fd_recalibrate(FDrive *drv)
284 {
285     FLOPPY_DPRINTF("recalibrate\n");
286     fd_seek(drv, 0, 0, 1, 1);
287 }
288 
289 /**
290  * Determine geometry based on inserted diskette.
291  * Will not operate on an empty drive.
292  *
293  * @return: 0 on success, -1 if the drive is empty.
294  */
295 static int pick_geometry(FDrive *drv)
296 {
297     BlockBackend *blk = drv->blk;
298     const FDFormat *parse;
299     uint64_t nb_sectors, size;
300     int i;
301     int match, size_match, type_match;
302     bool magic = drv->drive == FLOPPY_DRIVE_TYPE_AUTO;
303 
304     /* We can only pick a geometry if we have a diskette. */
305     if (!drv->blk || !blk_is_inserted(drv->blk) ||
306         drv->drive == FLOPPY_DRIVE_TYPE_NONE)
307     {
308         return -1;
309     }
310 
311     /* We need to determine the likely geometry of the inserted medium.
312      * In order of preference, we look for:
313      * (1) The same drive type and number of sectors,
314      * (2) The same diskette size and number of sectors,
315      * (3) The same drive type.
316      *
317      * In all cases, matches that occur higher in the drive table will take
318      * precedence over matches that occur later in the table.
319      */
320     blk_get_geometry(blk, &nb_sectors);
321     match = size_match = type_match = -1;
322     for (i = 0; ; i++) {
323         parse = &fd_formats[i];
324         if (parse->drive == FLOPPY_DRIVE_TYPE_NONE) {
325             break;
326         }
327         size = (parse->max_head + 1) * parse->max_track * parse->last_sect;
328         if (nb_sectors == size) {
329             if (magic || parse->drive == drv->drive) {
330                 /* (1) perfect match -- nb_sectors and drive type */
331                 goto out;
332             } else if (drive_size(parse->drive) == drive_size(drv->drive)) {
333                 /* (2) size match -- nb_sectors and physical medium size */
334                 match = (match == -1) ? i : match;
335             } else {
336                 /* This is suspicious -- Did the user misconfigure? */
337                 size_match = (size_match == -1) ? i : size_match;
338             }
339         } else if (type_match == -1) {
340             if ((parse->drive == drv->drive) ||
341                 (magic && (parse->drive == get_fallback_drive_type(drv)))) {
342                 /* (3) type match -- nb_sectors mismatch, but matches the type
343                  *     specified explicitly by the user, or matches the fallback
344                  *     default type when using the drive autodetect mechanism */
345                 type_match = i;
346             }
347         }
348     }
349 
350     /* No exact match found */
351     if (match == -1) {
352         if (size_match != -1) {
353             parse = &fd_formats[size_match];
354             FLOPPY_DPRINTF("User requested floppy drive type '%s', "
355                            "but inserted medium appears to be a "
356                            "%d sector '%s' type\n",
357                            FloppyDriveType_lookup[drv->drive],
358                            nb_sectors,
359                            FloppyDriveType_lookup[parse->drive]);
360         }
361         match = type_match;
362     }
363 
364     /* No match of any kind found -- fd_format is misconfigured, abort. */
365     if (match == -1) {
366         error_setg(&error_abort, "No candidate geometries present in table "
367                    " for floppy drive type '%s'",
368                    FloppyDriveType_lookup[drv->drive]);
369     }
370 
371     parse = &(fd_formats[match]);
372 
373  out:
374     if (parse->max_head == 0) {
375         drv->flags &= ~FDISK_DBL_SIDES;
376     } else {
377         drv->flags |= FDISK_DBL_SIDES;
378     }
379     drv->max_track = parse->max_track;
380     drv->last_sect = parse->last_sect;
381     drv->disk = parse->drive;
382     drv->media_rate = parse->rate;
383     return 0;
384 }
385 
386 static void pick_drive_type(FDrive *drv)
387 {
388     if (drv->drive != FLOPPY_DRIVE_TYPE_AUTO) {
389         return;
390     }
391 
392     if (pick_geometry(drv) == 0) {
393         drv->drive = drv->disk;
394     } else {
395         drv->drive = get_fallback_drive_type(drv);
396     }
397 
398     g_assert(drv->drive != FLOPPY_DRIVE_TYPE_AUTO);
399 }
400 
401 /* Revalidate a disk drive after a disk change */
402 static void fd_revalidate(FDrive *drv)
403 {
404     int rc;
405 
406     FLOPPY_DPRINTF("revalidate\n");
407     if (drv->blk != NULL) {
408         drv->ro = blk_is_read_only(drv->blk);
409         if (!blk_is_inserted(drv->blk)) {
410             FLOPPY_DPRINTF("No disk in drive\n");
411             drv->disk = FLOPPY_DRIVE_TYPE_NONE;
412             fd_empty_seek_hack(drv);
413         } else if (!drv->media_validated) {
414             rc = pick_geometry(drv);
415             if (rc) {
416                 FLOPPY_DPRINTF("Could not validate floppy drive media");
417             } else {
418                 drv->media_validated = true;
419                 FLOPPY_DPRINTF("Floppy disk (%d h %d t %d s) %s\n",
420                                (drv->flags & FDISK_DBL_SIDES) ? 2 : 1,
421                                drv->max_track, drv->last_sect,
422                                drv->ro ? "ro" : "rw");
423             }
424         }
425     } else {
426         FLOPPY_DPRINTF("No drive connected\n");
427         drv->last_sect = 0;
428         drv->max_track = 0;
429         drv->flags &= ~FDISK_DBL_SIDES;
430         drv->drive = FLOPPY_DRIVE_TYPE_NONE;
431         drv->disk = FLOPPY_DRIVE_TYPE_NONE;
432     }
433 }
434 
435 /********************************************************/
436 /* Intel 82078 floppy disk controller emulation          */
437 
438 static void fdctrl_reset(FDCtrl *fdctrl, int do_irq);
439 static void fdctrl_to_command_phase(FDCtrl *fdctrl);
440 static int fdctrl_transfer_handler (void *opaque, int nchan,
441                                     int dma_pos, int dma_len);
442 static void fdctrl_raise_irq(FDCtrl *fdctrl);
443 static FDrive *get_cur_drv(FDCtrl *fdctrl);
444 
445 static uint32_t fdctrl_read_statusA(FDCtrl *fdctrl);
446 static uint32_t fdctrl_read_statusB(FDCtrl *fdctrl);
447 static uint32_t fdctrl_read_dor(FDCtrl *fdctrl);
448 static void fdctrl_write_dor(FDCtrl *fdctrl, uint32_t value);
449 static uint32_t fdctrl_read_tape(FDCtrl *fdctrl);
450 static void fdctrl_write_tape(FDCtrl *fdctrl, uint32_t value);
451 static uint32_t fdctrl_read_main_status(FDCtrl *fdctrl);
452 static void fdctrl_write_rate(FDCtrl *fdctrl, uint32_t value);
453 static uint32_t fdctrl_read_data(FDCtrl *fdctrl);
454 static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t value);
455 static uint32_t fdctrl_read_dir(FDCtrl *fdctrl);
456 static void fdctrl_write_ccr(FDCtrl *fdctrl, uint32_t value);
457 
458 enum {
459     FD_DIR_WRITE   = 0,
460     FD_DIR_READ    = 1,
461     FD_DIR_SCANE   = 2,
462     FD_DIR_SCANL   = 3,
463     FD_DIR_SCANH   = 4,
464     FD_DIR_VERIFY  = 5,
465 };
466 
467 enum {
468     FD_STATE_MULTI  = 0x01,	/* multi track flag */
469     FD_STATE_FORMAT = 0x02,	/* format flag */
470 };
471 
472 enum {
473     FD_REG_SRA = 0x00,
474     FD_REG_SRB = 0x01,
475     FD_REG_DOR = 0x02,
476     FD_REG_TDR = 0x03,
477     FD_REG_MSR = 0x04,
478     FD_REG_DSR = 0x04,
479     FD_REG_FIFO = 0x05,
480     FD_REG_DIR = 0x07,
481     FD_REG_CCR = 0x07,
482 };
483 
484 enum {
485     FD_CMD_READ_TRACK = 0x02,
486     FD_CMD_SPECIFY = 0x03,
487     FD_CMD_SENSE_DRIVE_STATUS = 0x04,
488     FD_CMD_WRITE = 0x05,
489     FD_CMD_READ = 0x06,
490     FD_CMD_RECALIBRATE = 0x07,
491     FD_CMD_SENSE_INTERRUPT_STATUS = 0x08,
492     FD_CMD_WRITE_DELETED = 0x09,
493     FD_CMD_READ_ID = 0x0a,
494     FD_CMD_READ_DELETED = 0x0c,
495     FD_CMD_FORMAT_TRACK = 0x0d,
496     FD_CMD_DUMPREG = 0x0e,
497     FD_CMD_SEEK = 0x0f,
498     FD_CMD_VERSION = 0x10,
499     FD_CMD_SCAN_EQUAL = 0x11,
500     FD_CMD_PERPENDICULAR_MODE = 0x12,
501     FD_CMD_CONFIGURE = 0x13,
502     FD_CMD_LOCK = 0x14,
503     FD_CMD_VERIFY = 0x16,
504     FD_CMD_POWERDOWN_MODE = 0x17,
505     FD_CMD_PART_ID = 0x18,
506     FD_CMD_SCAN_LOW_OR_EQUAL = 0x19,
507     FD_CMD_SCAN_HIGH_OR_EQUAL = 0x1d,
508     FD_CMD_SAVE = 0x2e,
509     FD_CMD_OPTION = 0x33,
510     FD_CMD_RESTORE = 0x4e,
511     FD_CMD_DRIVE_SPECIFICATION_COMMAND = 0x8e,
512     FD_CMD_RELATIVE_SEEK_OUT = 0x8f,
513     FD_CMD_FORMAT_AND_WRITE = 0xcd,
514     FD_CMD_RELATIVE_SEEK_IN = 0xcf,
515 };
516 
517 enum {
518     FD_CONFIG_PRETRK = 0xff, /* Pre-compensation set to track 0 */
519     FD_CONFIG_FIFOTHR = 0x0f, /* FIFO threshold set to 1 byte */
520     FD_CONFIG_POLL  = 0x10, /* Poll enabled */
521     FD_CONFIG_EFIFO = 0x20, /* FIFO disabled */
522     FD_CONFIG_EIS   = 0x40, /* No implied seeks */
523 };
524 
525 enum {
526     FD_SR0_DS0      = 0x01,
527     FD_SR0_DS1      = 0x02,
528     FD_SR0_HEAD     = 0x04,
529     FD_SR0_EQPMT    = 0x10,
530     FD_SR0_SEEK     = 0x20,
531     FD_SR0_ABNTERM  = 0x40,
532     FD_SR0_INVCMD   = 0x80,
533     FD_SR0_RDYCHG   = 0xc0,
534 };
535 
536 enum {
537     FD_SR1_MA       = 0x01, /* Missing address mark */
538     FD_SR1_NW       = 0x02, /* Not writable */
539     FD_SR1_EC       = 0x80, /* End of cylinder */
540 };
541 
542 enum {
543     FD_SR2_SNS      = 0x04, /* Scan not satisfied */
544     FD_SR2_SEH      = 0x08, /* Scan equal hit */
545 };
546 
547 enum {
548     FD_SRA_DIR      = 0x01,
549     FD_SRA_nWP      = 0x02,
550     FD_SRA_nINDX    = 0x04,
551     FD_SRA_HDSEL    = 0x08,
552     FD_SRA_nTRK0    = 0x10,
553     FD_SRA_STEP     = 0x20,
554     FD_SRA_nDRV2    = 0x40,
555     FD_SRA_INTPEND  = 0x80,
556 };
557 
558 enum {
559     FD_SRB_MTR0     = 0x01,
560     FD_SRB_MTR1     = 0x02,
561     FD_SRB_WGATE    = 0x04,
562     FD_SRB_RDATA    = 0x08,
563     FD_SRB_WDATA    = 0x10,
564     FD_SRB_DR0      = 0x20,
565 };
566 
567 enum {
568 #if MAX_FD == 4
569     FD_DOR_SELMASK  = 0x03,
570 #else
571     FD_DOR_SELMASK  = 0x01,
572 #endif
573     FD_DOR_nRESET   = 0x04,
574     FD_DOR_DMAEN    = 0x08,
575     FD_DOR_MOTEN0   = 0x10,
576     FD_DOR_MOTEN1   = 0x20,
577     FD_DOR_MOTEN2   = 0x40,
578     FD_DOR_MOTEN3   = 0x80,
579 };
580 
581 enum {
582 #if MAX_FD == 4
583     FD_TDR_BOOTSEL  = 0x0c,
584 #else
585     FD_TDR_BOOTSEL  = 0x04,
586 #endif
587 };
588 
589 enum {
590     FD_DSR_DRATEMASK= 0x03,
591     FD_DSR_PWRDOWN  = 0x40,
592     FD_DSR_SWRESET  = 0x80,
593 };
594 
595 enum {
596     FD_MSR_DRV0BUSY = 0x01,
597     FD_MSR_DRV1BUSY = 0x02,
598     FD_MSR_DRV2BUSY = 0x04,
599     FD_MSR_DRV3BUSY = 0x08,
600     FD_MSR_CMDBUSY  = 0x10,
601     FD_MSR_NONDMA   = 0x20,
602     FD_MSR_DIO      = 0x40,
603     FD_MSR_RQM      = 0x80,
604 };
605 
606 enum {
607     FD_DIR_DSKCHG   = 0x80,
608 };
609 
610 /*
611  * See chapter 5.0 "Controller phases" of the spec:
612  *
613  * Command phase:
614  * The host writes a command and its parameters into the FIFO. The command
615  * phase is completed when all parameters for the command have been supplied,
616  * and execution phase is entered.
617  *
618  * Execution phase:
619  * Data transfers, either DMA or non-DMA. For non-DMA transfers, the FIFO
620  * contains the payload now, otherwise it's unused. When all bytes of the
621  * required data have been transferred, the state is switched to either result
622  * phase (if the command produces status bytes) or directly back into the
623  * command phase for the next command.
624  *
625  * Result phase:
626  * The host reads out the FIFO, which contains one or more result bytes now.
627  */
628 enum {
629     /* Only for migration: reconstruct phase from registers like qemu 2.3 */
630     FD_PHASE_RECONSTRUCT    = 0,
631 
632     FD_PHASE_COMMAND        = 1,
633     FD_PHASE_EXECUTION      = 2,
634     FD_PHASE_RESULT         = 3,
635 };
636 
637 #define FD_MULTI_TRACK(state) ((state) & FD_STATE_MULTI)
638 #define FD_FORMAT_CMD(state) ((state) & FD_STATE_FORMAT)
639 
640 struct FDCtrl {
641     MemoryRegion iomem;
642     qemu_irq irq;
643     /* Controller state */
644     QEMUTimer *result_timer;
645     int dma_chann;
646     uint8_t phase;
647     IsaDma *dma;
648     /* Controller's identification */
649     uint8_t version;
650     /* HW */
651     uint8_t sra;
652     uint8_t srb;
653     uint8_t dor;
654     uint8_t dor_vmstate; /* only used as temp during vmstate */
655     uint8_t tdr;
656     uint8_t dsr;
657     uint8_t msr;
658     uint8_t cur_drv;
659     uint8_t status0;
660     uint8_t status1;
661     uint8_t status2;
662     /* Command FIFO */
663     uint8_t *fifo;
664     int32_t fifo_size;
665     uint32_t data_pos;
666     uint32_t data_len;
667     uint8_t data_state;
668     uint8_t data_dir;
669     uint8_t eot; /* last wanted sector */
670     /* States kept only to be returned back */
671     /* precompensation */
672     uint8_t precomp_trk;
673     uint8_t config;
674     uint8_t lock;
675     /* Power down config (also with status regB access mode */
676     uint8_t pwrd;
677     /* Floppy drives */
678     uint8_t num_floppies;
679     FDrive drives[MAX_FD];
680     int reset_sensei;
681     uint32_t check_media_rate;
682     FloppyDriveType fallback; /* type=auto failure fallback */
683     /* Timers state */
684     uint8_t timer0;
685     uint8_t timer1;
686 };
687 
688 static FloppyDriveType get_fallback_drive_type(FDrive *drv)
689 {
690     return drv->fdctrl->fallback;
691 }
692 
693 #define TYPE_SYSBUS_FDC "base-sysbus-fdc"
694 #define SYSBUS_FDC(obj) OBJECT_CHECK(FDCtrlSysBus, (obj), TYPE_SYSBUS_FDC)
695 
696 typedef struct FDCtrlSysBus {
697     /*< private >*/
698     SysBusDevice parent_obj;
699     /*< public >*/
700 
701     struct FDCtrl state;
702 } FDCtrlSysBus;
703 
704 #define ISA_FDC(obj) OBJECT_CHECK(FDCtrlISABus, (obj), TYPE_ISA_FDC)
705 
706 typedef struct FDCtrlISABus {
707     ISADevice parent_obj;
708 
709     uint32_t iobase;
710     uint32_t irq;
711     uint32_t dma;
712     struct FDCtrl state;
713     int32_t bootindexA;
714     int32_t bootindexB;
715 } FDCtrlISABus;
716 
717 static uint32_t fdctrl_read (void *opaque, uint32_t reg)
718 {
719     FDCtrl *fdctrl = opaque;
720     uint32_t retval;
721 
722     reg &= 7;
723     switch (reg) {
724     case FD_REG_SRA:
725         retval = fdctrl_read_statusA(fdctrl);
726         break;
727     case FD_REG_SRB:
728         retval = fdctrl_read_statusB(fdctrl);
729         break;
730     case FD_REG_DOR:
731         retval = fdctrl_read_dor(fdctrl);
732         break;
733     case FD_REG_TDR:
734         retval = fdctrl_read_tape(fdctrl);
735         break;
736     case FD_REG_MSR:
737         retval = fdctrl_read_main_status(fdctrl);
738         break;
739     case FD_REG_FIFO:
740         retval = fdctrl_read_data(fdctrl);
741         break;
742     case FD_REG_DIR:
743         retval = fdctrl_read_dir(fdctrl);
744         break;
745     default:
746         retval = (uint32_t)(-1);
747         break;
748     }
749     FLOPPY_DPRINTF("read reg%d: 0x%02x\n", reg & 7, retval);
750 
751     return retval;
752 }
753 
754 static void fdctrl_write (void *opaque, uint32_t reg, uint32_t value)
755 {
756     FDCtrl *fdctrl = opaque;
757 
758     FLOPPY_DPRINTF("write reg%d: 0x%02x\n", reg & 7, value);
759 
760     reg &= 7;
761     switch (reg) {
762     case FD_REG_DOR:
763         fdctrl_write_dor(fdctrl, value);
764         break;
765     case FD_REG_TDR:
766         fdctrl_write_tape(fdctrl, value);
767         break;
768     case FD_REG_DSR:
769         fdctrl_write_rate(fdctrl, value);
770         break;
771     case FD_REG_FIFO:
772         fdctrl_write_data(fdctrl, value);
773         break;
774     case FD_REG_CCR:
775         fdctrl_write_ccr(fdctrl, value);
776         break;
777     default:
778         break;
779     }
780 }
781 
782 static uint64_t fdctrl_read_mem (void *opaque, hwaddr reg,
783                                  unsigned ize)
784 {
785     return fdctrl_read(opaque, (uint32_t)reg);
786 }
787 
788 static void fdctrl_write_mem (void *opaque, hwaddr reg,
789                               uint64_t value, unsigned size)
790 {
791     fdctrl_write(opaque, (uint32_t)reg, value);
792 }
793 
794 static const MemoryRegionOps fdctrl_mem_ops = {
795     .read = fdctrl_read_mem,
796     .write = fdctrl_write_mem,
797     .endianness = DEVICE_NATIVE_ENDIAN,
798 };
799 
800 static const MemoryRegionOps fdctrl_mem_strict_ops = {
801     .read = fdctrl_read_mem,
802     .write = fdctrl_write_mem,
803     .endianness = DEVICE_NATIVE_ENDIAN,
804     .valid = {
805         .min_access_size = 1,
806         .max_access_size = 1,
807     },
808 };
809 
810 static bool fdrive_media_changed_needed(void *opaque)
811 {
812     FDrive *drive = opaque;
813 
814     return (drive->blk != NULL && drive->media_changed != 1);
815 }
816 
817 static const VMStateDescription vmstate_fdrive_media_changed = {
818     .name = "fdrive/media_changed",
819     .version_id = 1,
820     .minimum_version_id = 1,
821     .needed = fdrive_media_changed_needed,
822     .fields = (VMStateField[]) {
823         VMSTATE_UINT8(media_changed, FDrive),
824         VMSTATE_END_OF_LIST()
825     }
826 };
827 
828 static bool fdrive_media_rate_needed(void *opaque)
829 {
830     FDrive *drive = opaque;
831 
832     return drive->fdctrl->check_media_rate;
833 }
834 
835 static const VMStateDescription vmstate_fdrive_media_rate = {
836     .name = "fdrive/media_rate",
837     .version_id = 1,
838     .minimum_version_id = 1,
839     .needed = fdrive_media_rate_needed,
840     .fields = (VMStateField[]) {
841         VMSTATE_UINT8(media_rate, FDrive),
842         VMSTATE_END_OF_LIST()
843     }
844 };
845 
846 static bool fdrive_perpendicular_needed(void *opaque)
847 {
848     FDrive *drive = opaque;
849 
850     return drive->perpendicular != 0;
851 }
852 
853 static const VMStateDescription vmstate_fdrive_perpendicular = {
854     .name = "fdrive/perpendicular",
855     .version_id = 1,
856     .minimum_version_id = 1,
857     .needed = fdrive_perpendicular_needed,
858     .fields = (VMStateField[]) {
859         VMSTATE_UINT8(perpendicular, FDrive),
860         VMSTATE_END_OF_LIST()
861     }
862 };
863 
864 static int fdrive_post_load(void *opaque, int version_id)
865 {
866     fd_revalidate(opaque);
867     return 0;
868 }
869 
870 static const VMStateDescription vmstate_fdrive = {
871     .name = "fdrive",
872     .version_id = 1,
873     .minimum_version_id = 1,
874     .post_load = fdrive_post_load,
875     .fields = (VMStateField[]) {
876         VMSTATE_UINT8(head, FDrive),
877         VMSTATE_UINT8(track, FDrive),
878         VMSTATE_UINT8(sect, FDrive),
879         VMSTATE_END_OF_LIST()
880     },
881     .subsections = (const VMStateDescription*[]) {
882         &vmstate_fdrive_media_changed,
883         &vmstate_fdrive_media_rate,
884         &vmstate_fdrive_perpendicular,
885         NULL
886     }
887 };
888 
889 /*
890  * Reconstructs the phase from register values according to the logic that was
891  * implemented in qemu 2.3. This is the default value that is used if the phase
892  * subsection is not present on migration.
893  *
894  * Don't change this function to reflect newer qemu versions, it is part of
895  * the migration ABI.
896  */
897 static int reconstruct_phase(FDCtrl *fdctrl)
898 {
899     if (fdctrl->msr & FD_MSR_NONDMA) {
900         return FD_PHASE_EXECUTION;
901     } else if ((fdctrl->msr & FD_MSR_RQM) == 0) {
902         /* qemu 2.3 disabled RQM only during DMA transfers */
903         return FD_PHASE_EXECUTION;
904     } else if (fdctrl->msr & FD_MSR_DIO) {
905         return FD_PHASE_RESULT;
906     } else {
907         return FD_PHASE_COMMAND;
908     }
909 }
910 
911 static void fdc_pre_save(void *opaque)
912 {
913     FDCtrl *s = opaque;
914 
915     s->dor_vmstate = s->dor | GET_CUR_DRV(s);
916 }
917 
918 static int fdc_pre_load(void *opaque)
919 {
920     FDCtrl *s = opaque;
921     s->phase = FD_PHASE_RECONSTRUCT;
922     return 0;
923 }
924 
925 static int fdc_post_load(void *opaque, int version_id)
926 {
927     FDCtrl *s = opaque;
928 
929     SET_CUR_DRV(s, s->dor_vmstate & FD_DOR_SELMASK);
930     s->dor = s->dor_vmstate & ~FD_DOR_SELMASK;
931 
932     if (s->phase == FD_PHASE_RECONSTRUCT) {
933         s->phase = reconstruct_phase(s);
934     }
935 
936     return 0;
937 }
938 
939 static bool fdc_reset_sensei_needed(void *opaque)
940 {
941     FDCtrl *s = opaque;
942 
943     return s->reset_sensei != 0;
944 }
945 
946 static const VMStateDescription vmstate_fdc_reset_sensei = {
947     .name = "fdc/reset_sensei",
948     .version_id = 1,
949     .minimum_version_id = 1,
950     .needed = fdc_reset_sensei_needed,
951     .fields = (VMStateField[]) {
952         VMSTATE_INT32(reset_sensei, FDCtrl),
953         VMSTATE_END_OF_LIST()
954     }
955 };
956 
957 static bool fdc_result_timer_needed(void *opaque)
958 {
959     FDCtrl *s = opaque;
960 
961     return timer_pending(s->result_timer);
962 }
963 
964 static const VMStateDescription vmstate_fdc_result_timer = {
965     .name = "fdc/result_timer",
966     .version_id = 1,
967     .minimum_version_id = 1,
968     .needed = fdc_result_timer_needed,
969     .fields = (VMStateField[]) {
970         VMSTATE_TIMER_PTR(result_timer, FDCtrl),
971         VMSTATE_END_OF_LIST()
972     }
973 };
974 
975 static bool fdc_phase_needed(void *opaque)
976 {
977     FDCtrl *fdctrl = opaque;
978 
979     return reconstruct_phase(fdctrl) != fdctrl->phase;
980 }
981 
982 static const VMStateDescription vmstate_fdc_phase = {
983     .name = "fdc/phase",
984     .version_id = 1,
985     .minimum_version_id = 1,
986     .needed = fdc_phase_needed,
987     .fields = (VMStateField[]) {
988         VMSTATE_UINT8(phase, FDCtrl),
989         VMSTATE_END_OF_LIST()
990     }
991 };
992 
993 static const VMStateDescription vmstate_fdc = {
994     .name = "fdc",
995     .version_id = 2,
996     .minimum_version_id = 2,
997     .pre_save = fdc_pre_save,
998     .pre_load = fdc_pre_load,
999     .post_load = fdc_post_load,
1000     .fields = (VMStateField[]) {
1001         /* Controller State */
1002         VMSTATE_UINT8(sra, FDCtrl),
1003         VMSTATE_UINT8(srb, FDCtrl),
1004         VMSTATE_UINT8(dor_vmstate, FDCtrl),
1005         VMSTATE_UINT8(tdr, FDCtrl),
1006         VMSTATE_UINT8(dsr, FDCtrl),
1007         VMSTATE_UINT8(msr, FDCtrl),
1008         VMSTATE_UINT8(status0, FDCtrl),
1009         VMSTATE_UINT8(status1, FDCtrl),
1010         VMSTATE_UINT8(status2, FDCtrl),
1011         /* Command FIFO */
1012         VMSTATE_VARRAY_INT32(fifo, FDCtrl, fifo_size, 0, vmstate_info_uint8,
1013                              uint8_t),
1014         VMSTATE_UINT32(data_pos, FDCtrl),
1015         VMSTATE_UINT32(data_len, FDCtrl),
1016         VMSTATE_UINT8(data_state, FDCtrl),
1017         VMSTATE_UINT8(data_dir, FDCtrl),
1018         VMSTATE_UINT8(eot, FDCtrl),
1019         /* States kept only to be returned back */
1020         VMSTATE_UINT8(timer0, FDCtrl),
1021         VMSTATE_UINT8(timer1, FDCtrl),
1022         VMSTATE_UINT8(precomp_trk, FDCtrl),
1023         VMSTATE_UINT8(config, FDCtrl),
1024         VMSTATE_UINT8(lock, FDCtrl),
1025         VMSTATE_UINT8(pwrd, FDCtrl),
1026         VMSTATE_UINT8_EQUAL(num_floppies, FDCtrl),
1027         VMSTATE_STRUCT_ARRAY(drives, FDCtrl, MAX_FD, 1,
1028                              vmstate_fdrive, FDrive),
1029         VMSTATE_END_OF_LIST()
1030     },
1031     .subsections = (const VMStateDescription*[]) {
1032         &vmstate_fdc_reset_sensei,
1033         &vmstate_fdc_result_timer,
1034         &vmstate_fdc_phase,
1035         NULL
1036     }
1037 };
1038 
1039 static void fdctrl_external_reset_sysbus(DeviceState *d)
1040 {
1041     FDCtrlSysBus *sys = SYSBUS_FDC(d);
1042     FDCtrl *s = &sys->state;
1043 
1044     fdctrl_reset(s, 0);
1045 }
1046 
1047 static void fdctrl_external_reset_isa(DeviceState *d)
1048 {
1049     FDCtrlISABus *isa = ISA_FDC(d);
1050     FDCtrl *s = &isa->state;
1051 
1052     fdctrl_reset(s, 0);
1053 }
1054 
1055 static void fdctrl_handle_tc(void *opaque, int irq, int level)
1056 {
1057     //FDCtrl *s = opaque;
1058 
1059     if (level) {
1060         // XXX
1061         FLOPPY_DPRINTF("TC pulsed\n");
1062     }
1063 }
1064 
1065 /* Change IRQ state */
1066 static void fdctrl_reset_irq(FDCtrl *fdctrl)
1067 {
1068     fdctrl->status0 = 0;
1069     if (!(fdctrl->sra & FD_SRA_INTPEND))
1070         return;
1071     FLOPPY_DPRINTF("Reset interrupt\n");
1072     qemu_set_irq(fdctrl->irq, 0);
1073     fdctrl->sra &= ~FD_SRA_INTPEND;
1074 }
1075 
1076 static void fdctrl_raise_irq(FDCtrl *fdctrl)
1077 {
1078     if (!(fdctrl->sra & FD_SRA_INTPEND)) {
1079         qemu_set_irq(fdctrl->irq, 1);
1080         fdctrl->sra |= FD_SRA_INTPEND;
1081     }
1082 
1083     fdctrl->reset_sensei = 0;
1084     FLOPPY_DPRINTF("Set interrupt status to 0x%02x\n", fdctrl->status0);
1085 }
1086 
1087 /* Reset controller */
1088 static void fdctrl_reset(FDCtrl *fdctrl, int do_irq)
1089 {
1090     int i;
1091 
1092     FLOPPY_DPRINTF("reset controller\n");
1093     fdctrl_reset_irq(fdctrl);
1094     /* Initialise controller */
1095     fdctrl->sra = 0;
1096     fdctrl->srb = 0xc0;
1097     if (!fdctrl->drives[1].blk) {
1098         fdctrl->sra |= FD_SRA_nDRV2;
1099     }
1100     fdctrl->cur_drv = 0;
1101     fdctrl->dor = FD_DOR_nRESET;
1102     fdctrl->dor |= (fdctrl->dma_chann != -1) ? FD_DOR_DMAEN : 0;
1103     fdctrl->msr = FD_MSR_RQM;
1104     fdctrl->reset_sensei = 0;
1105     timer_del(fdctrl->result_timer);
1106     /* FIFO state */
1107     fdctrl->data_pos = 0;
1108     fdctrl->data_len = 0;
1109     fdctrl->data_state = 0;
1110     fdctrl->data_dir = FD_DIR_WRITE;
1111     for (i = 0; i < MAX_FD; i++)
1112         fd_recalibrate(&fdctrl->drives[i]);
1113     fdctrl_to_command_phase(fdctrl);
1114     if (do_irq) {
1115         fdctrl->status0 |= FD_SR0_RDYCHG;
1116         fdctrl_raise_irq(fdctrl);
1117         fdctrl->reset_sensei = FD_RESET_SENSEI_COUNT;
1118     }
1119 }
1120 
1121 static inline FDrive *drv0(FDCtrl *fdctrl)
1122 {
1123     return &fdctrl->drives[(fdctrl->tdr & FD_TDR_BOOTSEL) >> 2];
1124 }
1125 
1126 static inline FDrive *drv1(FDCtrl *fdctrl)
1127 {
1128     if ((fdctrl->tdr & FD_TDR_BOOTSEL) < (1 << 2))
1129         return &fdctrl->drives[1];
1130     else
1131         return &fdctrl->drives[0];
1132 }
1133 
1134 #if MAX_FD == 4
1135 static inline FDrive *drv2(FDCtrl *fdctrl)
1136 {
1137     if ((fdctrl->tdr & FD_TDR_BOOTSEL) < (2 << 2))
1138         return &fdctrl->drives[2];
1139     else
1140         return &fdctrl->drives[1];
1141 }
1142 
1143 static inline FDrive *drv3(FDCtrl *fdctrl)
1144 {
1145     if ((fdctrl->tdr & FD_TDR_BOOTSEL) < (3 << 2))
1146         return &fdctrl->drives[3];
1147     else
1148         return &fdctrl->drives[2];
1149 }
1150 #endif
1151 
1152 static FDrive *get_cur_drv(FDCtrl *fdctrl)
1153 {
1154     switch (fdctrl->cur_drv) {
1155         case 0: return drv0(fdctrl);
1156         case 1: return drv1(fdctrl);
1157 #if MAX_FD == 4
1158         case 2: return drv2(fdctrl);
1159         case 3: return drv3(fdctrl);
1160 #endif
1161         default: return NULL;
1162     }
1163 }
1164 
1165 /* Status A register : 0x00 (read-only) */
1166 static uint32_t fdctrl_read_statusA(FDCtrl *fdctrl)
1167 {
1168     uint32_t retval = fdctrl->sra;
1169 
1170     FLOPPY_DPRINTF("status register A: 0x%02x\n", retval);
1171 
1172     return retval;
1173 }
1174 
1175 /* Status B register : 0x01 (read-only) */
1176 static uint32_t fdctrl_read_statusB(FDCtrl *fdctrl)
1177 {
1178     uint32_t retval = fdctrl->srb;
1179 
1180     FLOPPY_DPRINTF("status register B: 0x%02x\n", retval);
1181 
1182     return retval;
1183 }
1184 
1185 /* Digital output register : 0x02 */
1186 static uint32_t fdctrl_read_dor(FDCtrl *fdctrl)
1187 {
1188     uint32_t retval = fdctrl->dor;
1189 
1190     /* Selected drive */
1191     retval |= fdctrl->cur_drv;
1192     FLOPPY_DPRINTF("digital output register: 0x%02x\n", retval);
1193 
1194     return retval;
1195 }
1196 
1197 static void fdctrl_write_dor(FDCtrl *fdctrl, uint32_t value)
1198 {
1199     FLOPPY_DPRINTF("digital output register set to 0x%02x\n", value);
1200 
1201     /* Motors */
1202     if (value & FD_DOR_MOTEN0)
1203         fdctrl->srb |= FD_SRB_MTR0;
1204     else
1205         fdctrl->srb &= ~FD_SRB_MTR0;
1206     if (value & FD_DOR_MOTEN1)
1207         fdctrl->srb |= FD_SRB_MTR1;
1208     else
1209         fdctrl->srb &= ~FD_SRB_MTR1;
1210 
1211     /* Drive */
1212     if (value & 1)
1213         fdctrl->srb |= FD_SRB_DR0;
1214     else
1215         fdctrl->srb &= ~FD_SRB_DR0;
1216 
1217     /* Reset */
1218     if (!(value & FD_DOR_nRESET)) {
1219         if (fdctrl->dor & FD_DOR_nRESET) {
1220             FLOPPY_DPRINTF("controller enter RESET state\n");
1221         }
1222     } else {
1223         if (!(fdctrl->dor & FD_DOR_nRESET)) {
1224             FLOPPY_DPRINTF("controller out of RESET state\n");
1225             fdctrl_reset(fdctrl, 1);
1226             fdctrl->dsr &= ~FD_DSR_PWRDOWN;
1227         }
1228     }
1229     /* Selected drive */
1230     fdctrl->cur_drv = value & FD_DOR_SELMASK;
1231 
1232     fdctrl->dor = value;
1233 }
1234 
1235 /* Tape drive register : 0x03 */
1236 static uint32_t fdctrl_read_tape(FDCtrl *fdctrl)
1237 {
1238     uint32_t retval = fdctrl->tdr;
1239 
1240     FLOPPY_DPRINTF("tape drive register: 0x%02x\n", retval);
1241 
1242     return retval;
1243 }
1244 
1245 static void fdctrl_write_tape(FDCtrl *fdctrl, uint32_t value)
1246 {
1247     /* Reset mode */
1248     if (!(fdctrl->dor & FD_DOR_nRESET)) {
1249         FLOPPY_DPRINTF("Floppy controller in RESET state !\n");
1250         return;
1251     }
1252     FLOPPY_DPRINTF("tape drive register set to 0x%02x\n", value);
1253     /* Disk boot selection indicator */
1254     fdctrl->tdr = value & FD_TDR_BOOTSEL;
1255     /* Tape indicators: never allow */
1256 }
1257 
1258 /* Main status register : 0x04 (read) */
1259 static uint32_t fdctrl_read_main_status(FDCtrl *fdctrl)
1260 {
1261     uint32_t retval = fdctrl->msr;
1262 
1263     fdctrl->dsr &= ~FD_DSR_PWRDOWN;
1264     fdctrl->dor |= FD_DOR_nRESET;
1265 
1266     FLOPPY_DPRINTF("main status register: 0x%02x\n", retval);
1267 
1268     return retval;
1269 }
1270 
1271 /* Data select rate register : 0x04 (write) */
1272 static void fdctrl_write_rate(FDCtrl *fdctrl, uint32_t value)
1273 {
1274     /* Reset mode */
1275     if (!(fdctrl->dor & FD_DOR_nRESET)) {
1276         FLOPPY_DPRINTF("Floppy controller in RESET state !\n");
1277         return;
1278     }
1279     FLOPPY_DPRINTF("select rate register set to 0x%02x\n", value);
1280     /* Reset: autoclear */
1281     if (value & FD_DSR_SWRESET) {
1282         fdctrl->dor &= ~FD_DOR_nRESET;
1283         fdctrl_reset(fdctrl, 1);
1284         fdctrl->dor |= FD_DOR_nRESET;
1285     }
1286     if (value & FD_DSR_PWRDOWN) {
1287         fdctrl_reset(fdctrl, 1);
1288     }
1289     fdctrl->dsr = value;
1290 }
1291 
1292 /* Configuration control register: 0x07 (write) */
1293 static void fdctrl_write_ccr(FDCtrl *fdctrl, uint32_t value)
1294 {
1295     /* Reset mode */
1296     if (!(fdctrl->dor & FD_DOR_nRESET)) {
1297         FLOPPY_DPRINTF("Floppy controller in RESET state !\n");
1298         return;
1299     }
1300     FLOPPY_DPRINTF("configuration control register set to 0x%02x\n", value);
1301 
1302     /* Only the rate selection bits used in AT mode, and we
1303      * store those in the DSR.
1304      */
1305     fdctrl->dsr = (fdctrl->dsr & ~FD_DSR_DRATEMASK) |
1306                   (value & FD_DSR_DRATEMASK);
1307 }
1308 
1309 static int fdctrl_media_changed(FDrive *drv)
1310 {
1311     return drv->media_changed;
1312 }
1313 
1314 /* Digital input register : 0x07 (read-only) */
1315 static uint32_t fdctrl_read_dir(FDCtrl *fdctrl)
1316 {
1317     uint32_t retval = 0;
1318 
1319     if (fdctrl_media_changed(get_cur_drv(fdctrl))) {
1320         retval |= FD_DIR_DSKCHG;
1321     }
1322     if (retval != 0) {
1323         FLOPPY_DPRINTF("Floppy digital input register: 0x%02x\n", retval);
1324     }
1325 
1326     return retval;
1327 }
1328 
1329 /* Clear the FIFO and update the state for receiving the next command */
1330 static void fdctrl_to_command_phase(FDCtrl *fdctrl)
1331 {
1332     fdctrl->phase = FD_PHASE_COMMAND;
1333     fdctrl->data_dir = FD_DIR_WRITE;
1334     fdctrl->data_pos = 0;
1335     fdctrl->data_len = 1; /* Accept command byte, adjust for params later */
1336     fdctrl->msr &= ~(FD_MSR_CMDBUSY | FD_MSR_DIO);
1337     fdctrl->msr |= FD_MSR_RQM;
1338 }
1339 
1340 /* Update the state to allow the guest to read out the command status.
1341  * @fifo_len is the number of result bytes to be read out. */
1342 static void fdctrl_to_result_phase(FDCtrl *fdctrl, int fifo_len)
1343 {
1344     fdctrl->phase = FD_PHASE_RESULT;
1345     fdctrl->data_dir = FD_DIR_READ;
1346     fdctrl->data_len = fifo_len;
1347     fdctrl->data_pos = 0;
1348     fdctrl->msr |= FD_MSR_CMDBUSY | FD_MSR_RQM | FD_MSR_DIO;
1349 }
1350 
1351 /* Set an error: unimplemented/unknown command */
1352 static void fdctrl_unimplemented(FDCtrl *fdctrl, int direction)
1353 {
1354     qemu_log_mask(LOG_UNIMP, "fdc: unimplemented command 0x%02x\n",
1355                   fdctrl->fifo[0]);
1356     fdctrl->fifo[0] = FD_SR0_INVCMD;
1357     fdctrl_to_result_phase(fdctrl, 1);
1358 }
1359 
1360 /* Seek to next sector
1361  * returns 0 when end of track reached (for DBL_SIDES on head 1)
1362  * otherwise returns 1
1363  */
1364 static int fdctrl_seek_to_next_sect(FDCtrl *fdctrl, FDrive *cur_drv)
1365 {
1366     FLOPPY_DPRINTF("seek to next sector (%d %02x %02x => %d)\n",
1367                    cur_drv->head, cur_drv->track, cur_drv->sect,
1368                    fd_sector(cur_drv));
1369     /* XXX: cur_drv->sect >= cur_drv->last_sect should be an
1370        error in fact */
1371     uint8_t new_head = cur_drv->head;
1372     uint8_t new_track = cur_drv->track;
1373     uint8_t new_sect = cur_drv->sect;
1374 
1375     int ret = 1;
1376 
1377     if (new_sect >= cur_drv->last_sect ||
1378         new_sect == fdctrl->eot) {
1379         new_sect = 1;
1380         if (FD_MULTI_TRACK(fdctrl->data_state)) {
1381             if (new_head == 0 &&
1382                 (cur_drv->flags & FDISK_DBL_SIDES) != 0) {
1383                 new_head = 1;
1384             } else {
1385                 new_head = 0;
1386                 new_track++;
1387                 fdctrl->status0 |= FD_SR0_SEEK;
1388                 if ((cur_drv->flags & FDISK_DBL_SIDES) == 0) {
1389                     ret = 0;
1390                 }
1391             }
1392         } else {
1393             fdctrl->status0 |= FD_SR0_SEEK;
1394             new_track++;
1395             ret = 0;
1396         }
1397         if (ret == 1) {
1398             FLOPPY_DPRINTF("seek to next track (%d %02x %02x => %d)\n",
1399                     new_head, new_track, new_sect, fd_sector(cur_drv));
1400         }
1401     } else {
1402         new_sect++;
1403     }
1404     fd_seek(cur_drv, new_head, new_track, new_sect, 1);
1405     return ret;
1406 }
1407 
1408 /* Callback for transfer end (stop or abort) */
1409 static void fdctrl_stop_transfer(FDCtrl *fdctrl, uint8_t status0,
1410                                  uint8_t status1, uint8_t status2)
1411 {
1412     FDrive *cur_drv;
1413     cur_drv = get_cur_drv(fdctrl);
1414 
1415     fdctrl->status0 &= ~(FD_SR0_DS0 | FD_SR0_DS1 | FD_SR0_HEAD);
1416     fdctrl->status0 |= GET_CUR_DRV(fdctrl);
1417     if (cur_drv->head) {
1418         fdctrl->status0 |= FD_SR0_HEAD;
1419     }
1420     fdctrl->status0 |= status0;
1421 
1422     FLOPPY_DPRINTF("transfer status: %02x %02x %02x (%02x)\n",
1423                    status0, status1, status2, fdctrl->status0);
1424     fdctrl->fifo[0] = fdctrl->status0;
1425     fdctrl->fifo[1] = status1;
1426     fdctrl->fifo[2] = status2;
1427     fdctrl->fifo[3] = cur_drv->track;
1428     fdctrl->fifo[4] = cur_drv->head;
1429     fdctrl->fifo[5] = cur_drv->sect;
1430     fdctrl->fifo[6] = FD_SECTOR_SC;
1431     fdctrl->data_dir = FD_DIR_READ;
1432     if (!(fdctrl->msr & FD_MSR_NONDMA)) {
1433         IsaDmaClass *k = ISADMA_GET_CLASS(fdctrl->dma);
1434         k->release_DREQ(fdctrl->dma, fdctrl->dma_chann);
1435     }
1436     fdctrl->msr |= FD_MSR_RQM | FD_MSR_DIO;
1437     fdctrl->msr &= ~FD_MSR_NONDMA;
1438 
1439     fdctrl_to_result_phase(fdctrl, 7);
1440     fdctrl_raise_irq(fdctrl);
1441 }
1442 
1443 /* Prepare a data transfer (either DMA or FIFO) */
1444 static void fdctrl_start_transfer(FDCtrl *fdctrl, int direction)
1445 {
1446     FDrive *cur_drv;
1447     uint8_t kh, kt, ks;
1448 
1449     SET_CUR_DRV(fdctrl, fdctrl->fifo[1] & FD_DOR_SELMASK);
1450     cur_drv = get_cur_drv(fdctrl);
1451     kt = fdctrl->fifo[2];
1452     kh = fdctrl->fifo[3];
1453     ks = fdctrl->fifo[4];
1454     FLOPPY_DPRINTF("Start transfer at %d %d %02x %02x (%d)\n",
1455                    GET_CUR_DRV(fdctrl), kh, kt, ks,
1456                    fd_sector_calc(kh, kt, ks, cur_drv->last_sect,
1457                                   NUM_SIDES(cur_drv)));
1458     switch (fd_seek(cur_drv, kh, kt, ks, fdctrl->config & FD_CONFIG_EIS)) {
1459     case 2:
1460         /* sect too big */
1461         fdctrl_stop_transfer(fdctrl, FD_SR0_ABNTERM, 0x00, 0x00);
1462         fdctrl->fifo[3] = kt;
1463         fdctrl->fifo[4] = kh;
1464         fdctrl->fifo[5] = ks;
1465         return;
1466     case 3:
1467         /* track too big */
1468         fdctrl_stop_transfer(fdctrl, FD_SR0_ABNTERM, FD_SR1_EC, 0x00);
1469         fdctrl->fifo[3] = kt;
1470         fdctrl->fifo[4] = kh;
1471         fdctrl->fifo[5] = ks;
1472         return;
1473     case 4:
1474         /* No seek enabled */
1475         fdctrl_stop_transfer(fdctrl, FD_SR0_ABNTERM, 0x00, 0x00);
1476         fdctrl->fifo[3] = kt;
1477         fdctrl->fifo[4] = kh;
1478         fdctrl->fifo[5] = ks;
1479         return;
1480     case 1:
1481         fdctrl->status0 |= FD_SR0_SEEK;
1482         break;
1483     default:
1484         break;
1485     }
1486 
1487     /* Check the data rate. If the programmed data rate does not match
1488      * the currently inserted medium, the operation has to fail. */
1489     if (fdctrl->check_media_rate &&
1490         (fdctrl->dsr & FD_DSR_DRATEMASK) != cur_drv->media_rate) {
1491         FLOPPY_DPRINTF("data rate mismatch (fdc=%d, media=%d)\n",
1492                        fdctrl->dsr & FD_DSR_DRATEMASK, cur_drv->media_rate);
1493         fdctrl_stop_transfer(fdctrl, FD_SR0_ABNTERM, FD_SR1_MA, 0x00);
1494         fdctrl->fifo[3] = kt;
1495         fdctrl->fifo[4] = kh;
1496         fdctrl->fifo[5] = ks;
1497         return;
1498     }
1499 
1500     /* Set the FIFO state */
1501     fdctrl->data_dir = direction;
1502     fdctrl->data_pos = 0;
1503     assert(fdctrl->msr & FD_MSR_CMDBUSY);
1504     if (fdctrl->fifo[0] & 0x80)
1505         fdctrl->data_state |= FD_STATE_MULTI;
1506     else
1507         fdctrl->data_state &= ~FD_STATE_MULTI;
1508     if (fdctrl->fifo[5] == 0) {
1509         fdctrl->data_len = fdctrl->fifo[8];
1510     } else {
1511         int tmp;
1512         fdctrl->data_len = 128 << (fdctrl->fifo[5] > 7 ? 7 : fdctrl->fifo[5]);
1513         tmp = (fdctrl->fifo[6] - ks + 1);
1514         if (fdctrl->fifo[0] & 0x80)
1515             tmp += fdctrl->fifo[6];
1516         fdctrl->data_len *= tmp;
1517     }
1518     fdctrl->eot = fdctrl->fifo[6];
1519     if (fdctrl->dor & FD_DOR_DMAEN) {
1520         IsaDmaTransferMode dma_mode;
1521         IsaDmaClass *k = ISADMA_GET_CLASS(fdctrl->dma);
1522         bool dma_mode_ok;
1523         /* DMA transfer are enabled. Check if DMA channel is well programmed */
1524         dma_mode = k->get_transfer_mode(fdctrl->dma, fdctrl->dma_chann);
1525         FLOPPY_DPRINTF("dma_mode=%d direction=%d (%d - %d)\n",
1526                        dma_mode, direction,
1527                        (128 << fdctrl->fifo[5]) *
1528                        (cur_drv->last_sect - ks + 1), fdctrl->data_len);
1529         switch (direction) {
1530         case FD_DIR_SCANE:
1531         case FD_DIR_SCANL:
1532         case FD_DIR_SCANH:
1533             dma_mode_ok = (dma_mode == ISADMA_TRANSFER_VERIFY);
1534             break;
1535         case FD_DIR_WRITE:
1536             dma_mode_ok = (dma_mode == ISADMA_TRANSFER_WRITE);
1537             break;
1538         case FD_DIR_READ:
1539             dma_mode_ok = (dma_mode == ISADMA_TRANSFER_READ);
1540             break;
1541         case FD_DIR_VERIFY:
1542             dma_mode_ok = true;
1543             break;
1544         default:
1545             dma_mode_ok = false;
1546             break;
1547         }
1548         if (dma_mode_ok) {
1549             /* No access is allowed until DMA transfer has completed */
1550             fdctrl->msr &= ~FD_MSR_RQM;
1551             if (direction != FD_DIR_VERIFY) {
1552                 /* Now, we just have to wait for the DMA controller to
1553                  * recall us...
1554                  */
1555                 k->hold_DREQ(fdctrl->dma, fdctrl->dma_chann);
1556                 k->schedule(fdctrl->dma);
1557             } else {
1558                 /* Start transfer */
1559                 fdctrl_transfer_handler(fdctrl, fdctrl->dma_chann, 0,
1560                                         fdctrl->data_len);
1561             }
1562             return;
1563         } else {
1564             FLOPPY_DPRINTF("bad dma_mode=%d direction=%d\n", dma_mode,
1565                            direction);
1566         }
1567     }
1568     FLOPPY_DPRINTF("start non-DMA transfer\n");
1569     fdctrl->msr |= FD_MSR_NONDMA | FD_MSR_RQM;
1570     if (direction != FD_DIR_WRITE)
1571         fdctrl->msr |= FD_MSR_DIO;
1572     /* IO based transfer: calculate len */
1573     fdctrl_raise_irq(fdctrl);
1574 }
1575 
1576 /* Prepare a transfer of deleted data */
1577 static void fdctrl_start_transfer_del(FDCtrl *fdctrl, int direction)
1578 {
1579     qemu_log_mask(LOG_UNIMP, "fdctrl_start_transfer_del() unimplemented\n");
1580 
1581     /* We don't handle deleted data,
1582      * so we don't return *ANYTHING*
1583      */
1584     fdctrl_stop_transfer(fdctrl, FD_SR0_ABNTERM | FD_SR0_SEEK, 0x00, 0x00);
1585 }
1586 
1587 /* handlers for DMA transfers */
1588 static int fdctrl_transfer_handler (void *opaque, int nchan,
1589                                     int dma_pos, int dma_len)
1590 {
1591     FDCtrl *fdctrl;
1592     FDrive *cur_drv;
1593     int len, start_pos, rel_pos;
1594     uint8_t status0 = 0x00, status1 = 0x00, status2 = 0x00;
1595     IsaDmaClass *k;
1596 
1597     fdctrl = opaque;
1598     if (fdctrl->msr & FD_MSR_RQM) {
1599         FLOPPY_DPRINTF("Not in DMA transfer mode !\n");
1600         return 0;
1601     }
1602     k = ISADMA_GET_CLASS(fdctrl->dma);
1603     cur_drv = get_cur_drv(fdctrl);
1604     if (fdctrl->data_dir == FD_DIR_SCANE || fdctrl->data_dir == FD_DIR_SCANL ||
1605         fdctrl->data_dir == FD_DIR_SCANH)
1606         status2 = FD_SR2_SNS;
1607     if (dma_len > fdctrl->data_len)
1608         dma_len = fdctrl->data_len;
1609     if (cur_drv->blk == NULL) {
1610         if (fdctrl->data_dir == FD_DIR_WRITE)
1611             fdctrl_stop_transfer(fdctrl, FD_SR0_ABNTERM | FD_SR0_SEEK, 0x00, 0x00);
1612         else
1613             fdctrl_stop_transfer(fdctrl, FD_SR0_ABNTERM, 0x00, 0x00);
1614         len = 0;
1615         goto transfer_error;
1616     }
1617     rel_pos = fdctrl->data_pos % FD_SECTOR_LEN;
1618     for (start_pos = fdctrl->data_pos; fdctrl->data_pos < dma_len;) {
1619         len = dma_len - fdctrl->data_pos;
1620         if (len + rel_pos > FD_SECTOR_LEN)
1621             len = FD_SECTOR_LEN - rel_pos;
1622         FLOPPY_DPRINTF("copy %d bytes (%d %d %d) %d pos %d %02x "
1623                        "(%d-0x%08x 0x%08x)\n", len, dma_len, fdctrl->data_pos,
1624                        fdctrl->data_len, GET_CUR_DRV(fdctrl), cur_drv->head,
1625                        cur_drv->track, cur_drv->sect, fd_sector(cur_drv),
1626                        fd_sector(cur_drv) * FD_SECTOR_LEN);
1627         if (fdctrl->data_dir != FD_DIR_WRITE ||
1628             len < FD_SECTOR_LEN || rel_pos != 0) {
1629             /* READ & SCAN commands and realign to a sector for WRITE */
1630             if (blk_read(cur_drv->blk, fd_sector(cur_drv),
1631                          fdctrl->fifo, 1) < 0) {
1632                 FLOPPY_DPRINTF("Floppy: error getting sector %d\n",
1633                                fd_sector(cur_drv));
1634                 /* Sure, image size is too small... */
1635                 memset(fdctrl->fifo, 0, FD_SECTOR_LEN);
1636             }
1637         }
1638         switch (fdctrl->data_dir) {
1639         case FD_DIR_READ:
1640             /* READ commands */
1641             k->write_memory(fdctrl->dma, nchan, fdctrl->fifo + rel_pos,
1642                             fdctrl->data_pos, len);
1643             break;
1644         case FD_DIR_WRITE:
1645             /* WRITE commands */
1646             if (cur_drv->ro) {
1647                 /* Handle readonly medium early, no need to do DMA, touch the
1648                  * LED or attempt any writes. A real floppy doesn't attempt
1649                  * to write to readonly media either. */
1650                 fdctrl_stop_transfer(fdctrl,
1651                                      FD_SR0_ABNTERM | FD_SR0_SEEK, FD_SR1_NW,
1652                                      0x00);
1653                 goto transfer_error;
1654             }
1655 
1656             k->read_memory(fdctrl->dma, nchan, fdctrl->fifo + rel_pos,
1657                            fdctrl->data_pos, len);
1658             if (blk_write(cur_drv->blk, fd_sector(cur_drv),
1659                           fdctrl->fifo, 1) < 0) {
1660                 FLOPPY_DPRINTF("error writing sector %d\n",
1661                                fd_sector(cur_drv));
1662                 fdctrl_stop_transfer(fdctrl, FD_SR0_ABNTERM | FD_SR0_SEEK, 0x00, 0x00);
1663                 goto transfer_error;
1664             }
1665             break;
1666         case FD_DIR_VERIFY:
1667             /* VERIFY commands */
1668             break;
1669         default:
1670             /* SCAN commands */
1671             {
1672                 uint8_t tmpbuf[FD_SECTOR_LEN];
1673                 int ret;
1674                 k->read_memory(fdctrl->dma, nchan, tmpbuf, fdctrl->data_pos,
1675                                len);
1676                 ret = memcmp(tmpbuf, fdctrl->fifo + rel_pos, len);
1677                 if (ret == 0) {
1678                     status2 = FD_SR2_SEH;
1679                     goto end_transfer;
1680                 }
1681                 if ((ret < 0 && fdctrl->data_dir == FD_DIR_SCANL) ||
1682                     (ret > 0 && fdctrl->data_dir == FD_DIR_SCANH)) {
1683                     status2 = 0x00;
1684                     goto end_transfer;
1685                 }
1686             }
1687             break;
1688         }
1689         fdctrl->data_pos += len;
1690         rel_pos = fdctrl->data_pos % FD_SECTOR_LEN;
1691         if (rel_pos == 0) {
1692             /* Seek to next sector */
1693             if (!fdctrl_seek_to_next_sect(fdctrl, cur_drv))
1694                 break;
1695         }
1696     }
1697  end_transfer:
1698     len = fdctrl->data_pos - start_pos;
1699     FLOPPY_DPRINTF("end transfer %d %d %d\n",
1700                    fdctrl->data_pos, len, fdctrl->data_len);
1701     if (fdctrl->data_dir == FD_DIR_SCANE ||
1702         fdctrl->data_dir == FD_DIR_SCANL ||
1703         fdctrl->data_dir == FD_DIR_SCANH)
1704         status2 = FD_SR2_SEH;
1705     fdctrl->data_len -= len;
1706     fdctrl_stop_transfer(fdctrl, status0, status1, status2);
1707  transfer_error:
1708 
1709     return len;
1710 }
1711 
1712 /* Data register : 0x05 */
1713 static uint32_t fdctrl_read_data(FDCtrl *fdctrl)
1714 {
1715     FDrive *cur_drv;
1716     uint32_t retval = 0;
1717     uint32_t pos;
1718 
1719     cur_drv = get_cur_drv(fdctrl);
1720     fdctrl->dsr &= ~FD_DSR_PWRDOWN;
1721     if (!(fdctrl->msr & FD_MSR_RQM) || !(fdctrl->msr & FD_MSR_DIO)) {
1722         FLOPPY_DPRINTF("error: controller not ready for reading\n");
1723         return 0;
1724     }
1725 
1726     /* If data_len spans multiple sectors, the current position in the FIFO
1727      * wraps around while fdctrl->data_pos is the real position in the whole
1728      * request. */
1729     pos = fdctrl->data_pos;
1730     pos %= FD_SECTOR_LEN;
1731 
1732     switch (fdctrl->phase) {
1733     case FD_PHASE_EXECUTION:
1734         assert(fdctrl->msr & FD_MSR_NONDMA);
1735         if (pos == 0) {
1736             if (fdctrl->data_pos != 0)
1737                 if (!fdctrl_seek_to_next_sect(fdctrl, cur_drv)) {
1738                     FLOPPY_DPRINTF("error seeking to next sector %d\n",
1739                                    fd_sector(cur_drv));
1740                     return 0;
1741                 }
1742             if (blk_read(cur_drv->blk, fd_sector(cur_drv), fdctrl->fifo, 1)
1743                 < 0) {
1744                 FLOPPY_DPRINTF("error getting sector %d\n",
1745                                fd_sector(cur_drv));
1746                 /* Sure, image size is too small... */
1747                 memset(fdctrl->fifo, 0, FD_SECTOR_LEN);
1748             }
1749         }
1750 
1751         if (++fdctrl->data_pos == fdctrl->data_len) {
1752             fdctrl->msr &= ~FD_MSR_RQM;
1753             fdctrl_stop_transfer(fdctrl, 0x00, 0x00, 0x00);
1754         }
1755         break;
1756 
1757     case FD_PHASE_RESULT:
1758         assert(!(fdctrl->msr & FD_MSR_NONDMA));
1759         if (++fdctrl->data_pos == fdctrl->data_len) {
1760             fdctrl->msr &= ~FD_MSR_RQM;
1761             fdctrl_to_command_phase(fdctrl);
1762             fdctrl_reset_irq(fdctrl);
1763         }
1764         break;
1765 
1766     case FD_PHASE_COMMAND:
1767     default:
1768         abort();
1769     }
1770 
1771     retval = fdctrl->fifo[pos];
1772     FLOPPY_DPRINTF("data register: 0x%02x\n", retval);
1773 
1774     return retval;
1775 }
1776 
1777 static void fdctrl_format_sector(FDCtrl *fdctrl)
1778 {
1779     FDrive *cur_drv;
1780     uint8_t kh, kt, ks;
1781 
1782     SET_CUR_DRV(fdctrl, fdctrl->fifo[1] & FD_DOR_SELMASK);
1783     cur_drv = get_cur_drv(fdctrl);
1784     kt = fdctrl->fifo[6];
1785     kh = fdctrl->fifo[7];
1786     ks = fdctrl->fifo[8];
1787     FLOPPY_DPRINTF("format sector at %d %d %02x %02x (%d)\n",
1788                    GET_CUR_DRV(fdctrl), kh, kt, ks,
1789                    fd_sector_calc(kh, kt, ks, cur_drv->last_sect,
1790                                   NUM_SIDES(cur_drv)));
1791     switch (fd_seek(cur_drv, kh, kt, ks, fdctrl->config & FD_CONFIG_EIS)) {
1792     case 2:
1793         /* sect too big */
1794         fdctrl_stop_transfer(fdctrl, FD_SR0_ABNTERM, 0x00, 0x00);
1795         fdctrl->fifo[3] = kt;
1796         fdctrl->fifo[4] = kh;
1797         fdctrl->fifo[5] = ks;
1798         return;
1799     case 3:
1800         /* track too big */
1801         fdctrl_stop_transfer(fdctrl, FD_SR0_ABNTERM, FD_SR1_EC, 0x00);
1802         fdctrl->fifo[3] = kt;
1803         fdctrl->fifo[4] = kh;
1804         fdctrl->fifo[5] = ks;
1805         return;
1806     case 4:
1807         /* No seek enabled */
1808         fdctrl_stop_transfer(fdctrl, FD_SR0_ABNTERM, 0x00, 0x00);
1809         fdctrl->fifo[3] = kt;
1810         fdctrl->fifo[4] = kh;
1811         fdctrl->fifo[5] = ks;
1812         return;
1813     case 1:
1814         fdctrl->status0 |= FD_SR0_SEEK;
1815         break;
1816     default:
1817         break;
1818     }
1819     memset(fdctrl->fifo, 0, FD_SECTOR_LEN);
1820     if (cur_drv->blk == NULL ||
1821         blk_write(cur_drv->blk, fd_sector(cur_drv), fdctrl->fifo, 1) < 0) {
1822         FLOPPY_DPRINTF("error formatting sector %d\n", fd_sector(cur_drv));
1823         fdctrl_stop_transfer(fdctrl, FD_SR0_ABNTERM | FD_SR0_SEEK, 0x00, 0x00);
1824     } else {
1825         if (cur_drv->sect == cur_drv->last_sect) {
1826             fdctrl->data_state &= ~FD_STATE_FORMAT;
1827             /* Last sector done */
1828             fdctrl_stop_transfer(fdctrl, 0x00, 0x00, 0x00);
1829         } else {
1830             /* More to do */
1831             fdctrl->data_pos = 0;
1832             fdctrl->data_len = 4;
1833         }
1834     }
1835 }
1836 
1837 static void fdctrl_handle_lock(FDCtrl *fdctrl, int direction)
1838 {
1839     fdctrl->lock = (fdctrl->fifo[0] & 0x80) ? 1 : 0;
1840     fdctrl->fifo[0] = fdctrl->lock << 4;
1841     fdctrl_to_result_phase(fdctrl, 1);
1842 }
1843 
1844 static void fdctrl_handle_dumpreg(FDCtrl *fdctrl, int direction)
1845 {
1846     FDrive *cur_drv = get_cur_drv(fdctrl);
1847 
1848     /* Drives position */
1849     fdctrl->fifo[0] = drv0(fdctrl)->track;
1850     fdctrl->fifo[1] = drv1(fdctrl)->track;
1851 #if MAX_FD == 4
1852     fdctrl->fifo[2] = drv2(fdctrl)->track;
1853     fdctrl->fifo[3] = drv3(fdctrl)->track;
1854 #else
1855     fdctrl->fifo[2] = 0;
1856     fdctrl->fifo[3] = 0;
1857 #endif
1858     /* timers */
1859     fdctrl->fifo[4] = fdctrl->timer0;
1860     fdctrl->fifo[5] = (fdctrl->timer1 << 1) | (fdctrl->dor & FD_DOR_DMAEN ? 1 : 0);
1861     fdctrl->fifo[6] = cur_drv->last_sect;
1862     fdctrl->fifo[7] = (fdctrl->lock << 7) |
1863         (cur_drv->perpendicular << 2);
1864     fdctrl->fifo[8] = fdctrl->config;
1865     fdctrl->fifo[9] = fdctrl->precomp_trk;
1866     fdctrl_to_result_phase(fdctrl, 10);
1867 }
1868 
1869 static void fdctrl_handle_version(FDCtrl *fdctrl, int direction)
1870 {
1871     /* Controller's version */
1872     fdctrl->fifo[0] = fdctrl->version;
1873     fdctrl_to_result_phase(fdctrl, 1);
1874 }
1875 
1876 static void fdctrl_handle_partid(FDCtrl *fdctrl, int direction)
1877 {
1878     fdctrl->fifo[0] = 0x41; /* Stepping 1 */
1879     fdctrl_to_result_phase(fdctrl, 1);
1880 }
1881 
1882 static void fdctrl_handle_restore(FDCtrl *fdctrl, int direction)
1883 {
1884     FDrive *cur_drv = get_cur_drv(fdctrl);
1885 
1886     /* Drives position */
1887     drv0(fdctrl)->track = fdctrl->fifo[3];
1888     drv1(fdctrl)->track = fdctrl->fifo[4];
1889 #if MAX_FD == 4
1890     drv2(fdctrl)->track = fdctrl->fifo[5];
1891     drv3(fdctrl)->track = fdctrl->fifo[6];
1892 #endif
1893     /* timers */
1894     fdctrl->timer0 = fdctrl->fifo[7];
1895     fdctrl->timer1 = fdctrl->fifo[8];
1896     cur_drv->last_sect = fdctrl->fifo[9];
1897     fdctrl->lock = fdctrl->fifo[10] >> 7;
1898     cur_drv->perpendicular = (fdctrl->fifo[10] >> 2) & 0xF;
1899     fdctrl->config = fdctrl->fifo[11];
1900     fdctrl->precomp_trk = fdctrl->fifo[12];
1901     fdctrl->pwrd = fdctrl->fifo[13];
1902     fdctrl_to_command_phase(fdctrl);
1903 }
1904 
1905 static void fdctrl_handle_save(FDCtrl *fdctrl, int direction)
1906 {
1907     FDrive *cur_drv = get_cur_drv(fdctrl);
1908 
1909     fdctrl->fifo[0] = 0;
1910     fdctrl->fifo[1] = 0;
1911     /* Drives position */
1912     fdctrl->fifo[2] = drv0(fdctrl)->track;
1913     fdctrl->fifo[3] = drv1(fdctrl)->track;
1914 #if MAX_FD == 4
1915     fdctrl->fifo[4] = drv2(fdctrl)->track;
1916     fdctrl->fifo[5] = drv3(fdctrl)->track;
1917 #else
1918     fdctrl->fifo[4] = 0;
1919     fdctrl->fifo[5] = 0;
1920 #endif
1921     /* timers */
1922     fdctrl->fifo[6] = fdctrl->timer0;
1923     fdctrl->fifo[7] = fdctrl->timer1;
1924     fdctrl->fifo[8] = cur_drv->last_sect;
1925     fdctrl->fifo[9] = (fdctrl->lock << 7) |
1926         (cur_drv->perpendicular << 2);
1927     fdctrl->fifo[10] = fdctrl->config;
1928     fdctrl->fifo[11] = fdctrl->precomp_trk;
1929     fdctrl->fifo[12] = fdctrl->pwrd;
1930     fdctrl->fifo[13] = 0;
1931     fdctrl->fifo[14] = 0;
1932     fdctrl_to_result_phase(fdctrl, 15);
1933 }
1934 
1935 static void fdctrl_handle_readid(FDCtrl *fdctrl, int direction)
1936 {
1937     FDrive *cur_drv = get_cur_drv(fdctrl);
1938 
1939     cur_drv->head = (fdctrl->fifo[1] >> 2) & 1;
1940     timer_mod(fdctrl->result_timer,
1941                    qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + (get_ticks_per_sec() / 50));
1942 }
1943 
1944 static void fdctrl_handle_format_track(FDCtrl *fdctrl, int direction)
1945 {
1946     FDrive *cur_drv;
1947 
1948     SET_CUR_DRV(fdctrl, fdctrl->fifo[1] & FD_DOR_SELMASK);
1949     cur_drv = get_cur_drv(fdctrl);
1950     fdctrl->data_state |= FD_STATE_FORMAT;
1951     if (fdctrl->fifo[0] & 0x80)
1952         fdctrl->data_state |= FD_STATE_MULTI;
1953     else
1954         fdctrl->data_state &= ~FD_STATE_MULTI;
1955     cur_drv->bps =
1956         fdctrl->fifo[2] > 7 ? 16384 : 128 << fdctrl->fifo[2];
1957 #if 0
1958     cur_drv->last_sect =
1959         cur_drv->flags & FDISK_DBL_SIDES ? fdctrl->fifo[3] :
1960         fdctrl->fifo[3] / 2;
1961 #else
1962     cur_drv->last_sect = fdctrl->fifo[3];
1963 #endif
1964     /* TODO: implement format using DMA expected by the Bochs BIOS
1965      * and Linux fdformat (read 3 bytes per sector via DMA and fill
1966      * the sector with the specified fill byte
1967      */
1968     fdctrl->data_state &= ~FD_STATE_FORMAT;
1969     fdctrl_stop_transfer(fdctrl, 0x00, 0x00, 0x00);
1970 }
1971 
1972 static void fdctrl_handle_specify(FDCtrl *fdctrl, int direction)
1973 {
1974     fdctrl->timer0 = (fdctrl->fifo[1] >> 4) & 0xF;
1975     fdctrl->timer1 = fdctrl->fifo[2] >> 1;
1976     if (fdctrl->fifo[2] & 1)
1977         fdctrl->dor &= ~FD_DOR_DMAEN;
1978     else
1979         fdctrl->dor |= FD_DOR_DMAEN;
1980     /* No result back */
1981     fdctrl_to_command_phase(fdctrl);
1982 }
1983 
1984 static void fdctrl_handle_sense_drive_status(FDCtrl *fdctrl, int direction)
1985 {
1986     FDrive *cur_drv;
1987 
1988     SET_CUR_DRV(fdctrl, fdctrl->fifo[1] & FD_DOR_SELMASK);
1989     cur_drv = get_cur_drv(fdctrl);
1990     cur_drv->head = (fdctrl->fifo[1] >> 2) & 1;
1991     /* 1 Byte status back */
1992     fdctrl->fifo[0] = (cur_drv->ro << 6) |
1993         (cur_drv->track == 0 ? 0x10 : 0x00) |
1994         (cur_drv->head << 2) |
1995         GET_CUR_DRV(fdctrl) |
1996         0x28;
1997     fdctrl_to_result_phase(fdctrl, 1);
1998 }
1999 
2000 static void fdctrl_handle_recalibrate(FDCtrl *fdctrl, int direction)
2001 {
2002     FDrive *cur_drv;
2003 
2004     SET_CUR_DRV(fdctrl, fdctrl->fifo[1] & FD_DOR_SELMASK);
2005     cur_drv = get_cur_drv(fdctrl);
2006     fd_recalibrate(cur_drv);
2007     fdctrl_to_command_phase(fdctrl);
2008     /* Raise Interrupt */
2009     fdctrl->status0 |= FD_SR0_SEEK;
2010     fdctrl_raise_irq(fdctrl);
2011 }
2012 
2013 static void fdctrl_handle_sense_interrupt_status(FDCtrl *fdctrl, int direction)
2014 {
2015     FDrive *cur_drv = get_cur_drv(fdctrl);
2016 
2017     if (fdctrl->reset_sensei > 0) {
2018         fdctrl->fifo[0] =
2019             FD_SR0_RDYCHG + FD_RESET_SENSEI_COUNT - fdctrl->reset_sensei;
2020         fdctrl->reset_sensei--;
2021     } else if (!(fdctrl->sra & FD_SRA_INTPEND)) {
2022         fdctrl->fifo[0] = FD_SR0_INVCMD;
2023         fdctrl_to_result_phase(fdctrl, 1);
2024         return;
2025     } else {
2026         fdctrl->fifo[0] =
2027                 (fdctrl->status0 & ~(FD_SR0_HEAD | FD_SR0_DS1 | FD_SR0_DS0))
2028                 | GET_CUR_DRV(fdctrl);
2029     }
2030 
2031     fdctrl->fifo[1] = cur_drv->track;
2032     fdctrl_to_result_phase(fdctrl, 2);
2033     fdctrl_reset_irq(fdctrl);
2034     fdctrl->status0 = FD_SR0_RDYCHG;
2035 }
2036 
2037 static void fdctrl_handle_seek(FDCtrl *fdctrl, int direction)
2038 {
2039     FDrive *cur_drv;
2040 
2041     SET_CUR_DRV(fdctrl, fdctrl->fifo[1] & FD_DOR_SELMASK);
2042     cur_drv = get_cur_drv(fdctrl);
2043     fdctrl_to_command_phase(fdctrl);
2044     /* The seek command just sends step pulses to the drive and doesn't care if
2045      * there is a medium inserted of if it's banging the head against the drive.
2046      */
2047     fd_seek(cur_drv, cur_drv->head, fdctrl->fifo[2], cur_drv->sect, 1);
2048     /* Raise Interrupt */
2049     fdctrl->status0 |= FD_SR0_SEEK;
2050     fdctrl_raise_irq(fdctrl);
2051 }
2052 
2053 static void fdctrl_handle_perpendicular_mode(FDCtrl *fdctrl, int direction)
2054 {
2055     FDrive *cur_drv = get_cur_drv(fdctrl);
2056 
2057     if (fdctrl->fifo[1] & 0x80)
2058         cur_drv->perpendicular = fdctrl->fifo[1] & 0x7;
2059     /* No result back */
2060     fdctrl_to_command_phase(fdctrl);
2061 }
2062 
2063 static void fdctrl_handle_configure(FDCtrl *fdctrl, int direction)
2064 {
2065     fdctrl->config = fdctrl->fifo[2];
2066     fdctrl->precomp_trk =  fdctrl->fifo[3];
2067     /* No result back */
2068     fdctrl_to_command_phase(fdctrl);
2069 }
2070 
2071 static void fdctrl_handle_powerdown_mode(FDCtrl *fdctrl, int direction)
2072 {
2073     fdctrl->pwrd = fdctrl->fifo[1];
2074     fdctrl->fifo[0] = fdctrl->fifo[1];
2075     fdctrl_to_result_phase(fdctrl, 1);
2076 }
2077 
2078 static void fdctrl_handle_option(FDCtrl *fdctrl, int direction)
2079 {
2080     /* No result back */
2081     fdctrl_to_command_phase(fdctrl);
2082 }
2083 
2084 static void fdctrl_handle_drive_specification_command(FDCtrl *fdctrl, int direction)
2085 {
2086     FDrive *cur_drv = get_cur_drv(fdctrl);
2087     uint32_t pos;
2088 
2089     pos = fdctrl->data_pos - 1;
2090     pos %= FD_SECTOR_LEN;
2091     if (fdctrl->fifo[pos] & 0x80) {
2092         /* Command parameters done */
2093         if (fdctrl->fifo[pos] & 0x40) {
2094             fdctrl->fifo[0] = fdctrl->fifo[1];
2095             fdctrl->fifo[2] = 0;
2096             fdctrl->fifo[3] = 0;
2097             fdctrl_to_result_phase(fdctrl, 4);
2098         } else {
2099             fdctrl_to_command_phase(fdctrl);
2100         }
2101     } else if (fdctrl->data_len > 7) {
2102         /* ERROR */
2103         fdctrl->fifo[0] = 0x80 |
2104             (cur_drv->head << 2) | GET_CUR_DRV(fdctrl);
2105         fdctrl_to_result_phase(fdctrl, 1);
2106     }
2107 }
2108 
2109 static void fdctrl_handle_relative_seek_in(FDCtrl *fdctrl, int direction)
2110 {
2111     FDrive *cur_drv;
2112 
2113     SET_CUR_DRV(fdctrl, fdctrl->fifo[1] & FD_DOR_SELMASK);
2114     cur_drv = get_cur_drv(fdctrl);
2115     if (fdctrl->fifo[2] + cur_drv->track >= cur_drv->max_track) {
2116         fd_seek(cur_drv, cur_drv->head, cur_drv->max_track - 1,
2117                 cur_drv->sect, 1);
2118     } else {
2119         fd_seek(cur_drv, cur_drv->head,
2120                 cur_drv->track + fdctrl->fifo[2], cur_drv->sect, 1);
2121     }
2122     fdctrl_to_command_phase(fdctrl);
2123     /* Raise Interrupt */
2124     fdctrl->status0 |= FD_SR0_SEEK;
2125     fdctrl_raise_irq(fdctrl);
2126 }
2127 
2128 static void fdctrl_handle_relative_seek_out(FDCtrl *fdctrl, int direction)
2129 {
2130     FDrive *cur_drv;
2131 
2132     SET_CUR_DRV(fdctrl, fdctrl->fifo[1] & FD_DOR_SELMASK);
2133     cur_drv = get_cur_drv(fdctrl);
2134     if (fdctrl->fifo[2] > cur_drv->track) {
2135         fd_seek(cur_drv, cur_drv->head, 0, cur_drv->sect, 1);
2136     } else {
2137         fd_seek(cur_drv, cur_drv->head,
2138                 cur_drv->track - fdctrl->fifo[2], cur_drv->sect, 1);
2139     }
2140     fdctrl_to_command_phase(fdctrl);
2141     /* Raise Interrupt */
2142     fdctrl->status0 |= FD_SR0_SEEK;
2143     fdctrl_raise_irq(fdctrl);
2144 }
2145 
2146 /*
2147  * Handlers for the execution phase of each command
2148  */
2149 typedef struct FDCtrlCommand {
2150     uint8_t value;
2151     uint8_t mask;
2152     const char* name;
2153     int parameters;
2154     void (*handler)(FDCtrl *fdctrl, int direction);
2155     int direction;
2156 } FDCtrlCommand;
2157 
2158 static const FDCtrlCommand handlers[] = {
2159     { FD_CMD_READ, 0x1f, "READ", 8, fdctrl_start_transfer, FD_DIR_READ },
2160     { FD_CMD_WRITE, 0x3f, "WRITE", 8, fdctrl_start_transfer, FD_DIR_WRITE },
2161     { FD_CMD_SEEK, 0xff, "SEEK", 2, fdctrl_handle_seek },
2162     { FD_CMD_SENSE_INTERRUPT_STATUS, 0xff, "SENSE INTERRUPT STATUS", 0, fdctrl_handle_sense_interrupt_status },
2163     { FD_CMD_RECALIBRATE, 0xff, "RECALIBRATE", 1, fdctrl_handle_recalibrate },
2164     { FD_CMD_FORMAT_TRACK, 0xbf, "FORMAT TRACK", 5, fdctrl_handle_format_track },
2165     { FD_CMD_READ_TRACK, 0xbf, "READ TRACK", 8, fdctrl_start_transfer, FD_DIR_READ },
2166     { FD_CMD_RESTORE, 0xff, "RESTORE", 17, fdctrl_handle_restore }, /* part of READ DELETED DATA */
2167     { FD_CMD_SAVE, 0xff, "SAVE", 0, fdctrl_handle_save }, /* part of READ DELETED DATA */
2168     { FD_CMD_READ_DELETED, 0x1f, "READ DELETED DATA", 8, fdctrl_start_transfer_del, FD_DIR_READ },
2169     { FD_CMD_SCAN_EQUAL, 0x1f, "SCAN EQUAL", 8, fdctrl_start_transfer, FD_DIR_SCANE },
2170     { FD_CMD_VERIFY, 0x1f, "VERIFY", 8, fdctrl_start_transfer, FD_DIR_VERIFY },
2171     { FD_CMD_SCAN_LOW_OR_EQUAL, 0x1f, "SCAN LOW OR EQUAL", 8, fdctrl_start_transfer, FD_DIR_SCANL },
2172     { FD_CMD_SCAN_HIGH_OR_EQUAL, 0x1f, "SCAN HIGH OR EQUAL", 8, fdctrl_start_transfer, FD_DIR_SCANH },
2173     { FD_CMD_WRITE_DELETED, 0x3f, "WRITE DELETED DATA", 8, fdctrl_start_transfer_del, FD_DIR_WRITE },
2174     { FD_CMD_READ_ID, 0xbf, "READ ID", 1, fdctrl_handle_readid },
2175     { FD_CMD_SPECIFY, 0xff, "SPECIFY", 2, fdctrl_handle_specify },
2176     { FD_CMD_SENSE_DRIVE_STATUS, 0xff, "SENSE DRIVE STATUS", 1, fdctrl_handle_sense_drive_status },
2177     { FD_CMD_PERPENDICULAR_MODE, 0xff, "PERPENDICULAR MODE", 1, fdctrl_handle_perpendicular_mode },
2178     { FD_CMD_CONFIGURE, 0xff, "CONFIGURE", 3, fdctrl_handle_configure },
2179     { FD_CMD_POWERDOWN_MODE, 0xff, "POWERDOWN MODE", 2, fdctrl_handle_powerdown_mode },
2180     { FD_CMD_OPTION, 0xff, "OPTION", 1, fdctrl_handle_option },
2181     { FD_CMD_DRIVE_SPECIFICATION_COMMAND, 0xff, "DRIVE SPECIFICATION COMMAND", 5, fdctrl_handle_drive_specification_command },
2182     { FD_CMD_RELATIVE_SEEK_OUT, 0xff, "RELATIVE SEEK OUT", 2, fdctrl_handle_relative_seek_out },
2183     { FD_CMD_FORMAT_AND_WRITE, 0xff, "FORMAT AND WRITE", 10, fdctrl_unimplemented },
2184     { FD_CMD_RELATIVE_SEEK_IN, 0xff, "RELATIVE SEEK IN", 2, fdctrl_handle_relative_seek_in },
2185     { FD_CMD_LOCK, 0x7f, "LOCK", 0, fdctrl_handle_lock },
2186     { FD_CMD_DUMPREG, 0xff, "DUMPREG", 0, fdctrl_handle_dumpreg },
2187     { FD_CMD_VERSION, 0xff, "VERSION", 0, fdctrl_handle_version },
2188     { FD_CMD_PART_ID, 0xff, "PART ID", 0, fdctrl_handle_partid },
2189     { FD_CMD_WRITE, 0x1f, "WRITE (BeOS)", 8, fdctrl_start_transfer, FD_DIR_WRITE }, /* not in specification ; BeOS 4.5 bug */
2190     { 0, 0, "unknown", 0, fdctrl_unimplemented }, /* default handler */
2191 };
2192 /* Associate command to an index in the 'handlers' array */
2193 static uint8_t command_to_handler[256];
2194 
2195 static const FDCtrlCommand *get_command(uint8_t cmd)
2196 {
2197     int idx;
2198 
2199     idx = command_to_handler[cmd];
2200     FLOPPY_DPRINTF("%s command\n", handlers[idx].name);
2201     return &handlers[idx];
2202 }
2203 
2204 static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t value)
2205 {
2206     FDrive *cur_drv;
2207     const FDCtrlCommand *cmd;
2208     uint32_t pos;
2209 
2210     /* Reset mode */
2211     if (!(fdctrl->dor & FD_DOR_nRESET)) {
2212         FLOPPY_DPRINTF("Floppy controller in RESET state !\n");
2213         return;
2214     }
2215     if (!(fdctrl->msr & FD_MSR_RQM) || (fdctrl->msr & FD_MSR_DIO)) {
2216         FLOPPY_DPRINTF("error: controller not ready for writing\n");
2217         return;
2218     }
2219     fdctrl->dsr &= ~FD_DSR_PWRDOWN;
2220 
2221     FLOPPY_DPRINTF("%s: %02x\n", __func__, value);
2222 
2223     /* If data_len spans multiple sectors, the current position in the FIFO
2224      * wraps around while fdctrl->data_pos is the real position in the whole
2225      * request. */
2226     pos = fdctrl->data_pos++;
2227     pos %= FD_SECTOR_LEN;
2228     fdctrl->fifo[pos] = value;
2229 
2230     if (fdctrl->data_pos == fdctrl->data_len) {
2231         fdctrl->msr &= ~FD_MSR_RQM;
2232     }
2233 
2234     switch (fdctrl->phase) {
2235     case FD_PHASE_EXECUTION:
2236         /* For DMA requests, RQM should be cleared during execution phase, so
2237          * we would have errored out above. */
2238         assert(fdctrl->msr & FD_MSR_NONDMA);
2239 
2240         /* FIFO data write */
2241         if (pos == FD_SECTOR_LEN - 1 ||
2242             fdctrl->data_pos == fdctrl->data_len) {
2243             cur_drv = get_cur_drv(fdctrl);
2244             if (blk_write(cur_drv->blk, fd_sector(cur_drv), fdctrl->fifo, 1)
2245                 < 0) {
2246                 FLOPPY_DPRINTF("error writing sector %d\n",
2247                                fd_sector(cur_drv));
2248                 break;
2249             }
2250             if (!fdctrl_seek_to_next_sect(fdctrl, cur_drv)) {
2251                 FLOPPY_DPRINTF("error seeking to next sector %d\n",
2252                                fd_sector(cur_drv));
2253                 break;
2254             }
2255         }
2256 
2257         /* Switch to result phase when done with the transfer */
2258         if (fdctrl->data_pos == fdctrl->data_len) {
2259             fdctrl_stop_transfer(fdctrl, 0x00, 0x00, 0x00);
2260         }
2261         break;
2262 
2263     case FD_PHASE_COMMAND:
2264         assert(!(fdctrl->msr & FD_MSR_NONDMA));
2265         assert(fdctrl->data_pos < FD_SECTOR_LEN);
2266 
2267         if (pos == 0) {
2268             /* The first byte specifies the command. Now we start reading
2269              * as many parameters as this command requires. */
2270             cmd = get_command(value);
2271             fdctrl->data_len = cmd->parameters + 1;
2272             if (cmd->parameters) {
2273                 fdctrl->msr |= FD_MSR_RQM;
2274             }
2275             fdctrl->msr |= FD_MSR_CMDBUSY;
2276         }
2277 
2278         if (fdctrl->data_pos == fdctrl->data_len) {
2279             /* We have all parameters now, execute the command */
2280             fdctrl->phase = FD_PHASE_EXECUTION;
2281 
2282             if (fdctrl->data_state & FD_STATE_FORMAT) {
2283                 fdctrl_format_sector(fdctrl);
2284                 break;
2285             }
2286 
2287             cmd = get_command(fdctrl->fifo[0]);
2288             FLOPPY_DPRINTF("Calling handler for '%s'\n", cmd->name);
2289             cmd->handler(fdctrl, cmd->direction);
2290         }
2291         break;
2292 
2293     case FD_PHASE_RESULT:
2294     default:
2295         abort();
2296     }
2297 }
2298 
2299 static void fdctrl_result_timer(void *opaque)
2300 {
2301     FDCtrl *fdctrl = opaque;
2302     FDrive *cur_drv = get_cur_drv(fdctrl);
2303 
2304     /* Pretend we are spinning.
2305      * This is needed for Coherent, which uses READ ID to check for
2306      * sector interleaving.
2307      */
2308     if (cur_drv->last_sect != 0) {
2309         cur_drv->sect = (cur_drv->sect % cur_drv->last_sect) + 1;
2310     }
2311     /* READ_ID can't automatically succeed! */
2312     if (fdctrl->check_media_rate &&
2313         (fdctrl->dsr & FD_DSR_DRATEMASK) != cur_drv->media_rate) {
2314         FLOPPY_DPRINTF("read id rate mismatch (fdc=%d, media=%d)\n",
2315                        fdctrl->dsr & FD_DSR_DRATEMASK, cur_drv->media_rate);
2316         fdctrl_stop_transfer(fdctrl, FD_SR0_ABNTERM, FD_SR1_MA, 0x00);
2317     } else {
2318         fdctrl_stop_transfer(fdctrl, 0x00, 0x00, 0x00);
2319     }
2320 }
2321 
2322 static void fdctrl_change_cb(void *opaque, bool load)
2323 {
2324     FDrive *drive = opaque;
2325 
2326     drive->media_changed = 1;
2327     drive->media_validated = false;
2328     fd_revalidate(drive);
2329 }
2330 
2331 static const BlockDevOps fdctrl_block_ops = {
2332     .change_media_cb = fdctrl_change_cb,
2333 };
2334 
2335 /* Init functions */
2336 static void fdctrl_connect_drives(FDCtrl *fdctrl, Error **errp)
2337 {
2338     unsigned int i;
2339     FDrive *drive;
2340 
2341     for (i = 0; i < MAX_FD; i++) {
2342         drive = &fdctrl->drives[i];
2343         drive->fdctrl = fdctrl;
2344 
2345         if (drive->blk) {
2346             if (blk_get_on_error(drive->blk, 0) != BLOCKDEV_ON_ERROR_ENOSPC) {
2347                 error_setg(errp, "fdc doesn't support drive option werror");
2348                 return;
2349             }
2350             if (blk_get_on_error(drive->blk, 1) != BLOCKDEV_ON_ERROR_REPORT) {
2351                 error_setg(errp, "fdc doesn't support drive option rerror");
2352                 return;
2353             }
2354         }
2355 
2356         fd_init(drive);
2357         if (drive->blk) {
2358             blk_set_dev_ops(drive->blk, &fdctrl_block_ops, drive);
2359             pick_drive_type(drive);
2360         }
2361         fd_revalidate(drive);
2362     }
2363 }
2364 
2365 ISADevice *fdctrl_init_isa(ISABus *bus, DriveInfo **fds)
2366 {
2367     DeviceState *dev;
2368     ISADevice *isadev;
2369 
2370     isadev = isa_try_create(bus, TYPE_ISA_FDC);
2371     if (!isadev) {
2372         return NULL;
2373     }
2374     dev = DEVICE(isadev);
2375 
2376     if (fds[0]) {
2377         qdev_prop_set_drive(dev, "driveA", blk_by_legacy_dinfo(fds[0]),
2378                             &error_fatal);
2379     }
2380     if (fds[1]) {
2381         qdev_prop_set_drive(dev, "driveB", blk_by_legacy_dinfo(fds[1]),
2382                             &error_fatal);
2383     }
2384     qdev_init_nofail(dev);
2385 
2386     return isadev;
2387 }
2388 
2389 void fdctrl_init_sysbus(qemu_irq irq, int dma_chann,
2390                         hwaddr mmio_base, DriveInfo **fds)
2391 {
2392     FDCtrl *fdctrl;
2393     DeviceState *dev;
2394     SysBusDevice *sbd;
2395     FDCtrlSysBus *sys;
2396 
2397     dev = qdev_create(NULL, "sysbus-fdc");
2398     sys = SYSBUS_FDC(dev);
2399     fdctrl = &sys->state;
2400     fdctrl->dma_chann = dma_chann; /* FIXME */
2401     if (fds[0]) {
2402         qdev_prop_set_drive(dev, "driveA", blk_by_legacy_dinfo(fds[0]),
2403                             &error_fatal);
2404     }
2405     if (fds[1]) {
2406         qdev_prop_set_drive(dev, "driveB", blk_by_legacy_dinfo(fds[1]),
2407                             &error_fatal);
2408     }
2409     qdev_init_nofail(dev);
2410     sbd = SYS_BUS_DEVICE(dev);
2411     sysbus_connect_irq(sbd, 0, irq);
2412     sysbus_mmio_map(sbd, 0, mmio_base);
2413 }
2414 
2415 void sun4m_fdctrl_init(qemu_irq irq, hwaddr io_base,
2416                        DriveInfo **fds, qemu_irq *fdc_tc)
2417 {
2418     DeviceState *dev;
2419     FDCtrlSysBus *sys;
2420 
2421     dev = qdev_create(NULL, "SUNW,fdtwo");
2422     if (fds[0]) {
2423         qdev_prop_set_drive(dev, "drive", blk_by_legacy_dinfo(fds[0]),
2424                             &error_fatal);
2425     }
2426     qdev_init_nofail(dev);
2427     sys = SYSBUS_FDC(dev);
2428     sysbus_connect_irq(SYS_BUS_DEVICE(sys), 0, irq);
2429     sysbus_mmio_map(SYS_BUS_DEVICE(sys), 0, io_base);
2430     *fdc_tc = qdev_get_gpio_in(dev, 0);
2431 }
2432 
2433 static void fdctrl_realize_common(FDCtrl *fdctrl, Error **errp)
2434 {
2435     int i, j;
2436     static int command_tables_inited = 0;
2437 
2438     if (fdctrl->fallback == FLOPPY_DRIVE_TYPE_AUTO) {
2439         error_setg(errp, "Cannot choose a fallback FDrive type of 'auto'");
2440     }
2441 
2442     /* Fill 'command_to_handler' lookup table */
2443     if (!command_tables_inited) {
2444         command_tables_inited = 1;
2445         for (i = ARRAY_SIZE(handlers) - 1; i >= 0; i--) {
2446             for (j = 0; j < sizeof(command_to_handler); j++) {
2447                 if ((j & handlers[i].mask) == handlers[i].value) {
2448                     command_to_handler[j] = i;
2449                 }
2450             }
2451         }
2452     }
2453 
2454     FLOPPY_DPRINTF("init controller\n");
2455     fdctrl->fifo = qemu_memalign(512, FD_SECTOR_LEN);
2456     fdctrl->fifo_size = 512;
2457     fdctrl->result_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
2458                                              fdctrl_result_timer, fdctrl);
2459 
2460     fdctrl->version = 0x90; /* Intel 82078 controller */
2461     fdctrl->config = FD_CONFIG_EIS | FD_CONFIG_EFIFO; /* Implicit seek, polling & FIFO enabled */
2462     fdctrl->num_floppies = MAX_FD;
2463 
2464     if (fdctrl->dma_chann != -1) {
2465         IsaDmaClass *k;
2466         assert(fdctrl->dma);
2467         k = ISADMA_GET_CLASS(fdctrl->dma);
2468         k->register_channel(fdctrl->dma, fdctrl->dma_chann,
2469                             &fdctrl_transfer_handler, fdctrl);
2470     }
2471     fdctrl_connect_drives(fdctrl, errp);
2472 }
2473 
2474 static const MemoryRegionPortio fdc_portio_list[] = {
2475     { 1, 5, 1, .read = fdctrl_read, .write = fdctrl_write },
2476     { 7, 1, 1, .read = fdctrl_read, .write = fdctrl_write },
2477     PORTIO_END_OF_LIST(),
2478 };
2479 
2480 static void isabus_fdc_realize(DeviceState *dev, Error **errp)
2481 {
2482     ISADevice *isadev = ISA_DEVICE(dev);
2483     FDCtrlISABus *isa = ISA_FDC(dev);
2484     FDCtrl *fdctrl = &isa->state;
2485     Error *err = NULL;
2486 
2487     isa_register_portio_list(isadev, isa->iobase, fdc_portio_list, fdctrl,
2488                              "fdc");
2489 
2490     isa_init_irq(isadev, &fdctrl->irq, isa->irq);
2491     fdctrl->dma_chann = isa->dma;
2492     if (fdctrl->dma_chann != -1) {
2493         fdctrl->dma = isa_get_dma(isa_bus_from_device(isadev), isa->dma);
2494         assert(fdctrl->dma);
2495     }
2496 
2497     qdev_set_legacy_instance_id(dev, isa->iobase, 2);
2498     fdctrl_realize_common(fdctrl, &err);
2499     if (err != NULL) {
2500         error_propagate(errp, err);
2501         return;
2502     }
2503 }
2504 
2505 static void sysbus_fdc_initfn(Object *obj)
2506 {
2507     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
2508     FDCtrlSysBus *sys = SYSBUS_FDC(obj);
2509     FDCtrl *fdctrl = &sys->state;
2510 
2511     fdctrl->dma_chann = -1;
2512 
2513     memory_region_init_io(&fdctrl->iomem, obj, &fdctrl_mem_ops, fdctrl,
2514                           "fdc", 0x08);
2515     sysbus_init_mmio(sbd, &fdctrl->iomem);
2516 }
2517 
2518 static void sun4m_fdc_initfn(Object *obj)
2519 {
2520     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
2521     FDCtrlSysBus *sys = SYSBUS_FDC(obj);
2522     FDCtrl *fdctrl = &sys->state;
2523 
2524     fdctrl->dma_chann = -1;
2525 
2526     memory_region_init_io(&fdctrl->iomem, obj, &fdctrl_mem_strict_ops,
2527                           fdctrl, "fdctrl", 0x08);
2528     sysbus_init_mmio(sbd, &fdctrl->iomem);
2529 }
2530 
2531 static void sysbus_fdc_common_initfn(Object *obj)
2532 {
2533     DeviceState *dev = DEVICE(obj);
2534     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
2535     FDCtrlSysBus *sys = SYSBUS_FDC(obj);
2536     FDCtrl *fdctrl = &sys->state;
2537 
2538     qdev_set_legacy_instance_id(dev, 0 /* io */, 2); /* FIXME */
2539 
2540     sysbus_init_irq(sbd, &fdctrl->irq);
2541     qdev_init_gpio_in(dev, fdctrl_handle_tc, 1);
2542 }
2543 
2544 static void sysbus_fdc_common_realize(DeviceState *dev, Error **errp)
2545 {
2546     FDCtrlSysBus *sys = SYSBUS_FDC(dev);
2547     FDCtrl *fdctrl = &sys->state;
2548 
2549     fdctrl_realize_common(fdctrl, errp);
2550 }
2551 
2552 FloppyDriveType isa_fdc_get_drive_type(ISADevice *fdc, int i)
2553 {
2554     FDCtrlISABus *isa = ISA_FDC(fdc);
2555 
2556     return isa->state.drives[i].drive;
2557 }
2558 
2559 static const VMStateDescription vmstate_isa_fdc ={
2560     .name = "fdc",
2561     .version_id = 2,
2562     .minimum_version_id = 2,
2563     .fields = (VMStateField[]) {
2564         VMSTATE_STRUCT(state, FDCtrlISABus, 0, vmstate_fdc, FDCtrl),
2565         VMSTATE_END_OF_LIST()
2566     }
2567 };
2568 
2569 static Property isa_fdc_properties[] = {
2570     DEFINE_PROP_UINT32("iobase", FDCtrlISABus, iobase, 0x3f0),
2571     DEFINE_PROP_UINT32("irq", FDCtrlISABus, irq, 6),
2572     DEFINE_PROP_UINT32("dma", FDCtrlISABus, dma, 2),
2573     DEFINE_PROP_DRIVE("driveA", FDCtrlISABus, state.drives[0].blk),
2574     DEFINE_PROP_DRIVE("driveB", FDCtrlISABus, state.drives[1].blk),
2575     DEFINE_PROP_BIT("check_media_rate", FDCtrlISABus, state.check_media_rate,
2576                     0, true),
2577     DEFINE_PROP_DEFAULT("fdtypeA", FDCtrlISABus, state.drives[0].drive,
2578                         FLOPPY_DRIVE_TYPE_AUTO, qdev_prop_fdc_drive_type,
2579                         FloppyDriveType),
2580     DEFINE_PROP_DEFAULT("fdtypeB", FDCtrlISABus, state.drives[1].drive,
2581                         FLOPPY_DRIVE_TYPE_AUTO, qdev_prop_fdc_drive_type,
2582                         FloppyDriveType),
2583     DEFINE_PROP_DEFAULT("fallback", FDCtrlISABus, state.fallback,
2584                         FLOPPY_DRIVE_TYPE_288, qdev_prop_fdc_drive_type,
2585                         FloppyDriveType),
2586     DEFINE_PROP_END_OF_LIST(),
2587 };
2588 
2589 static void isabus_fdc_class_init(ObjectClass *klass, void *data)
2590 {
2591     DeviceClass *dc = DEVICE_CLASS(klass);
2592 
2593     dc->realize = isabus_fdc_realize;
2594     dc->fw_name = "fdc";
2595     dc->reset = fdctrl_external_reset_isa;
2596     dc->vmsd = &vmstate_isa_fdc;
2597     dc->props = isa_fdc_properties;
2598     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
2599 }
2600 
2601 static void isabus_fdc_instance_init(Object *obj)
2602 {
2603     FDCtrlISABus *isa = ISA_FDC(obj);
2604 
2605     device_add_bootindex_property(obj, &isa->bootindexA,
2606                                   "bootindexA", "/floppy@0",
2607                                   DEVICE(obj), NULL);
2608     device_add_bootindex_property(obj, &isa->bootindexB,
2609                                   "bootindexB", "/floppy@1",
2610                                   DEVICE(obj), NULL);
2611 }
2612 
2613 static const TypeInfo isa_fdc_info = {
2614     .name          = TYPE_ISA_FDC,
2615     .parent        = TYPE_ISA_DEVICE,
2616     .instance_size = sizeof(FDCtrlISABus),
2617     .class_init    = isabus_fdc_class_init,
2618     .instance_init = isabus_fdc_instance_init,
2619 };
2620 
2621 static const VMStateDescription vmstate_sysbus_fdc ={
2622     .name = "fdc",
2623     .version_id = 2,
2624     .minimum_version_id = 2,
2625     .fields = (VMStateField[]) {
2626         VMSTATE_STRUCT(state, FDCtrlSysBus, 0, vmstate_fdc, FDCtrl),
2627         VMSTATE_END_OF_LIST()
2628     }
2629 };
2630 
2631 static Property sysbus_fdc_properties[] = {
2632     DEFINE_PROP_DRIVE("driveA", FDCtrlSysBus, state.drives[0].blk),
2633     DEFINE_PROP_DRIVE("driveB", FDCtrlSysBus, state.drives[1].blk),
2634     DEFINE_PROP_DEFAULT("fdtypeA", FDCtrlSysBus, state.drives[0].drive,
2635                         FLOPPY_DRIVE_TYPE_AUTO, qdev_prop_fdc_drive_type,
2636                         FloppyDriveType),
2637     DEFINE_PROP_DEFAULT("fdtypeB", FDCtrlSysBus, state.drives[1].drive,
2638                         FLOPPY_DRIVE_TYPE_AUTO, qdev_prop_fdc_drive_type,
2639                         FloppyDriveType),
2640     DEFINE_PROP_DEFAULT("fallback", FDCtrlISABus, state.fallback,
2641                         FLOPPY_DRIVE_TYPE_144, qdev_prop_fdc_drive_type,
2642                         FloppyDriveType),
2643     DEFINE_PROP_END_OF_LIST(),
2644 };
2645 
2646 static void sysbus_fdc_class_init(ObjectClass *klass, void *data)
2647 {
2648     DeviceClass *dc = DEVICE_CLASS(klass);
2649 
2650     dc->props = sysbus_fdc_properties;
2651     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
2652 }
2653 
2654 static const TypeInfo sysbus_fdc_info = {
2655     .name          = "sysbus-fdc",
2656     .parent        = TYPE_SYSBUS_FDC,
2657     .instance_init = sysbus_fdc_initfn,
2658     .class_init    = sysbus_fdc_class_init,
2659 };
2660 
2661 static Property sun4m_fdc_properties[] = {
2662     DEFINE_PROP_DRIVE("drive", FDCtrlSysBus, state.drives[0].blk),
2663     DEFINE_PROP_DEFAULT("fdtype", FDCtrlSysBus, state.drives[0].drive,
2664                         FLOPPY_DRIVE_TYPE_AUTO, qdev_prop_fdc_drive_type,
2665                         FloppyDriveType),
2666     DEFINE_PROP_DEFAULT("fallback", FDCtrlISABus, state.fallback,
2667                         FLOPPY_DRIVE_TYPE_144, qdev_prop_fdc_drive_type,
2668                         FloppyDriveType),
2669     DEFINE_PROP_END_OF_LIST(),
2670 };
2671 
2672 static void sun4m_fdc_class_init(ObjectClass *klass, void *data)
2673 {
2674     DeviceClass *dc = DEVICE_CLASS(klass);
2675 
2676     dc->props = sun4m_fdc_properties;
2677     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
2678 }
2679 
2680 static const TypeInfo sun4m_fdc_info = {
2681     .name          = "SUNW,fdtwo",
2682     .parent        = TYPE_SYSBUS_FDC,
2683     .instance_init = sun4m_fdc_initfn,
2684     .class_init    = sun4m_fdc_class_init,
2685 };
2686 
2687 static void sysbus_fdc_common_class_init(ObjectClass *klass, void *data)
2688 {
2689     DeviceClass *dc = DEVICE_CLASS(klass);
2690 
2691     dc->realize = sysbus_fdc_common_realize;
2692     dc->reset = fdctrl_external_reset_sysbus;
2693     dc->vmsd = &vmstate_sysbus_fdc;
2694 }
2695 
2696 static const TypeInfo sysbus_fdc_type_info = {
2697     .name          = TYPE_SYSBUS_FDC,
2698     .parent        = TYPE_SYS_BUS_DEVICE,
2699     .instance_size = sizeof(FDCtrlSysBus),
2700     .instance_init = sysbus_fdc_common_initfn,
2701     .abstract      = true,
2702     .class_init    = sysbus_fdc_common_class_init,
2703 };
2704 
2705 static void fdc_register_types(void)
2706 {
2707     type_register_static(&isa_fdc_info);
2708     type_register_static(&sysbus_fdc_type_info);
2709     type_register_static(&sysbus_fdc_info);
2710     type_register_static(&sun4m_fdc_info);
2711 }
2712 
2713 type_init(fdc_register_types)
2714