1/*  This file is part of the program psim.
2
3    Copyright (C) 1994-1997, Andrew Cagney <cagney@highland.com.au>
4
5    This program is free software; you can redistribute it and/or modify
6    it under the terms of the GNU General Public License as published by
7    the Free Software Foundation; either version 3 of the License, or
8    (at your option) any later version.
9
10    This program is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13    GNU General Public License for more details.
14
15    You should have received a copy of the GNU General Public License
16    along with this program; if not, see <http://www.gnu.org/licenses/>.
17
18    */
19
20
21#ifndef _HW_DISK_C_
22#define _HW_DISK_C_
23
24#include "device_table.h"
25
26#include "pk.h"
27
28#include <stdio.h>
29
30#ifdef HAVE_UNISTD_H
31#include <unistd.h>
32#endif
33
34#ifndef	SEEK_SET
35#define	SEEK_SET 0
36#endif
37
38/* DEVICE
39
40
41   cdrom - read-only removable mass storage device
42
43   disk - mass storage device
44
45   floppy - removable mass storage device
46
47
48   DESCRIPTION
49
50
51   Mass storage devices such as a hard-disk or cdrom-drive are not
52   normally directly connected to the processor.  Instead, these
53   devices are attached to a logical bus, such as SCSI or IDE, and
54   then a controller of that bus is made accessible to the processor.
55
56   Reflecting this, within a device tree, mass storage devices such as
57   a <<cdrom>>, <<disk>> or <<floppy>> are created as children of of a
58   logical bus controller node (such as a SCSI or IDE interface).
59   That controller, in turn, would be made the child of a physical bus
60   node that is directly accessible to the processor.
61
62   The above mass storage devices provide two interfaces - a logical
63   and a physical.
64
65   At the physical level the <<device_io_...>> functions can be used
66   perform reads and writes of the raw media.  The address being
67   interpreted as an offset from the start of the disk.
68
69   At the logical level, it is possible to create an instance of the
70   disk that provides access to any of the physical media, a disk
71   partition, or even a file within a partition.  The <<disk-label>>
72   package, which implements this functionality, is described
73   elsewhere.  Both the Open Firmware and Moto BUG rom emulations
74   support this interface.
75
76   Block devices such as the <<floppy>> and <<cdrom>> have removable
77   media.  At the programmer level, the media can be changed using the
78   <<change_media>> ioctl.  From within GDB, a <<change-media>>
79   operation can be initated by using the command.
80
81   |	(gdb)  sim
82
83
84   PROPERTIES
85
86
87   file = <file-name>  (required)
88
89   The name of the file that contains an image of the disk.  For
90   <<disk>> and <<floppy>> devices, the image will be opened for both
91   reading and writing.  Multiple image files may be specified, the
92   second and later files being opened when <<change-media>> (with a
93   NULL file name) being specified.
94
95
96   block-size = <nr-bytes>  (optional)
97
98   The value is returned by the block-size method.  The default value
99   is 512 bytes.
100
101
102   max-transfer = <nr-bytes>  (optional)
103
104   The value is returned by the max-transfer method. The default value
105   is 512 bytes.
106
107
108   #blocks = <nr-blocks>  (optional)
109
110   The value is returned by the #blocks method.  If no value is
111   present then -1 is returned.
112
113
114   read-only = <anything>  (optional)
115
116   If this property is present, the disk file image is always opened
117   read-only.
118
119   EXAMPLES
120
121
122   Enable tracing
123
124   | $  psim -t 'disk-device' \
125
126
127   Add a CDROM and disk to an IDE bus.  Specify the host operating
128   system's cd drive as the CD-ROM image.
129
130   |    -o '/pci/ide/disk@0/file "disk-image' \
131   |    -o '/pci/ide/cdrom@1/file "/dev/cd0a' \
132
133
134   As part of the code implementing a logical bus device (for instance
135   the IDE controller), locate the CDROM device and then read block
136   47.
137
138   |  device *cdrom = device_tree_find_device(me, "cdrom");
139   |  char block[512];
140   |  device_io_read_buffer(cdrom, buf, 0,
141                            0, 47 * sizeof(block), // space, address
142                            sizeof(block), NULL, 0);
143
144
145   Use the device instance interface to read block 47 of the file
146   called <<netbsd.elf>> on the disks default partition.  Similar code
147   would be used in an operating systems pre-boot loader.
148
149   |  device_instance *netbsd =
150   |    device_create_instance(root, "/pci/ide/disk:,\netbsd.elf");
151   |  char block[512];
152   |  device_instance_seek(netbsd,  0, 47 * sizeof(block));
153   |  device_instance_read(netbsd, block, sizeof(block));
154
155
156   BUGS
157
158
159   The block device specification includes mechanisms for determining
160   the physical device characteristics - such as the disks size.
161   Currently this mechanism is not implemented.
162
163   The functionality of this device (in particular the device instance
164   interface) depends on the implementation of <<disk-label>> package.
165   That package may not be fully implemented.
166
167   The disk does not know its size.  Hence it relies on the failure of
168   fread(), fwrite() and fseek() calls to detect errors.
169
170   The disk size is limited by the addressable range covered by
171   unsigned_word (addr).  An extension would be to instead use the
172   concatenated value space:addr.
173
174   The method #blocks should `stat' the disk to determine the number
175   of blocks if there is no #blocks property.
176
177   It would appear that OpenFirmware does not define a client call for
178   changing (ejecting) the media of a device.
179
180   */
181
182typedef struct _hw_disk_device {
183  int name_index;
184  int nr_names;
185  char *name;
186  int read_only;
187  /*  unsigned_word size; */
188  FILE *image;
189} hw_disk_device;
190
191typedef struct _hw_disk_instance {
192  unsigned_word pos;
193  hw_disk_device *disk;
194} hw_disk_instance;
195
196
197static void
198open_disk_image(device *me,
199		hw_disk_device *disk,
200		const char *name)
201{
202  if (disk->image != NULL)
203    fclose(disk->image);
204  if (disk->name != NULL)
205    free(disk->name);
206  disk->name = strdup(name);
207  disk->image = fopen(disk->name, disk->read_only ? "r" : "r+");
208  if (disk->image == NULL) {
209    perror(device_name(me));
210    device_error(me, "open %s failed\n", disk->name);
211  }
212
213  DTRACE(disk, ("image %s (%s)\n",
214                disk->name,
215                (disk->read_only ? "read-only" : "read-write")));
216}
217
218static void
219hw_disk_init_address(device *me)
220{
221  hw_disk_device *disk = device_data(me);
222  unsigned_word address;
223  int space;
224  const char *name;
225
226  /* attach to the parent. Since the bus is logical, attach using just
227     the unit-address (size must be zero) */
228  device_address_to_attach_address(device_parent(me), device_unit_address(me),
229				   &space, &address, me);
230  device_attach_address(device_parent(me), attach_callback,
231			space, address, 0/*size*/, access_read_write_exec,
232			me);
233
234  /* Tell the world we are a disk.  */
235  device_add_string_property(me, "device_type", "block");
236
237  /* get the name of the file specifying the disk image */
238  disk->name_index = 0;
239  disk->nr_names = device_find_string_array_property(me, "file",
240						     disk->name_index, &name);
241  if (!disk->nr_names)
242    device_error(me, "invalid file property");
243
244  /* is it a RO device? */
245  disk->read_only =
246    (strcmp(device_name(me), "disk") != 0
247     && strcmp(device_name(me), "floppy") != 0
248     && device_find_property(me, "read-only") == NULL);
249
250  /* now open it */
251  open_disk_image(me, disk, name);
252}
253
254static int
255hw_disk_ioctl(device *me,
256	      cpu *processor,
257	      unsigned_word cia,
258	      device_ioctl_request request,
259	      va_list ap)
260{
261  switch (request) {
262  case device_ioctl_change_media:
263    {
264      hw_disk_device *disk = device_data(me);
265      const char *name = va_arg(ap, const char *);
266      if (name != NULL) {
267	disk->name_index = -1;
268      }
269      else {
270	disk->name_index = (disk->name_index + 1) % disk->nr_names;
271	if (!device_find_string_array_property(me, "file",
272					       disk->name_index, &name))
273	  device_error(me, "invalid file property");
274      }
275      open_disk_image(me, disk, name);
276    }
277    break;
278  default:
279    device_error(me, "insupported ioctl request");
280    break;
281  }
282  return 0;
283}
284
285
286
287
288
289static unsigned
290hw_disk_io_read_buffer(device *me,
291		       void *dest,
292		       int space,
293		       unsigned_word addr,
294		       unsigned nr_bytes,
295		       cpu *processor,
296		       unsigned_word cia)
297{
298  hw_disk_device *disk = device_data(me);
299  unsigned nr_bytes_read;
300  if (space != 0)
301    device_error(me, "read - extended disk addressing unimplemented");
302  if (nr_bytes == 0)
303    nr_bytes_read = 0;
304  else if (fseek(disk->image, addr, SEEK_SET) < 0)
305    nr_bytes_read = 0;
306  else if (fread(dest, nr_bytes, 1, disk->image) != 1)
307    nr_bytes_read = 0;
308  else
309    nr_bytes_read = nr_bytes;
310  DTRACE(disk, ("io-read - address 0x%lx, nr-bytes-read %d, requested %d\n",
311                (unsigned long) addr, (int)nr_bytes_read, (int)nr_bytes));
312  return nr_bytes_read;
313}
314
315
316static unsigned
317hw_disk_io_write_buffer(device *me,
318			const void *source,
319			int space,
320			unsigned_word addr,
321			unsigned nr_bytes,
322			cpu *processor,
323			unsigned_word cia)
324{
325  hw_disk_device *disk = device_data(me);
326  unsigned nr_bytes_written;
327  if (space != 0)
328    device_error(me, "write - extended disk addressing unimplemented");
329  if (disk->read_only)
330    nr_bytes_written = 0;
331  else if (nr_bytes == 0)
332    nr_bytes_written = 0;
333  else if (fseek(disk->image, addr, SEEK_SET) < 0)
334    nr_bytes_written = 0;
335  else if (fwrite(source, nr_bytes, 1, disk->image) != 1)
336    nr_bytes_written = 0;
337  else
338    nr_bytes_written = nr_bytes;
339  DTRACE(disk, ("io-write - address 0x%lx, nr-bytes-written %d, requested %d\n",
340                (unsigned long) addr, (int)nr_bytes_written, (int)nr_bytes));
341  return nr_bytes_written;
342}
343
344
345/* instances of the hw_disk device */
346
347static void
348hw_disk_instance_delete(device_instance *instance)
349{
350  hw_disk_instance *data = device_instance_data(instance);
351  DITRACE(disk, ("delete - instance=%ld\n",
352		 (unsigned long)device_instance_to_external(instance)));
353  free(data);
354}
355
356static int
357hw_disk_instance_read(device_instance *instance,
358		      void *buf,
359		      unsigned_word len)
360{
361  hw_disk_instance *data = device_instance_data(instance);
362  DITRACE(disk, ("read - instance=%ld len=%ld\n",
363		 (unsigned long)device_instance_to_external(instance),
364		 (long)len));
365  if ((data->pos + len) < data->pos)
366    return -1; /* overflow */
367  if (fseek(data->disk->image, data->pos, SEEK_SET) < 0)
368    return -1;
369  if (fread(buf, len, 1, data->disk->image) != 1)
370    return -1;
371  data->pos = ftell(data->disk->image);
372  return len;
373}
374
375static int
376hw_disk_instance_write(device_instance *instance,
377		       const void *buf,
378		       unsigned_word len)
379{
380  hw_disk_instance *data = device_instance_data(instance);
381  DITRACE(disk, ("write - instance=%ld len=%ld\n",
382		 (unsigned long)device_instance_to_external(instance),
383		 (long)len));
384  if ((data->pos + len) < data->pos)
385    return -1; /* overflow */
386  if (data->disk->read_only)
387    return -1;
388  if (fseek(data->disk->image, data->pos, SEEK_SET) < 0)
389    return -1;
390  if (fwrite(buf, len, 1, data->disk->image) != 1)
391    return -1;
392  data->pos = ftell(data->disk->image);
393  return len;
394}
395
396static int
397hw_disk_instance_seek(device_instance *instance,
398		      unsigned_word pos_hi,
399		      unsigned_word pos_lo)
400{
401  hw_disk_instance *data = device_instance_data(instance);
402  if (pos_hi != 0)
403    device_error(device_instance_device(instance),
404		 "seek - extended addressing unimplemented");
405  DITRACE(disk, ("seek - instance=%ld pos_hi=%ld pos_lo=%ld\n",
406		 (unsigned long)device_instance_to_external(instance),
407		 (long)pos_hi, (long)pos_lo));
408  data->pos = pos_lo;
409  return 0;
410}
411
412static int
413hw_disk_max_transfer(device_instance *instance,
414		     int n_stack_args,
415		     unsigned32 stack_args[/*n_stack_args*/],
416		     int n_stack_returns,
417		     unsigned32 stack_returns[/*n_stack_returns*/])
418{
419  device *me = device_instance_device(instance);
420  if ((n_stack_args != 0)
421      || (n_stack_returns != 1)) {
422    device_error(me, "Incorrect number of arguments for max-transfer method\n");
423    return -1;
424  }
425  else {
426    unsigned_cell max_transfer;
427    if (device_find_property(me, "max-transfer"))
428      max_transfer = device_find_integer_property(me, "max-transfer");
429    else
430      max_transfer = 512;
431    DITRACE(disk, ("max-transfer - instance=%ld max-transfer=%ld\n",
432		   (unsigned long)device_instance_to_external(instance),
433		   (long int)max_transfer));
434    stack_returns[0] = max_transfer;
435    return 0;
436  }
437}
438
439static int
440hw_disk_block_size(device_instance *instance,
441		   int n_stack_args,
442		   unsigned32 stack_args[/*n_stack_args*/],
443		   int n_stack_returns,
444		   unsigned32 stack_returns[/*n_stack_returns*/])
445{
446  device *me = device_instance_device(instance);
447  if ((n_stack_args != 0)
448      || (n_stack_returns != 1)) {
449    device_error(me, "Incorrect number of arguments for block-size method\n");
450    return -1;
451  }
452  else {
453    unsigned_cell block_size;
454    if (device_find_property(me, "block-size"))
455      block_size = device_find_integer_property(me, "block-size");
456    else
457      block_size = 512;
458    DITRACE(disk, ("block-size - instance=%ld block-size=%ld\n",
459		   (unsigned long)device_instance_to_external(instance),
460		   (long int)block_size));
461    stack_returns[0] = block_size;
462    return 0;
463  }
464}
465
466static int
467hw_disk_nr_blocks(device_instance *instance,
468		  int n_stack_args,
469		  unsigned32 stack_args[/*n_stack_args*/],
470		  int n_stack_returns,
471		  unsigned32 stack_returns[/*n_stack_returns*/])
472{
473  device *me = device_instance_device(instance);
474  if ((n_stack_args != 0)
475      || (n_stack_returns != 1)) {
476    device_error(me, "Incorrect number of arguments for block-size method\n");
477    return -1;
478  }
479  else {
480    unsigned_word nr_blocks;
481    if (device_find_property(me, "#blocks"))
482      nr_blocks = device_find_integer_property(me, "#blocks");
483    else
484      nr_blocks = -1;
485    DITRACE(disk, ("#blocks - instance=%ld #blocks=%ld\n",
486		   (unsigned long)device_instance_to_external(instance),
487		   (long int)nr_blocks));
488    stack_returns[0] = nr_blocks;
489    return 0;
490  }
491}
492
493static device_instance_methods hw_disk_instance_methods[] = {
494  { "max-transfer", hw_disk_max_transfer },
495  { "block-size", hw_disk_block_size },
496  { "#blocks", hw_disk_nr_blocks },
497  { NULL, },
498};
499
500static const device_instance_callbacks hw_disk_instance_callbacks = {
501  hw_disk_instance_delete,
502  hw_disk_instance_read,
503  hw_disk_instance_write,
504  hw_disk_instance_seek,
505  hw_disk_instance_methods,
506};
507
508static device_instance *
509hw_disk_create_instance(device *me,
510			const char *path,
511			const char *args)
512{
513  device_instance *instance;
514  hw_disk_device *disk = device_data(me);
515  hw_disk_instance *data = ZALLOC(hw_disk_instance);
516  data->disk = disk;
517  data->pos = 0;
518  instance = device_create_instance_from(me, NULL,
519					 data,
520					 path, args,
521					 &hw_disk_instance_callbacks);
522  DITRACE(disk, ("create - path=%s(%s) instance=%ld\n",
523		 path, args,
524		 (unsigned long)device_instance_to_external(instance)));
525  return pk_disklabel_create_instance(instance, args);
526}
527
528static device_callbacks const hw_disk_callbacks = {
529  { hw_disk_init_address, NULL },
530  { NULL, }, /* address */
531  { hw_disk_io_read_buffer,
532      hw_disk_io_write_buffer, },
533  { NULL, }, /* DMA */
534  { NULL, }, /* interrupt */
535  { NULL, }, /* unit */
536  hw_disk_create_instance,
537  hw_disk_ioctl,
538};
539
540
541static void *
542hw_disk_create(const char *name,
543	       const device_unit *unit_address,
544	       const char *args)
545{
546  /* create the descriptor */
547  hw_disk_device *hw_disk = ZALLOC(hw_disk_device);
548  return hw_disk;
549}
550
551
552const device_descriptor hw_disk_device_descriptor[] = {
553  { "disk", hw_disk_create, &hw_disk_callbacks },
554  { "cdrom", hw_disk_create, &hw_disk_callbacks },
555  { "floppy", hw_disk_create, &hw_disk_callbacks },
556  { NULL },
557};
558
559#endif /* _HW_DISK_C_ */
560