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e0709f50 AC |
1 | /* dv-nvram.c -- Generic driver for a non volatile ram (battery saved) |
2 | Copyright (C) 1999, 2000 Free Software Foundation, Inc. | |
3 | Written by Stephane Carrez (stcarrez@worldnet.fr) | |
4 | (From a driver model Contributed by Cygnus Solutions.) | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program; if not, write to the Free Software | |
18 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
19 | ||
20 | */ | |
21 | ||
22 | ||
23 | #include "sim-main.h" | |
24 | #include "hw-main.h" | |
25 | #include "sim-assert.h" | |
26 | ||
27 | #include <unistd.h> | |
28 | #include <fcntl.h> | |
29 | #include <errno.h> | |
30 | ||
31 | ||
32 | /* DEVICE | |
33 | ||
34 | nvram - Non Volatile Ram | |
35 | ||
36 | ||
37 | DESCRIPTION | |
38 | ||
39 | Implements a generic battery saved CMOS ram. This ram device does | |
40 | not contain any realtime clock and does not generate any interrupt. | |
41 | The ram content is loaded from a file and saved when it is changed. | |
42 | It is intended to be generic. | |
43 | ||
44 | ||
45 | PROPERTIES | |
46 | ||
e0709f50 AC |
47 | reg <base> <length> |
48 | ||
49 | Base and size of the non-volatile ram bank. | |
50 | ||
51 | file <path> | |
52 | ||
53 | Path where the memory must be saved or loaded when we start. | |
54 | ||
55 | mode {map | save-modified | save-all} | |
56 | ||
57 | Controls how to load and save the memory content. | |
58 | ||
59 | map The file is mapped in memory | |
60 | save-modified The simulator keeps an open file descriptor to | |
61 | the file and saves portion of memory which are | |
62 | modified. | |
63 | save-all The simulator saves the complete memory each time | |
64 | it's modified (it does not keep an open file | |
65 | descriptor). | |
66 | ||
67 | ||
68 | PORTS | |
69 | ||
70 | None. | |
71 | ||
72 | ||
73 | NOTES | |
74 | ||
75 | This device is independent of the Motorola 68hc11. | |
76 | ||
77 | */ | |
78 | ||
79 | ||
80 | ||
81 | /* static functions */ | |
82 | ||
83 | /* Control of how to access the ram and save its content. */ | |
84 | ||
85 | enum nvram_mode | |
86 | { | |
87 | /* Save the complete ram block each time it's changed. | |
88 | We don't keep an open file descriptor. This should be | |
89 | ok for small memory banks. */ | |
90 | NVRAM_SAVE_ALL, | |
91 | ||
92 | /* Save only the memory bytes which are modified. | |
93 | This mode means that we have to keep an open file | |
94 | descriptor (O_RDWR). It's good for middle sized memory banks. */ | |
95 | NVRAM_SAVE_MODIFIED, | |
96 | ||
97 | /* Map file in memory (not yet implemented). | |
98 | This mode is suitable for large memory banks. We don't allocate | |
99 | a buffer to represent the ram, instead it's mapped in memory | |
100 | with mmap. */ | |
101 | NVRAM_MAP_FILE | |
102 | }; | |
103 | ||
104 | struct nvram | |
105 | { | |
106 | address_word base_address; /* Base address of ram. */ | |
107 | unsigned size; /* Size of ram. */ | |
108 | unsigned8 *data; /* Pointer to ram memory. */ | |
109 | const char *file_name; /* Path of ram file. */ | |
110 | int fd; /* File description of opened ram file. */ | |
111 | enum nvram_mode mode; /* How load/save ram file. */ | |
112 | }; | |
113 | ||
114 | ||
115 | ||
116 | /* Finish off the partially created hw device. Attach our local | |
117 | callbacks. Wire up our port names etc. */ | |
118 | ||
119 | static hw_io_read_buffer_method nvram_io_read_buffer; | |
120 | static hw_io_write_buffer_method nvram_io_write_buffer; | |
121 | ||
122 | ||
123 | ||
124 | static void | |
125 | attach_nvram_regs (struct hw *me, struct nvram *controller) | |
126 | { | |
127 | unsigned_word attach_address; | |
128 | int attach_space; | |
129 | unsigned attach_size; | |
130 | reg_property_spec reg; | |
131 | int result, oerrno; | |
132 | ||
e0709f50 AC |
133 | /* Get ram bank description (base and size). */ |
134 | if (hw_find_property (me, "reg") == NULL) | |
135 | hw_abort (me, "Missing \"reg\" property"); | |
136 | ||
137 | if (!hw_find_reg_array_property (me, "reg", 0, ®)) | |
138 | hw_abort (me, "\"reg\" property must contain one addr/size entry"); | |
139 | ||
140 | hw_unit_address_to_attach_address (hw_parent (me), | |
141 | ®.address, | |
142 | &attach_space, | |
143 | &attach_address, | |
144 | me); | |
145 | hw_unit_size_to_attach_size (hw_parent (me), | |
146 | ®.size, | |
147 | &attach_size, me); | |
148 | ||
149 | hw_attach_address (hw_parent (me), 0, | |
150 | attach_space, attach_address, attach_size, | |
151 | me); | |
152 | ||
153 | controller->mode = NVRAM_SAVE_ALL; | |
154 | controller->base_address = attach_address; | |
155 | controller->size = attach_size; | |
156 | controller->fd = -1; | |
157 | ||
158 | /* Get the file where the ram content must be loaded/saved. */ | |
159 | if(hw_find_property (me, "file") == NULL) | |
160 | hw_abort (me, "Missing \"file\" property"); | |
161 | ||
162 | controller->file_name = hw_find_string_property (me, "file"); | |
163 | ||
164 | /* Get the mode which defines how to save the memory. */ | |
165 | if(hw_find_property (me, "mode") != NULL) | |
166 | { | |
167 | const char *value = hw_find_string_property (me, "mode"); | |
168 | ||
169 | if (strcmp (value, "map") == 0) | |
170 | controller->mode = NVRAM_MAP_FILE; | |
171 | else if (strcmp (value, "save-modified") == 0) | |
172 | controller->mode = NVRAM_SAVE_MODIFIED; | |
173 | else if (strcmp (value, "save-all") == 0) | |
174 | controller->mode = NVRAM_SAVE_ALL; | |
175 | else | |
176 | hw_abort (me, "illegal value for mode parameter `%s': " | |
177 | "use map, save-modified or save-all", value); | |
178 | } | |
179 | ||
180 | /* Initialize the ram by loading/mapping the file in memory. | |
181 | If the file does not exist, create and give it some content. */ | |
182 | switch (controller->mode) | |
183 | { | |
184 | case NVRAM_MAP_FILE: | |
185 | hw_abort (me, "'map' mode is not yet implemented, use 'save-modified'"); | |
186 | break; | |
187 | ||
188 | case NVRAM_SAVE_MODIFIED: | |
189 | case NVRAM_SAVE_ALL: | |
6e73e7ed | 190 | controller->data = (char*) hw_malloc (me, attach_size); |
e0709f50 AC |
191 | if (controller->data == 0) |
192 | hw_abort (me, "Not enough memory, try to use the mode 'map'"); | |
193 | ||
194 | memset (controller->data, 0, attach_size); | |
195 | controller->fd = open (controller->file_name, O_RDWR); | |
196 | if (controller->fd < 0) | |
197 | { | |
198 | controller->fd = open (controller->file_name, | |
199 | O_RDWR | O_CREAT, 0644); | |
200 | if (controller->fd < 0) | |
201 | hw_abort (me, "Cannot open or create file '%s'", | |
202 | controller->file_name); | |
203 | result = write (controller->fd, controller->data, attach_size); | |
204 | if (result != attach_size) | |
205 | { | |
206 | oerrno = errno; | |
6e73e7ed | 207 | hw_free (me, controller->data); |
e0709f50 AC |
208 | close (controller->fd); |
209 | errno = oerrno; | |
210 | hw_abort (me, "Failed to save the ram content"); | |
211 | } | |
212 | } | |
213 | else | |
214 | { | |
215 | result = read (controller->fd, controller->data, attach_size); | |
216 | if (result != attach_size) | |
217 | { | |
218 | oerrno = errno; | |
6e73e7ed | 219 | hw_free (me, controller->data); |
e0709f50 AC |
220 | close (controller->fd); |
221 | errno = oerrno; | |
222 | hw_abort (me, "Failed to load the ram content"); | |
223 | } | |
224 | } | |
225 | if (controller->mode == NVRAM_SAVE_ALL) | |
226 | { | |
227 | close (controller->fd); | |
228 | controller->fd = -1; | |
229 | } | |
230 | break; | |
231 | ||
232 | default: | |
233 | break; | |
234 | } | |
235 | } | |
236 | ||
237 | ||
238 | static void | |
239 | nvram_finish (struct hw *me) | |
240 | { | |
241 | struct nvram *controller; | |
242 | ||
243 | controller = HW_ZALLOC (me, struct nvram); | |
244 | ||
245 | set_hw_data (me, controller); | |
246 | set_hw_io_read_buffer (me, nvram_io_read_buffer); | |
247 | set_hw_io_write_buffer (me, nvram_io_write_buffer); | |
248 | ||
249 | /* Attach ourself to our parent bus. */ | |
250 | attach_nvram_regs (me, controller); | |
251 | } | |
252 | ||
253 | ||
254 | ||
255 | /* generic read/write */ | |
256 | ||
257 | static unsigned | |
258 | nvram_io_read_buffer (struct hw *me, | |
259 | void *dest, | |
260 | int space, | |
261 | unsigned_word base, | |
262 | unsigned nr_bytes) | |
263 | { | |
264 | struct nvram *controller = hw_data (me); | |
265 | ||
266 | HW_TRACE ((me, "read 0x%08lx %d [%ld]", | |
267 | (long) base, (int) nr_bytes, | |
268 | (long) (base - controller->base_address))); | |
269 | ||
270 | base -= controller->base_address; | |
271 | if (base + nr_bytes > controller->size) | |
272 | nr_bytes = controller->size - base; | |
273 | ||
274 | memcpy (dest, &controller->data[base], nr_bytes); | |
275 | return nr_bytes; | |
276 | } | |
277 | ||
278 | ||
279 | ||
280 | static unsigned | |
281 | nvram_io_write_buffer (struct hw *me, | |
282 | const void *source, | |
283 | int space, | |
284 | unsigned_word base, | |
285 | unsigned nr_bytes) | |
286 | { | |
287 | struct nvram *controller = hw_data (me); | |
288 | ||
289 | HW_TRACE ((me, "write 0x%08lx %d [%ld]", | |
290 | (long) base, (int) nr_bytes, | |
291 | (long) (base - controller->base_address))); | |
292 | ||
293 | base -= controller->base_address; | |
294 | if (base + nr_bytes > controller->size) | |
295 | nr_bytes = controller->size - base; | |
296 | ||
297 | switch (controller->mode) | |
298 | { | |
299 | case NVRAM_SAVE_ALL: | |
300 | { | |
301 | int fd, result, oerrno; | |
302 | ||
303 | fd = open (controller->file_name, O_WRONLY, 0644); | |
304 | if (fd < 0) | |
305 | { | |
306 | return 0; | |
307 | } | |
308 | ||
309 | memcpy (&controller->data[base], source, nr_bytes); | |
310 | result = write (fd, controller->data, controller->size); | |
311 | oerrno = errno; | |
312 | close (fd); | |
313 | errno = oerrno; | |
314 | ||
315 | if (result != controller->size) | |
316 | { | |
317 | return 0; | |
318 | } | |
319 | return nr_bytes; | |
320 | } | |
321 | ||
322 | case NVRAM_SAVE_MODIFIED: | |
323 | { | |
324 | off_t pos; | |
325 | int result; | |
326 | ||
327 | pos = lseek (controller->fd, (off_t) base, SEEK_SET); | |
328 | if (pos != (off_t) base) | |
329 | return 0; | |
330 | ||
331 | result = write (controller->fd, source, nr_bytes); | |
332 | if (result < 0) | |
333 | return 0; | |
334 | ||
335 | nr_bytes = result; | |
336 | break; | |
337 | } | |
338 | ||
339 | default: | |
340 | break; | |
341 | } | |
342 | memcpy (&controller->data[base], source, nr_bytes); | |
343 | return nr_bytes; | |
344 | } | |
345 | ||
346 | ||
347 | const struct hw_descriptor dv_nvram_descriptor[] = { | |
348 | { "nvram", nvram_finish, }, | |
349 | { NULL }, | |
350 | }; | |
351 |