--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for MikroTik RouterBoot soft config.
+ *
+ * Copyright (C) 2020 Thibaut VARÈNE <hacks+kernel@slashdirt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * This driver exposes the data encoded in the "soft_config" flash segment of
+ * MikroTik RouterBOARDs devices. It presents the data in a sysfs folder
+ * named "soft_config". The data is presented in a user/machine-friendly way
+ * with just as much parsing as can be generalized across mikrotik platforms
+ * (as inferred from reverse-engineering).
+ *
+ * The known soft_config tags are presented in the "soft_config" sysfs folder,
+ * with the addition of one specific file named "commit", which is only
+ * available if the driver supports writes to the mtd device: no modifications
+ * made to any of the other attributes are actually written back to flash media
+ * until a true value is input into this file (e.g. [Yy1]). This is to avoid
+ * unnecessary flash wear, and to permit to revert all changes by issuing a
+ * false value ([Nn0]). Reading the content of this file shows the current
+ * status of the driver: if the data in sysfs matches the content of the
+ * soft_config partition, the file will read "clean". Otherwise, it will read
+ * "dirty".
+ *
+ * The writeable sysfs files presented by this driver will accept only inputs
+ * which are in a valid range for the given tag. As a design choice, the driver
+ * will not assess whether the inputs are identical to the existing data.
+ *
+ * Note: PAGE_SIZE is assumed to be >= 4K, hence the device attribute show
+ * routines need not check for output overflow.
+ *
+ * Some constant defines extracted from rbcfg.h by Gabor Juhos
+ * <juhosg@openwrt.org>
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/kobject.h>
+#include <linux/string.h>
+#include <linux/mtd/mtd.h>
+#include <linux/sysfs.h>
+#include <linux/version.h>
+#include <linux/capability.h>
+#include <linux/spinlock.h>
+#include <linux/crc32.h>
+
+#include "routerboot.h"
+
+#define RB_SOFTCONFIG_VER "0.01"
+#define RB_SC_PR_PFX "[rb_softconfig] "
+
+/*
+ * mtd operations before 4.17 are asynchronous, not handled by this code
+ * Also make the driver act read-only if 4K_SECTORS are not enabled, since they
+ * are require to handle partial erasing of the small soft_config partition.
+ */
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 17, 0)) && defined(CONFIG_MTD_SPI_NOR_USE_4K_SECTORS)
+ #define RB_SC_HAS_WRITE_SUPPORT true
+ #define RB_SC_WMODE S_IWUSR
+ #define RB_SC_RMODE S_IRUSR
+#else
+ #define RB_SC_HAS_WRITE_SUPPORT false
+ #define RB_SC_WMODE 0
+ #define RB_SC_RMODE S_IRUSR
+#endif
+
+/* ID values for software settings */
+#define RB_SCID_UART_SPEED 0x01 // u32*1
+#define RB_SCID_BOOT_DELAY 0x02 // u32*1
+#define RB_SCID_BOOT_DEVICE 0x03 // u32*1
+#define RB_SCID_BOOT_KEY 0x04 // u32*1
+#define RB_SCID_CPU_MODE 0x05 // u32*1
+#define RB_SCID_BIOS_VERSION 0x06 // str
+#define RB_SCID_BOOT_PROTOCOL 0x09 // u32*1
+#define RB_SCID_CPU_FREQ_IDX 0x0C // u32*1
+#define RB_SCID_BOOTER 0x0D // u32*1
+#define RB_SCID_SILENT_BOOT 0x0F // u32*1
+/*
+ * protected_routerboot seems to use tag 0x1F. It only works in combination with
+ * RouterOS, resulting in a wiped board otherwise, so it's not implemented here.
+ * The tag values are as follows:
+ * - off: 0x0
+ * - on: the lower halfword encodes the max value in s for the reset feature,
+ * the higher halfword encodes the min value in s for the reset feature.
+ * Default value when on: 0x00140258: 0x14 = 20s / 0x258= 600s
+ * See details here: https://wiki.mikrotik.com/wiki/Manual:RouterBOARD_settings#Protected_bootloader
+ */
+
+/* Tag values */
+
+#define RB_UART_SPEED_115200 0
+#define RB_UART_SPEED_57600 1
+#define RB_UART_SPEED_38400 2
+#define RB_UART_SPEED_19200 3
+#define RB_UART_SPEED_9600 4
+#define RB_UART_SPEED_4800 5
+#define RB_UART_SPEED_2400 6
+#define RB_UART_SPEED_1200 7
+#define RB_UART_SPEED_OFF 8
+
+/* valid boot delay: 1 - 9s in 1s increment */
+#define RB_BOOT_DELAY_MIN 1
+#define RB_BOOT_DELAY_MAX 9
+
+#define RB_BOOT_DEVICE_ETHER 0 // "boot over Ethernet"
+#define RB_BOOT_DEVICE_NANDETH 1 // "boot from NAND, if fail then Ethernet"
+#define RB_BOOT_DEVICE_CFCARD 2 // (not available in rbcfg)
+#define RB_BOOT_DEVICE_ETHONCE 3 // "boot Ethernet once, then NAND"
+#define RB_BOOT_DEVICE_NANDONLY 5 // "boot from NAND only"
+#define RB_BOOT_DEVICE_FLASHCFG 7 // "boot in flash configuration mode"
+#define RB_BOOT_DEVICE_FLSHONCE 8 // "boot in flash configuration mode once, then NAND"
+
+/*
+ * ATH79 CPU frequency indices.
+ * It is unknown if they apply to all ATH79 RBs, and some do not seem to feature
+ * the up levels (QCA955x), while U3 is presumably AR9344-only.
+ */
+#define RB_CPU_FREQ_IDX_ATH79_D2 (0 << 3)
+#define RB_CPU_FREQ_IDX_ATH79_D1 (1 << 3) // 0x8
+#define RB_CPU_FREQ_IDX_ATH79_N0 (2 << 3) // 0x10 - factory freq for many devices
+#define RB_CPU_FREQ_IDX_ATH79_U1 (3 << 3) // 0x18
+#define RB_CPU_FREQ_IDX_ATH79_U2 (4 << 3) // 0x20
+#define RB_CPU_FREQ_IDX_ATH79_U3 (5 << 3) // 0x28
+
+#define RB_SC_CRC32_OFFSET 4 // located right after magic
+
+static struct kobject *sc_kobj;
+static u8 *sc_buf;
+static size_t sc_buflen;
+static rwlock_t sc_bufrwl; // rw lock to sc_buf
+
+/* MUST be used with lock held */
+#define RB_SC_CLRCRC() *(u32 *)(sc_buf + RB_SC_CRC32_OFFSET) = 0
+#define RB_SC_GETCRC() *(u32 *)(sc_buf + RB_SC_CRC32_OFFSET)
+#define RB_SC_SETCRC(_crc) *(u32 *)(sc_buf + RB_SC_CRC32_OFFSET) = (_crc)
+
+struct sc_u32tvs {
+ const u32 val;
+ const char *str;
+};
+
+#define RB_SC_TVS(_val, _str) { \
+ .val = (_val), \
+ .str = (_str), \
+}
+
+static ssize_t sc_tag_show_u32tvs(const u8 *pld, u16 pld_len, char *buf,
+ const struct sc_u32tvs tvs[], const int tvselmts)
+{
+ const char *fmt;
+ char *out = buf;
+ u32 data; // cpu-endian
+ int i;
+
+ if (sizeof(data) != pld_len)
+ return -EINVAL;
+
+ read_lock(&sc_bufrwl);
+ data = *(u32 *)pld; // pld aliases sc_buf
+ read_unlock(&sc_bufrwl);
+
+ for (i = 0; i < tvselmts; i++) {
+ fmt = (tvs[i].val == data) ? "[%s] " : "%s ";
+ out += sprintf(out, fmt, tvs[i].str);
+ }
+
+ out += sprintf(out, "\n");
+ return out - buf;
+}
+
+static ssize_t sc_tag_store_u32tvs(const u8 *pld, u16 pld_len, const char *buf, size_t count,
+ const struct sc_u32tvs tvs[], const int tvselmts)
+{
+ int i;
+
+ if (sizeof(u32) != pld_len)
+ return -EINVAL;
+
+ for (i = 0; i < tvselmts; i++) {
+ if (sysfs_streq(buf, tvs[i].str)) {
+ write_lock(&sc_bufrwl);
+ *(u32 *)pld = tvs[i].val; // pld aliases sc_buf
+ RB_SC_CLRCRC();
+ write_unlock(&sc_bufrwl);
+ return count;
+ }
+ }
+
+ return -EINVAL;
+}
+
+struct sc_boolts {
+ const char *strfalse;
+ const char *strtrue;
+};
+
+static ssize_t sc_tag_show_boolts(const u8 *pld, u16 pld_len, char *buf,
+ const struct sc_boolts *bts)
+{
+ const char *fmt;
+ char *out = buf;
+ u32 data; // cpu-endian
+
+ if (sizeof(data) != pld_len)
+ return -EINVAL;
+
+ read_lock(&sc_bufrwl);
+ data = *(u32 *)pld; // pld aliases sc_buf
+ read_unlock(&sc_bufrwl);
+
+ fmt = (data) ? "%s [%s]\n" : "[%s] %s\n";
+ out += sprintf(out, fmt, bts->strfalse, bts->strtrue);
+
+ return out - buf;
+}
+
+static ssize_t sc_tag_store_boolts(const u8 *pld, u16 pld_len, const char *buf, size_t count,
+ const struct sc_boolts *bts)
+{
+ u32 data; // cpu-endian
+
+ if (sizeof(data) != pld_len)
+ return -EINVAL;
+
+ if (sysfs_streq(buf, bts->strfalse))
+ data = 0;
+ else if (sysfs_streq(buf, bts->strtrue))
+ data = 1;
+ else
+ return -EINVAL;
+
+ write_lock(&sc_bufrwl);
+ *(u32 *)pld = data; // pld aliases sc_buf
+ RB_SC_CLRCRC();
+ write_unlock(&sc_bufrwl);
+
+ return count;
+}
+static struct sc_u32tvs const sc_uartspeeds[] = {
+ RB_SC_TVS(RB_UART_SPEED_OFF, "off"),
+ RB_SC_TVS(RB_UART_SPEED_1200, "1200"),
+ RB_SC_TVS(RB_UART_SPEED_2400, "2400"),
+ RB_SC_TVS(RB_UART_SPEED_4800, "4800"),
+ RB_SC_TVS(RB_UART_SPEED_9600, "9600"),
+ RB_SC_TVS(RB_UART_SPEED_19200, "19200"),
+ RB_SC_TVS(RB_UART_SPEED_38400, "38400"),
+ RB_SC_TVS(RB_UART_SPEED_57600, "57600"),
+ RB_SC_TVS(RB_UART_SPEED_115200, "115200"),
+};
+
+/*
+ * While the defines are carried over from rbcfg, use strings that more clearly
+ * show the actual setting purpose (especially since the NAND* settings apply
+ * to both nand- and nor-based devices). "cfcard" was disabled in rbcfg: disable
+ * it here too.
+ */
+static struct sc_u32tvs const sc_bootdevices[] = {
+ RB_SC_TVS(RB_BOOT_DEVICE_ETHER, "eth"),
+ RB_SC_TVS(RB_BOOT_DEVICE_NANDETH, "flasheth"),
+ //RB_SC_TVS(RB_BOOT_DEVICE_CFCARD, "cfcard"),
+ RB_SC_TVS(RB_BOOT_DEVICE_ETHONCE, "ethonce"),
+ RB_SC_TVS(RB_BOOT_DEVICE_NANDONLY, "flash"),
+ RB_SC_TVS(RB_BOOT_DEVICE_FLASHCFG, "cfg"),
+ RB_SC_TVS(RB_BOOT_DEVICE_FLSHONCE, "cfgonce"),
+};
+
+static struct sc_boolts const sc_bootkey = {
+ .strfalse = "any",
+ .strtrue = "del",
+};
+
+static struct sc_boolts const sc_cpumode = {
+ .strfalse = "powersave",
+ .strtrue = "regular",
+};
+
+static struct sc_boolts const sc_bootproto = {
+ .strfalse = "bootp",
+ .strtrue = "dhcp",
+};
+
+static struct sc_boolts const sc_booter = {
+ .strfalse = "regular",
+ .strtrue = "backup",
+};
+
+static struct sc_boolts const sc_silent_boot = {
+ .strfalse = "off",
+ .strtrue = "on",
+};
+
+#define SC_TAG_SHOW_STORE_U32TVS_FUNCS(_name) \
+static ssize_t sc_tag_show_##_name(const u8 *pld, u16 pld_len, char *buf) \
+{ \
+ return sc_tag_show_u32tvs(pld, pld_len, buf, sc_##_name, ARRAY_SIZE(sc_##_name)); \
+} \
+static ssize_t sc_tag_store_##_name(const u8 *pld, u16 pld_len, const char *buf, size_t count) \
+{ \
+ return sc_tag_store_u32tvs(pld, pld_len, buf, count, sc_##_name, ARRAY_SIZE(sc_##_name)); \
+}
+
+#define SC_TAG_SHOW_STORE_BOOLTS_FUNCS(_name) \
+static ssize_t sc_tag_show_##_name(const u8 *pld, u16 pld_len, char *buf) \
+{ \
+ return sc_tag_show_boolts(pld, pld_len, buf, &sc_##_name); \
+} \
+static ssize_t sc_tag_store_##_name(const u8 *pld, u16 pld_len, const char *buf, size_t count) \
+{ \
+ return sc_tag_store_boolts(pld, pld_len, buf, count, &sc_##_name); \
+}
+
+SC_TAG_SHOW_STORE_U32TVS_FUNCS(uartspeeds)
+SC_TAG_SHOW_STORE_U32TVS_FUNCS(bootdevices)
+SC_TAG_SHOW_STORE_BOOLTS_FUNCS(bootkey)
+SC_TAG_SHOW_STORE_BOOLTS_FUNCS(cpumode)
+SC_TAG_SHOW_STORE_BOOLTS_FUNCS(bootproto)
+SC_TAG_SHOW_STORE_BOOLTS_FUNCS(booter)
+SC_TAG_SHOW_STORE_BOOLTS_FUNCS(silent_boot)
+
+static ssize_t sc_tag_show_bootdelays(const u8 *pld, u16 pld_len, char *buf)
+{
+ const char *fmt;
+ char *out = buf;
+ u32 data; // cpu-endian
+ int i;
+
+ if (sizeof(data) != pld_len)
+ return -EINVAL;
+
+ read_lock(&sc_bufrwl);
+ data = *(u32 *)pld; // pld aliases sc_buf
+ read_unlock(&sc_bufrwl);
+
+ for (i = RB_BOOT_DELAY_MIN; i <= RB_BOOT_DELAY_MAX; i++) {
+ fmt = (i == data) ? "[%d] " : "%d ";
+ out += sprintf(out, fmt, i);
+ }
+
+ out += sprintf(out, "\n");
+ return out - buf;
+}
+
+static ssize_t sc_tag_store_bootdelays(const u8 *pld, u16 pld_len, const char *buf, size_t count)
+{
+ u32 data; // cpu-endian
+ int ret;
+
+ if (sizeof(data) != pld_len)
+ return -EINVAL;
+
+ ret = kstrtou32(buf, 10, &data);
+ if (ret)
+ return ret;
+
+ if ((data < RB_BOOT_DELAY_MIN) || (RB_BOOT_DELAY_MAX < data))
+ return -EINVAL;
+
+ write_lock(&sc_bufrwl);
+ *(u32 *)pld = data; // pld aliases sc_buf
+ RB_SC_CLRCRC();
+ write_unlock(&sc_bufrwl);
+
+ return count;
+}
+
+static ssize_t sc_attr_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf);
+static ssize_t sc_attr_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count);
+
+/* Array of known tags to publish in sysfs */
+static struct sc_attr {
+ const u16 tag_id;
+ /* sysfs tag show attribute. Must lock sc_buf when dereferencing pld */
+ ssize_t (* const tshow)(const u8 *pld, u16 pld_len, char *buf);
+ /* sysfs tag store attribute. Must lock sc_buf when dereferencing pld */
+ ssize_t (* const tstore)(const u8 *pld, u16 pld_len, const char *buf, size_t count);
+ struct kobj_attribute kattr;
+ u16 pld_ofs;
+ u16 pld_len;
+} sc_attrs[] = {
+ {
+ .tag_id = RB_SCID_UART_SPEED,
+ .tshow = sc_tag_show_uartspeeds,
+ .tstore = sc_tag_store_uartspeeds,
+ .kattr = __ATTR(uart_speed, RB_SC_RMODE|RB_SC_WMODE, sc_attr_show, sc_attr_store),
+ }, {
+ .tag_id = RB_SCID_BOOT_DELAY,
+ .tshow = sc_tag_show_bootdelays,
+ .tstore = sc_tag_store_bootdelays,
+ .kattr = __ATTR(boot_delay, RB_SC_RMODE|RB_SC_WMODE, sc_attr_show, sc_attr_store),
+ }, {
+ .tag_id = RB_SCID_BOOT_DEVICE,
+ .tshow = sc_tag_show_bootdevices,
+ .tstore = sc_tag_store_bootdevices,
+ .kattr = __ATTR(boot_device, RB_SC_RMODE|RB_SC_WMODE, sc_attr_show, sc_attr_store),
+ }, {
+ .tag_id = RB_SCID_BOOT_KEY,
+ .tshow = sc_tag_show_bootkey,
+ .tstore = sc_tag_store_bootkey,
+ .kattr = __ATTR(boot_key, RB_SC_RMODE|RB_SC_WMODE, sc_attr_show, sc_attr_store),
+ }, {
+ .tag_id = RB_SCID_CPU_MODE,
+ .tshow = sc_tag_show_cpumode,
+ .tstore = sc_tag_store_cpumode,
+ .kattr = __ATTR(cpu_mode, RB_SC_RMODE|RB_SC_WMODE, sc_attr_show, sc_attr_store),
+ }, {
+ .tag_id = RB_SCID_BIOS_VERSION,
+ .tshow = routerboot_tag_show_string,
+ .tstore = NULL,
+ .kattr = __ATTR(bios_version, RB_SC_RMODE, sc_attr_show, NULL),
+ }, {
+ .tag_id = RB_SCID_BOOT_PROTOCOL,
+ .tshow = sc_tag_show_bootproto,
+ .tstore = sc_tag_store_bootproto,
+ .kattr = __ATTR(boot_proto, RB_SC_RMODE|RB_SC_WMODE, sc_attr_show, sc_attr_store),
+ }, {
+ .tag_id = RB_SCID_BOOTER,
+ .tshow = sc_tag_show_booter,
+ .tstore = sc_tag_store_booter,
+ .kattr = __ATTR(booter, RB_SC_RMODE|RB_SC_WMODE, sc_attr_show, sc_attr_store),
+ }, {
+ .tag_id = RB_SCID_SILENT_BOOT,
+ .tshow = sc_tag_show_silent_boot,
+ .tstore = sc_tag_store_silent_boot,
+ .kattr = __ATTR(silent_boot, RB_SC_RMODE|RB_SC_WMODE, sc_attr_show, sc_attr_store),
+ },
+ // TODO CPU_FREQ
+};
+
+static ssize_t sc_attr_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ const struct sc_attr *sc_attr;
+ const u8 *pld;
+ u16 pld_len;
+
+ sc_attr = container_of(attr, typeof(*sc_attr), kattr);
+
+ if (!sc_attr->pld_len)
+ return -ENOENT;
+
+ pld = sc_buf + sc_attr->pld_ofs; // pld aliases sc_buf -> lock!
+ pld_len = sc_attr->pld_len;
+
+ return sc_attr->tshow(pld, pld_len, buf);
+}
+
+static ssize_t sc_attr_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ const struct sc_attr *sc_attr;
+ const u8 *pld;
+ u16 pld_len;
+
+ if (!RB_SC_HAS_WRITE_SUPPORT)
+ return -EOPNOTSUPP;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ sc_attr = container_of(attr, typeof(*sc_attr), kattr);
+
+ if (!sc_attr->tstore)
+ return -EOPNOTSUPP;
+
+ if (!sc_attr->pld_len)
+ return -ENOENT;
+
+ pld = sc_buf + sc_attr->pld_ofs; // pld aliases sc_buf -> lock!
+ pld_len = sc_attr->pld_len;
+
+ return sc_attr->tstore(pld, pld_len, buf, count);
+}
+
+/*
+ * Shows the current buffer status:
+ * "clean": the buffer is in sync with the mtd data
+ * "dirty": the buffer is out of sync with the mtd data
+ */
+static ssize_t sc_commit_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ const char *str;
+ char *out = buf;
+ u32 crc;
+
+ read_lock(&sc_bufrwl);
+ crc = RB_SC_GETCRC();
+ read_unlock(&sc_bufrwl);
+
+ str = (crc) ? "clean" : "dirty";
+ out += sprintf(out, "%s\n", str);
+
+ return out - buf;
+}
+
+/*
+ * Performs buffer flushing:
+ * This routine expects an input compatible with kstrtobool().
+ * - a "false" input discards the current changes and reads data back from mtd.
+ * - a "true" input commits the current changes to mtd.
+ * If there is no pending changes, this routine is a no-op.
+ * Handling failures is left as an exercise to userspace.
+ */
+static ssize_t sc_commit_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct mtd_info *mtd;
+ struct erase_info ei;
+ size_t bytes_rw, ret = count;
+ bool flush;
+ u32 crc;
+
+ if (!RB_SC_HAS_WRITE_SUPPORT)
+ return -EOPNOTSUPP;
+
+ read_lock(&sc_bufrwl);
+ crc = RB_SC_GETCRC();
+ read_unlock(&sc_bufrwl);
+
+ if (crc)
+ return count; // NO-OP
+
+ ret = kstrtobool(buf, &flush);
+ if (ret)
+ return ret;
+
+ mtd = get_mtd_device_nm(RB_MTD_SOFT_CONFIG); // TODO allow override
+ if (IS_ERR(mtd))
+ return -ENODEV;
+
+ write_lock(&sc_bufrwl);
+ if (!flush) // reread
+ ret = mtd_read(mtd, 0, mtd->size, &bytes_rw, sc_buf);
+ else { // crc32 + commit
+ /*
+ * CRC32 is computed on the entire buffer, excluding the CRC
+ * value itself. CRC is already null when we reach this point,
+ * so we can compute the CRC32 on the buffer as is.
+ * The expected CRC32 is Ethernet FCS style, meaning the seed is
+ * ~0 and the final result is also bitflipped.
+ */
+
+ crc = ~crc32(~0, sc_buf, sc_buflen);
+ RB_SC_SETCRC(crc);
+
+ /*
+ * The soft_config partition is assumed to be entirely contained
+ * in a single eraseblock.
+ */
+
+ ei.addr = 0;
+ ei.len = mtd->size;
+ ret = mtd_erase(mtd, &ei);
+ if (!ret)
+ ret = mtd_write(mtd, 0, mtd->size, &bytes_rw, sc_buf);
+
+ /*
+ * Handling mtd_write() failure here is a tricky situation. The
+ * proposed approach is to let userspace deal with retrying,
+ * with the caveat that it must try to flush the buffer again as
+ * rereading the mtd contents could potentially read garbage.
+ * The rationale is: even if we keep a shadow buffer of the
+ * original content, there is no guarantee that we will ever be
+ * able to write it anyway.
+ * Regardless, it appears that RouterBOOT will ignore an invalid
+ * soft_config (including a completely wiped segment) and will
+ * write back factory defaults when it happens.
+ */
+ }
+ write_unlock(&sc_bufrwl);
+
+ if (ret)
+ goto mtdfail;
+
+ if (bytes_rw != sc_buflen) {
+ ret = -EIO;
+ goto mtdfail;
+ }
+
+ return count;
+
+mtdfail:
+ RB_SC_CLRCRC(); // mark buffer content as dirty/invalid
+ return ret;
+}
+
+static struct kobj_attribute sc_kattrcommit = __ATTR(commit, RB_SC_RMODE|RB_SC_WMODE, sc_commit_show, sc_commit_store);
+
+int __init rb_softconfig_init(struct kobject *rb_kobj)
+{
+ struct mtd_info *mtd;
+ size_t bytes_read, buflen;
+ const u8 *buf;
+ int i, ret;
+ u32 magic;
+
+ sc_buf = NULL;
+ sc_kobj = NULL;
+
+ // TODO allow override
+ mtd = get_mtd_device_nm(RB_MTD_SOFT_CONFIG);
+ if (IS_ERR(mtd))
+ return -ENODEV;
+
+ sc_buflen = mtd->size;
+ sc_buf = kmalloc(sc_buflen, GFP_KERNEL);
+ if (!sc_buf)
+ return -ENOMEM;
+
+ ret = mtd_read(mtd, 0, sc_buflen, &bytes_read, sc_buf);
+
+ if (ret)
+ goto fail;
+
+ if (bytes_read != sc_buflen) {
+ ret = -EIO;
+ goto fail;
+ }
+
+ /* Check we have what we expect */
+ magic = *(const u32 *)sc_buf;
+ if (RB_MAGIC_SOFT != magic) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* Skip magic and 32bit CRC located immediately after */
+ buf = sc_buf + (sizeof(magic) + sizeof(u32));
+ buflen = sc_buflen - (sizeof(magic) + sizeof(u32));
+
+ /* Populate sysfs */
+ ret = -ENOMEM;
+ sc_kobj = kobject_create_and_add(RB_MTD_SOFT_CONFIG, rb_kobj);
+ if (!sc_kobj)
+ goto fail;
+
+ rwlock_init(&sc_bufrwl);
+
+ /* Locate and publish all known tags */
+ for (i = 0; i < ARRAY_SIZE(sc_attrs); i++) {
+ ret = routerboot_tag_find(buf, buflen, sc_attrs[i].tag_id,
+ &sc_attrs[i].pld_ofs, &sc_attrs[i].pld_len);
+ if (ret) {
+ sc_attrs[i].pld_ofs = sc_attrs[i].pld_len = 0;
+ continue;
+ }
+
+ /* Account for skipped magic and crc32 */
+ sc_attrs[i].pld_ofs += sizeof(magic) + sizeof(u32);
+
+ ret = sysfs_create_file(sc_kobj, &sc_attrs[i].kattr.attr);
+ if (ret)
+ pr_warn(RB_SC_PR_PFX "Could not create %s sysfs entry (%d)\n",
+ sc_attrs[i].kattr.attr.name, ret);
+ }
+
+ /* Finally add the 'commit' attribute */
+ if (RB_SC_HAS_WRITE_SUPPORT) {
+ ret = sysfs_create_file(sc_kobj, &sc_kattrcommit.attr);
+ if (ret) {
+ pr_err(RB_SC_PR_PFX "Could not create %s sysfs entry (%d), aborting!\n",
+ sc_kattrcommit.attr.name, ret);
+ goto sysfsfail; // required attribute
+ }
+ }
+
+ pr_info("MikroTik RouterBOARD software configuration sysfs driver v" RB_SOFTCONFIG_VER "\n");
+
+ return 0;
+
+sysfsfail:
+ kobject_put(sc_kobj);
+ sc_kobj = NULL;
+fail:
+ kfree(sc_buf);
+ sc_buf = NULL;
+ return ret;
+}
+
+void __exit rb_softconfig_exit(void)
+{
+ kobject_put(sc_kobj);
+ kfree(sc_buf);
+}
projects / openwrt / staging / luka.git / commitdiff