1 // SPDX-License-Identifier: GPL-2.0-only
3 * Driver for MikroTik RouterBoot soft config.
5 * Copyright (C) 2020 Thibaut VARĂˆNE <hacks+kernel@slashdirt.org>
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published
9 * by the Free Software Foundation.
11 * This driver exposes the data encoded in the "soft_config" flash segment of
12 * MikroTik RouterBOARDs devices. It presents the data in a sysfs folder
13 * named "soft_config". The data is presented in a user/machine-friendly way
14 * with just as much parsing as can be generalized across mikrotik platforms
15 * (as inferred from reverse-engineering).
17 * The known soft_config tags are presented in the "soft_config" sysfs folder,
18 * with the addition of one specific file named "commit", which is only
19 * available if the driver supports writes to the mtd device: no modifications
20 * made to any of the other attributes are actually written back to flash media
21 * until a true value is input into this file (e.g. [Yy1]). This is to avoid
22 * unnecessary flash wear, and to permit to revert all changes by issuing a
23 * false value ([Nn0]). Reading the content of this file shows the current
24 * status of the driver: if the data in sysfs matches the content of the
25 * soft_config partition, the file will read "clean". Otherwise, it will read
28 * The writeable sysfs files presented by this driver will accept only inputs
29 * which are in a valid range for the given tag. As a design choice, the driver
30 * will not assess whether the inputs are identical to the existing data.
32 * Note: PAGE_SIZE is assumed to be >= 4K, hence the device attribute show
33 * routines need not check for output overflow.
35 * Some constant defines extracted from rbcfg.h by Gabor Juhos
36 * <juhosg@openwrt.org>
39 #include <linux/types.h>
40 #include <linux/init.h>
41 #include <linux/kernel.h>
42 #include <linux/slab.h>
43 #include <linux/errno.h>
44 #include <linux/kobject.h>
45 #include <linux/string.h>
46 #include <linux/mtd/mtd.h>
47 #include <linux/sysfs.h>
48 #include <linux/version.h>
49 #include <linux/capability.h>
50 #include <linux/spinlock.h>
51 #include <linux/crc32.h>
54 #include <asm/mach-ath79/ath79.h>
57 #include "routerboot.h"
59 #define RB_SOFTCONFIG_VER "0.02"
60 #define RB_SC_PR_PFX "[rb_softconfig] "
63 * mtd operations before 4.17 are asynchronous, not handled by this code
64 * Also make the driver act read-only if 4K_SECTORS are not enabled, since they
65 * are require to handle partial erasing of the small soft_config partition.
67 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 17, 0)) && defined(CONFIG_MTD_SPI_NOR_USE_4K_SECTORS)
68 #define RB_SC_HAS_WRITE_SUPPORT true
69 #define RB_SC_WMODE S_IWUSR
70 #define RB_SC_RMODE S_IRUSR
72 #define RB_SC_HAS_WRITE_SUPPORT false
74 #define RB_SC_RMODE S_IRUSR
77 /* ID values for software settings */
78 #define RB_SCID_UART_SPEED 0x01 // u32*1
79 #define RB_SCID_BOOT_DELAY 0x02 // u32*1
80 #define RB_SCID_BOOT_DEVICE 0x03 // u32*1
81 #define RB_SCID_BOOT_KEY 0x04 // u32*1
82 #define RB_SCID_CPU_MODE 0x05 // u32*1
83 #define RB_SCID_BIOS_VERSION 0x06 // str
84 #define RB_SCID_BOOT_PROTOCOL 0x09 // u32*1
85 #define RB_SCID_CPU_FREQ_IDX 0x0C // u32*1
86 #define RB_SCID_BOOTER 0x0D // u32*1
87 #define RB_SCID_SILENT_BOOT 0x0F // u32*1
89 * protected_routerboot seems to use tag 0x1F. It only works in combination with
90 * RouterOS, resulting in a wiped board otherwise, so it's not implemented here.
91 * The tag values are as follows:
93 * - on: the lower halfword encodes the max value in s for the reset feature,
94 * the higher halfword encodes the min value in s for the reset feature.
95 * Default value when on: 0x00140258: 0x14 = 20s / 0x258= 600s
96 * See details here: https://wiki.mikrotik.com/wiki/Manual:RouterBOARD_settings#Protected_bootloader
101 #define RB_UART_SPEED_115200 0
102 #define RB_UART_SPEED_57600 1
103 #define RB_UART_SPEED_38400 2
104 #define RB_UART_SPEED_19200 3
105 #define RB_UART_SPEED_9600 4
106 #define RB_UART_SPEED_4800 5
107 #define RB_UART_SPEED_2400 6
108 #define RB_UART_SPEED_1200 7
109 #define RB_UART_SPEED_OFF 8
111 /* valid boot delay: 1 - 9s in 1s increment */
112 #define RB_BOOT_DELAY_MIN 1
113 #define RB_BOOT_DELAY_MAX 9
115 #define RB_BOOT_DEVICE_ETHER 0 // "boot over Ethernet"
116 #define RB_BOOT_DEVICE_NANDETH 1 // "boot from NAND, if fail then Ethernet"
117 #define RB_BOOT_DEVICE_CFCARD 2 // (not available in rbcfg)
118 #define RB_BOOT_DEVICE_ETHONCE 3 // "boot Ethernet once, then NAND"
119 #define RB_BOOT_DEVICE_NANDONLY 5 // "boot from NAND only"
120 #define RB_BOOT_DEVICE_FLASHCFG 7 // "boot in flash configuration mode"
121 #define RB_BOOT_DEVICE_FLSHONCE 8 // "boot in flash configuration mode once, then NAND"
124 * ATH79 CPU frequency indices.
125 * It is unknown if they apply to all ATH79 RBs, and some do not seem to feature
126 * the up levels (QCA955x), while U3 is presumably AR9344-only.
128 #define RB_CPU_FREQ_IDX_ATH79_D2 (0 << 3)
129 #define RB_CPU_FREQ_IDX_ATH79_D1 (1 << 3) // 0x8
130 #define RB_CPU_FREQ_IDX_ATH79_N0 (2 << 3) // 0x10 - factory freq for many devices
131 #define RB_CPU_FREQ_IDX_ATH79_U1 (3 << 3) // 0x18
132 #define RB_CPU_FREQ_IDX_ATH79_U2 (4 << 3) // 0x20
133 #define RB_CPU_FREQ_IDX_ATH79_U3 (5 << 3) // 0x28
135 #define RB_CPU_FREQ_IDX_ATH79_MIN 0 // all devices support lowest setting
136 #define RB_CPU_FREQ_IDX_ATH79_AR9334_MAX 5 // stops at U3
137 #define RB_CPU_FREQ_IDX_ATH79_QCA953X_MAX 4 // stops at U2
138 #define RB_CPU_FREQ_IDX_ATH79_QCA9556_MAX 2 // stops at N0
139 #define RB_CPU_FREQ_IDX_ATH79_QCA9558_MAX 3 // stops at U1
141 #define RB_SC_CRC32_OFFSET 4 // located right after magic
143 static struct kobject
*sc_kobj
;
145 static size_t sc_buflen
;
146 static rwlock_t sc_bufrwl
; // rw lock to sc_buf
148 /* MUST be used with lock held */
149 #define RB_SC_CLRCRC() *(u32 *)(sc_buf + RB_SC_CRC32_OFFSET) = 0
150 #define RB_SC_GETCRC() *(u32 *)(sc_buf + RB_SC_CRC32_OFFSET)
151 #define RB_SC_SETCRC(_crc) *(u32 *)(sc_buf + RB_SC_CRC32_OFFSET) = (_crc)
158 #define RB_SC_TVS(_val, _str) { \
163 static ssize_t
sc_tag_show_u32tvs(const u8
*pld
, u16 pld_len
, char *buf
,
164 const struct sc_u32tvs tvs
[], const int tvselmts
)
168 u32 data
; // cpu-endian
174 if (sizeof(data
) != pld_len
)
177 read_lock(&sc_bufrwl
);
178 data
= *(u32
*)pld
; // pld aliases sc_buf
179 read_unlock(&sc_bufrwl
);
181 for (i
= 0; i
< tvselmts
; i
++) {
182 fmt
= (tvs
[i
].val
== data
) ? "[%s] " : "%s ";
183 out
+= sprintf(out
, fmt
, tvs
[i
].str
);
186 out
+= sprintf(out
, "\n");
190 static ssize_t
sc_tag_store_u32tvs(const u8
*pld
, u16 pld_len
, const char *buf
, size_t count
,
191 const struct sc_u32tvs tvs
[], const int tvselmts
)
198 if (sizeof(u32
) != pld_len
)
201 for (i
= 0; i
< tvselmts
; i
++) {
202 if (sysfs_streq(buf
, tvs
[i
].str
)) {
203 write_lock(&sc_bufrwl
);
204 *(u32
*)pld
= tvs
[i
].val
; // pld aliases sc_buf
206 write_unlock(&sc_bufrwl
);
215 const char *strfalse
;
219 static ssize_t
sc_tag_show_boolts(const u8
*pld
, u16 pld_len
, char *buf
,
220 const struct sc_boolts
*bts
)
224 u32 data
; // cpu-endian
226 if (sizeof(data
) != pld_len
)
229 read_lock(&sc_bufrwl
);
230 data
= *(u32
*)pld
; // pld aliases sc_buf
231 read_unlock(&sc_bufrwl
);
233 fmt
= (data
) ? "%s [%s]\n" : "[%s] %s\n";
234 out
+= sprintf(out
, fmt
, bts
->strfalse
, bts
->strtrue
);
239 static ssize_t
sc_tag_store_boolts(const u8
*pld
, u16 pld_len
, const char *buf
, size_t count
,
240 const struct sc_boolts
*bts
)
242 u32 data
; // cpu-endian
244 if (sizeof(data
) != pld_len
)
247 if (sysfs_streq(buf
, bts
->strfalse
))
249 else if (sysfs_streq(buf
, bts
->strtrue
))
254 write_lock(&sc_bufrwl
);
255 *(u32
*)pld
= data
; // pld aliases sc_buf
257 write_unlock(&sc_bufrwl
);
261 static struct sc_u32tvs
const sc_uartspeeds
[] = {
262 RB_SC_TVS(RB_UART_SPEED_OFF
, "off"),
263 RB_SC_TVS(RB_UART_SPEED_1200
, "1200"),
264 RB_SC_TVS(RB_UART_SPEED_2400
, "2400"),
265 RB_SC_TVS(RB_UART_SPEED_4800
, "4800"),
266 RB_SC_TVS(RB_UART_SPEED_9600
, "9600"),
267 RB_SC_TVS(RB_UART_SPEED_19200
, "19200"),
268 RB_SC_TVS(RB_UART_SPEED_38400
, "38400"),
269 RB_SC_TVS(RB_UART_SPEED_57600
, "57600"),
270 RB_SC_TVS(RB_UART_SPEED_115200
, "115200"),
274 * While the defines are carried over from rbcfg, use strings that more clearly
275 * show the actual setting purpose (especially since the NAND* settings apply
276 * to both nand- and nor-based devices). "cfcard" was disabled in rbcfg: disable
279 static struct sc_u32tvs
const sc_bootdevices
[] = {
280 RB_SC_TVS(RB_BOOT_DEVICE_ETHER
, "eth"),
281 RB_SC_TVS(RB_BOOT_DEVICE_NANDETH
, "flasheth"),
282 //RB_SC_TVS(RB_BOOT_DEVICE_CFCARD, "cfcard"),
283 RB_SC_TVS(RB_BOOT_DEVICE_ETHONCE
, "ethonce"),
284 RB_SC_TVS(RB_BOOT_DEVICE_NANDONLY
, "flash"),
285 RB_SC_TVS(RB_BOOT_DEVICE_FLASHCFG
, "cfg"),
286 RB_SC_TVS(RB_BOOT_DEVICE_FLSHONCE
, "cfgonce"),
289 static struct sc_boolts
const sc_bootkey
= {
294 static struct sc_boolts
const sc_cpumode
= {
295 .strfalse
= "powersave",
296 .strtrue
= "regular",
299 static struct sc_boolts
const sc_bootproto
= {
304 static struct sc_boolts
const sc_booter
= {
305 .strfalse
= "regular",
309 static struct sc_boolts
const sc_silent_boot
= {
314 #define SC_TAG_SHOW_STORE_U32TVS_FUNCS(_name) \
315 static ssize_t sc_tag_show_##_name(const u8 *pld, u16 pld_len, char *buf) \
317 return sc_tag_show_u32tvs(pld, pld_len, buf, sc_##_name, ARRAY_SIZE(sc_##_name)); \
319 static ssize_t sc_tag_store_##_name(const u8 *pld, u16 pld_len, const char *buf, size_t count) \
321 return sc_tag_store_u32tvs(pld, pld_len, buf, count, sc_##_name, ARRAY_SIZE(sc_##_name)); \
324 #define SC_TAG_SHOW_STORE_BOOLTS_FUNCS(_name) \
325 static ssize_t sc_tag_show_##_name(const u8 *pld, u16 pld_len, char *buf) \
327 return sc_tag_show_boolts(pld, pld_len, buf, &sc_##_name); \
329 static ssize_t sc_tag_store_##_name(const u8 *pld, u16 pld_len, const char *buf, size_t count) \
331 return sc_tag_store_boolts(pld, pld_len, buf, count, &sc_##_name); \
334 SC_TAG_SHOW_STORE_U32TVS_FUNCS(uartspeeds
)
335 SC_TAG_SHOW_STORE_U32TVS_FUNCS(bootdevices
)
336 SC_TAG_SHOW_STORE_BOOLTS_FUNCS(bootkey
)
337 SC_TAG_SHOW_STORE_BOOLTS_FUNCS(cpumode
)
338 SC_TAG_SHOW_STORE_BOOLTS_FUNCS(bootproto
)
339 SC_TAG_SHOW_STORE_BOOLTS_FUNCS(booter
)
340 SC_TAG_SHOW_STORE_BOOLTS_FUNCS(silent_boot
)
342 static ssize_t
sc_tag_show_bootdelays(const u8
*pld
, u16 pld_len
, char *buf
)
346 u32 data
; // cpu-endian
349 if (sizeof(data
) != pld_len
)
352 read_lock(&sc_bufrwl
);
353 data
= *(u32
*)pld
; // pld aliases sc_buf
354 read_unlock(&sc_bufrwl
);
356 for (i
= RB_BOOT_DELAY_MIN
; i
<= RB_BOOT_DELAY_MAX
; i
++) {
357 fmt
= (i
== data
) ? "[%d] " : "%d ";
358 out
+= sprintf(out
, fmt
, i
);
361 out
+= sprintf(out
, "\n");
365 static ssize_t
sc_tag_store_bootdelays(const u8
*pld
, u16 pld_len
, const char *buf
, size_t count
)
367 u32 data
; // cpu-endian
370 if (sizeof(data
) != pld_len
)
373 ret
= kstrtou32(buf
, 10, &data
);
377 if ((data
< RB_BOOT_DELAY_MIN
) || (RB_BOOT_DELAY_MAX
< data
))
380 write_lock(&sc_bufrwl
);
381 *(u32
*)pld
= data
; // pld aliases sc_buf
383 write_unlock(&sc_bufrwl
);
388 /* Support CPU frequency accessors only when the tag format has been asserted */
389 #if defined(CONFIG_ATH79)
390 static struct sc_u32tvs
const sc_cpufreq_indexes_ath79
[] = {
391 RB_SC_TVS(RB_CPU_FREQ_IDX_ATH79_D2
, "-2"),
392 RB_SC_TVS(RB_CPU_FREQ_IDX_ATH79_D1
, "-1"),
393 RB_SC_TVS(RB_CPU_FREQ_IDX_ATH79_N0
, "0"),
394 RB_SC_TVS(RB_CPU_FREQ_IDX_ATH79_U1
, "+1"),
395 RB_SC_TVS(RB_CPU_FREQ_IDX_ATH79_U2
, "+2"),
396 RB_SC_TVS(RB_CPU_FREQ_IDX_ATH79_U3
, "+3"),
399 static int sc_tag_cpufreq_ath79_idxmax(void)
401 int idx_max
= -EOPNOTSUPP
;
404 idx_max
= RB_CPU_FREQ_IDX_ATH79_AR9334_MAX
;
405 else if (soc_is_qca953x())
406 idx_max
= RB_CPU_FREQ_IDX_ATH79_QCA953X_MAX
;
407 else if (soc_is_qca9556())
408 idx_max
= RB_CPU_FREQ_IDX_ATH79_QCA9556_MAX
;
409 else if (soc_is_qca9558())
410 idx_max
= RB_CPU_FREQ_IDX_ATH79_QCA9558_MAX
;
415 static ssize_t
sc_tag_show_cpufreq_indexes(const u8
*pld
, u16 pld_len
, char * buf
)
417 return sc_tag_show_u32tvs(pld
, pld_len
, buf
, sc_cpufreq_indexes_ath79
, sc_tag_cpufreq_ath79_idxmax()+1);
420 static ssize_t
sc_tag_store_cpufreq_indexes(const u8
*pld
, u16 pld_len
, const char *buf
, size_t count
)
422 return sc_tag_store_u32tvs(pld
, pld_len
, buf
, count
, sc_cpufreq_indexes_ath79
, sc_tag_cpufreq_ath79_idxmax()+1);
425 /* By default we only show the raw value to help with reverse-engineering */
426 #define sc_tag_show_cpufreq_indexes routerboot_tag_show_u32s
427 #define sc_tag_store_cpufreq_indexes NULL
430 static ssize_t
sc_attr_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
432 static ssize_t
sc_attr_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
433 const char *buf
, size_t count
);
435 /* Array of known tags to publish in sysfs */
436 static struct sc_attr
{
438 /* sysfs tag show attribute. Must lock sc_buf when dereferencing pld */
439 ssize_t (* const tshow
)(const u8
*pld
, u16 pld_len
, char *buf
);
440 /* sysfs tag store attribute. Must lock sc_buf when dereferencing pld */
441 ssize_t (* const tstore
)(const u8
*pld
, u16 pld_len
, const char *buf
, size_t count
);
442 struct kobj_attribute kattr
;
447 .tag_id
= RB_SCID_UART_SPEED
,
448 .tshow
= sc_tag_show_uartspeeds
,
449 .tstore
= sc_tag_store_uartspeeds
,
450 .kattr
= __ATTR(uart_speed
, RB_SC_RMODE
|RB_SC_WMODE
, sc_attr_show
, sc_attr_store
),
452 .tag_id
= RB_SCID_BOOT_DELAY
,
453 .tshow
= sc_tag_show_bootdelays
,
454 .tstore
= sc_tag_store_bootdelays
,
455 .kattr
= __ATTR(boot_delay
, RB_SC_RMODE
|RB_SC_WMODE
, sc_attr_show
, sc_attr_store
),
457 .tag_id
= RB_SCID_BOOT_DEVICE
,
458 .tshow
= sc_tag_show_bootdevices
,
459 .tstore
= sc_tag_store_bootdevices
,
460 .kattr
= __ATTR(boot_device
, RB_SC_RMODE
|RB_SC_WMODE
, sc_attr_show
, sc_attr_store
),
462 .tag_id
= RB_SCID_BOOT_KEY
,
463 .tshow
= sc_tag_show_bootkey
,
464 .tstore
= sc_tag_store_bootkey
,
465 .kattr
= __ATTR(boot_key
, RB_SC_RMODE
|RB_SC_WMODE
, sc_attr_show
, sc_attr_store
),
467 .tag_id
= RB_SCID_CPU_MODE
,
468 .tshow
= sc_tag_show_cpumode
,
469 .tstore
= sc_tag_store_cpumode
,
470 .kattr
= __ATTR(cpu_mode
, RB_SC_RMODE
|RB_SC_WMODE
, sc_attr_show
, sc_attr_store
),
472 .tag_id
= RB_SCID_BIOS_VERSION
,
473 .tshow
= routerboot_tag_show_string
,
475 .kattr
= __ATTR(bios_version
, RB_SC_RMODE
, sc_attr_show
, NULL
),
477 .tag_id
= RB_SCID_BOOT_PROTOCOL
,
478 .tshow
= sc_tag_show_bootproto
,
479 .tstore
= sc_tag_store_bootproto
,
480 .kattr
= __ATTR(boot_proto
, RB_SC_RMODE
|RB_SC_WMODE
, sc_attr_show
, sc_attr_store
),
482 .tag_id
= RB_SCID_CPU_FREQ_IDX
,
483 .tshow
= sc_tag_show_cpufreq_indexes
,
484 .tstore
= sc_tag_store_cpufreq_indexes
,
485 .kattr
= __ATTR(cpufreq_index
, RB_SC_RMODE
|RB_SC_WMODE
, sc_attr_show
, sc_attr_store
),
487 .tag_id
= RB_SCID_BOOTER
,
488 .tshow
= sc_tag_show_booter
,
489 .tstore
= sc_tag_store_booter
,
490 .kattr
= __ATTR(booter
, RB_SC_RMODE
|RB_SC_WMODE
, sc_attr_show
, sc_attr_store
),
492 .tag_id
= RB_SCID_SILENT_BOOT
,
493 .tshow
= sc_tag_show_silent_boot
,
494 .tstore
= sc_tag_store_silent_boot
,
495 .kattr
= __ATTR(silent_boot
, RB_SC_RMODE
|RB_SC_WMODE
, sc_attr_show
, sc_attr_store
),
499 static ssize_t
sc_attr_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
502 const struct sc_attr
*sc_attr
;
506 sc_attr
= container_of(attr
, typeof(*sc_attr
), kattr
);
508 if (!sc_attr
->pld_len
)
511 pld
= sc_buf
+ sc_attr
->pld_ofs
; // pld aliases sc_buf -> lock!
512 pld_len
= sc_attr
->pld_len
;
514 return sc_attr
->tshow(pld
, pld_len
, buf
);
517 static ssize_t
sc_attr_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
518 const char *buf
, size_t count
)
520 const struct sc_attr
*sc_attr
;
524 if (!RB_SC_HAS_WRITE_SUPPORT
)
527 if (!capable(CAP_SYS_ADMIN
))
530 sc_attr
= container_of(attr
, typeof(*sc_attr
), kattr
);
532 if (!sc_attr
->tstore
)
535 if (!sc_attr
->pld_len
)
538 pld
= sc_buf
+ sc_attr
->pld_ofs
; // pld aliases sc_buf -> lock!
539 pld_len
= sc_attr
->pld_len
;
541 return sc_attr
->tstore(pld
, pld_len
, buf
, count
);
545 * Shows the current buffer status:
546 * "clean": the buffer is in sync with the mtd data
547 * "dirty": the buffer is out of sync with the mtd data
549 static ssize_t
sc_commit_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
556 read_lock(&sc_bufrwl
);
557 crc
= RB_SC_GETCRC();
558 read_unlock(&sc_bufrwl
);
560 str
= (crc
) ? "clean" : "dirty";
561 out
+= sprintf(out
, "%s\n", str
);
567 * Performs buffer flushing:
568 * This routine expects an input compatible with kstrtobool().
569 * - a "false" input discards the current changes and reads data back from mtd.
570 * - a "true" input commits the current changes to mtd.
571 * If there is no pending changes, this routine is a no-op.
572 * Handling failures is left as an exercise to userspace.
574 static ssize_t
sc_commit_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
575 const char *buf
, size_t count
)
577 struct mtd_info
*mtd
;
578 struct erase_info ei
;
579 size_t bytes_rw
, ret
= count
;
583 if (!RB_SC_HAS_WRITE_SUPPORT
)
586 read_lock(&sc_bufrwl
);
587 crc
= RB_SC_GETCRC();
588 read_unlock(&sc_bufrwl
);
591 return count
; // NO-OP
593 ret
= kstrtobool(buf
, &flush
);
597 mtd
= get_mtd_device_nm(RB_MTD_SOFT_CONFIG
); // TODO allow override
601 write_lock(&sc_bufrwl
);
602 if (!flush
) // reread
603 ret
= mtd_read(mtd
, 0, mtd
->size
, &bytes_rw
, sc_buf
);
604 else { // crc32 + commit
606 * CRC32 is computed on the entire buffer, excluding the CRC
607 * value itself. CRC is already null when we reach this point,
608 * so we can compute the CRC32 on the buffer as is.
609 * The expected CRC32 is Ethernet FCS style, meaning the seed is
610 * ~0 and the final result is also bitflipped.
613 crc
= ~crc32(~0, sc_buf
, sc_buflen
);
617 * The soft_config partition is assumed to be entirely contained
618 * in a single eraseblock.
623 ret
= mtd_erase(mtd
, &ei
);
625 ret
= mtd_write(mtd
, 0, mtd
->size
, &bytes_rw
, sc_buf
);
628 * Handling mtd_write() failure here is a tricky situation. The
629 * proposed approach is to let userspace deal with retrying,
630 * with the caveat that it must try to flush the buffer again as
631 * rereading the mtd contents could potentially read garbage.
632 * The rationale is: even if we keep a shadow buffer of the
633 * original content, there is no guarantee that we will ever be
634 * able to write it anyway.
635 * Regardless, it appears that RouterBOOT will ignore an invalid
636 * soft_config (including a completely wiped segment) and will
637 * write back factory defaults when it happens.
640 write_unlock(&sc_bufrwl
);
645 if (bytes_rw
!= sc_buflen
) {
653 RB_SC_CLRCRC(); // mark buffer content as dirty/invalid
657 static struct kobj_attribute sc_kattrcommit
= __ATTR(commit
, RB_SC_RMODE
|RB_SC_WMODE
, sc_commit_show
, sc_commit_store
);
659 int __init
rb_softconfig_init(struct kobject
*rb_kobj
)
661 struct mtd_info
*mtd
;
662 size_t bytes_read
, buflen
;
670 // TODO allow override
671 mtd
= get_mtd_device_nm(RB_MTD_SOFT_CONFIG
);
675 sc_buflen
= mtd
->size
;
676 sc_buf
= kmalloc(sc_buflen
, GFP_KERNEL
);
680 ret
= mtd_read(mtd
, 0, sc_buflen
, &bytes_read
, sc_buf
);
685 if (bytes_read
!= sc_buflen
) {
690 /* Check we have what we expect */
691 magic
= *(const u32
*)sc_buf
;
692 if (RB_MAGIC_SOFT
!= magic
) {
697 /* Skip magic and 32bit CRC located immediately after */
698 buf
= sc_buf
+ (sizeof(magic
) + sizeof(u32
));
699 buflen
= sc_buflen
- (sizeof(magic
) + sizeof(u32
));
703 sc_kobj
= kobject_create_and_add(RB_MTD_SOFT_CONFIG
, rb_kobj
);
707 rwlock_init(&sc_bufrwl
);
709 /* Locate and publish all known tags */
710 for (i
= 0; i
< ARRAY_SIZE(sc_attrs
); i
++) {
711 ret
= routerboot_tag_find(buf
, buflen
, sc_attrs
[i
].tag_id
,
712 &sc_attrs
[i
].pld_ofs
, &sc_attrs
[i
].pld_len
);
714 sc_attrs
[i
].pld_ofs
= sc_attrs
[i
].pld_len
= 0;
718 /* Account for skipped magic and crc32 */
719 sc_attrs
[i
].pld_ofs
+= sizeof(magic
) + sizeof(u32
);
721 ret
= sysfs_create_file(sc_kobj
, &sc_attrs
[i
].kattr
.attr
);
723 pr_warn(RB_SC_PR_PFX
"Could not create %s sysfs entry (%d)\n",
724 sc_attrs
[i
].kattr
.attr
.name
, ret
);
727 /* Finally add the 'commit' attribute */
728 if (RB_SC_HAS_WRITE_SUPPORT
) {
729 ret
= sysfs_create_file(sc_kobj
, &sc_kattrcommit
.attr
);
731 pr_err(RB_SC_PR_PFX
"Could not create %s sysfs entry (%d), aborting!\n",
732 sc_kattrcommit
.attr
.name
, ret
);
733 goto sysfsfail
; // required attribute
737 pr_info("MikroTik RouterBOARD software configuration sysfs driver v" RB_SOFTCONFIG_VER
"\n");
742 kobject_put(sc_kobj
);
750 void __exit
rb_softconfig_exit(void)
752 kobject_put(sc_kobj
);