595 lines
25 KiB
Diff
595 lines
25 KiB
Diff
From 33e651e124d1f4fc3dabcc9b83da1fb7c52ce88c Mon Sep 17 00:00:00 2001
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From: Frank Wunderlich <[email protected]>
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Date: Sun, 6 Jul 2025 17:00:18 +0200
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Subject: [PATCH 48/84] add mtd-rw driver
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from https://github.com/jclehner/mtd-rw
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---
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drivers/mtd/Kconfig | 2 +
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drivers/mtd/Makefile | 2 +
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drivers/mtd/mtdrw/Kconfig | 8 +
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drivers/mtd/mtdrw/LICENSE | 339 ++++++++++++++++++++++++++++++++++++
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drivers/mtd/mtdrw/Makefile | 15 ++
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drivers/mtd/mtdrw/README.md | 25 +++
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drivers/mtd/mtdrw/mtd-rw.c | 132 ++++++++++++++
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7 files changed, 523 insertions(+)
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create mode 100644 drivers/mtd/mtdrw/Kconfig
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create mode 100644 drivers/mtd/mtdrw/LICENSE
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create mode 100644 drivers/mtd/mtdrw/Makefile
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create mode 100644 drivers/mtd/mtdrw/README.md
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create mode 100644 drivers/mtd/mtdrw/mtd-rw.c
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diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
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index 796a2eccbef0..7bd7ea0d5ddc 100644
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--- a/drivers/mtd/Kconfig
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+++ b/drivers/mtd/Kconfig
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@@ -222,4 +222,6 @@ source "drivers/mtd/ubi/Kconfig"
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source "drivers/mtd/hyperbus/Kconfig"
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+source "drivers/mtd/mtdrw/Kconfig"
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+
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endif # MTD
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diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
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index 593d0593a038..4c2437657a9c 100644
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--- a/drivers/mtd/Makefile
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+++ b/drivers/mtd/Makefile
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@@ -31,3 +31,5 @@ obj-y += chips/ lpddr/ maps/ devices/ nand/ tests/
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obj-$(CONFIG_MTD_SPI_NOR) += spi-nor/
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obj-$(CONFIG_MTD_UBI) += ubi/
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obj-$(CONFIG_MTD_HYPERBUS) += hyperbus/
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+
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+obj-y += mtdrw/
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diff --git a/drivers/mtd/mtdrw/Kconfig b/drivers/mtd/mtdrw/Kconfig
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new file mode 100644
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index 000000000000..a81af6f11b91
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--- /dev/null
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+++ b/drivers/mtd/mtdrw/Kconfig
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@@ -0,0 +1,8 @@
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+config MTD_RW
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+ tristate "Module to make all MTD partitions writeable"
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+ default n
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+ help
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+ Say M here to build a module which, upon loading, will make
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+ all read-only MTD partitions writeable. Do not say Y here.
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+
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+ If unsure, say N.
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diff --git a/drivers/mtd/mtdrw/LICENSE b/drivers/mtd/mtdrw/LICENSE
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new file mode 100644
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index 000000000000..23cb790338e1
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--- /dev/null
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+++ b/drivers/mtd/mtdrw/LICENSE
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@@ -0,0 +1,339 @@
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+ GNU GENERAL PUBLIC LICENSE
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+ Version 2, June 1991
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+
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+ Copyright (C) 1989, 1991 Free Software Foundation, Inc., <http://fsf.org/>
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+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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+ Everyone is permitted to copy and distribute verbatim copies
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+
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+ Preamble
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+ The licenses for most software are designed to take away your
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+freedom to share and change it. By contrast, the GNU General Public
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+software--to make sure the software is free for all its users. This
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+General Public License applies to most of the Free Software
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+using it. (Some other Free Software Foundation software is covered by
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+the GNU Lesser General Public License instead.) You can apply it to
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+your programs, too.
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+
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+ When we speak of free software, we are referring to freedom, not
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+ {signature of Ty Coon}, 1 April 1989
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+ Ty Coon, President of Vice
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diff --git a/drivers/mtd/mtdrw/Makefile b/drivers/mtd/mtdrw/Makefile
|
|
new file mode 100644
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|
index 000000000000..d1061ccf3a67
|
|
--- /dev/null
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|
+++ b/drivers/mtd/mtdrw/Makefile
|
|
@@ -0,0 +1,15 @@
|
|
+# Build module only if kernel supports MTD
|
|
+ifdef CONFIG_MTD
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+obj-m += mtd-rw.o
|
|
+endif
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+
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+KDIR ?= /lib/modules/$(shell uname -r)/build
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+
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+modules:
|
|
+ $(MAKE) -C $(KDIR) M=$$PWD modules
|
|
+
|
|
+modules_install:
|
|
+ $(MAKE) -C $(KDIR) M=$$PWD modules_install
|
|
+
|
|
+clean:
|
|
+ $(MAKE) -C $(KDIR) M=$$PWD clean
|
|
diff --git a/drivers/mtd/mtdrw/README.md b/drivers/mtd/mtdrw/README.md
|
|
new file mode 100644
|
|
index 000000000000..dc3b08894ae5
|
|
--- /dev/null
|
|
+++ b/drivers/mtd/mtdrw/README.md
|
|
@@ -0,0 +1,25 @@
|
|
+mtd-rw - Write-enabler for MTD partitions
|
|
+=========================================
|
|
+
|
|
+Sets the `MTD_WRITEABLE` flag on all MTD partitions that are marked readonly.
|
|
+When unloading, read-only partitions will be restored. This module is intended
|
|
+for embedded devices where the mtd partition layout may be hard-coded in the
|
|
+firmware. If, for some reason, you DO have to write to a read-only partition
|
|
+(which is often a bad idea), this module is the way to go.
|
|
+
|
|
+The module is currently limited to the first 64 partitions, but this
|
|
+should suffice for most purposes.
|
|
+
|
|
+Inspired by [email protected]:
|
|
+https://electronics.stackexchange.com/a/116133/97342
|
|
+
|
|
+Usage:
|
|
+```
|
|
+# insmod mtd-rw.ko i_want_a_brick=1
|
|
+# dmesg | grep mtd-rw
|
|
+[52997.620000] mtd-rw: mtd0: setting writeable flag
|
|
+[52997.630000] mtd-rw: mtd1: setting writeable flag
|
|
+[52997.640000] mtd-rw: mtd3: setting writeable flag
|
|
+[52997.650000] mtd-rw: mtd4: setting writeable flag
|
|
+[52997.660000] mtd-rw: mtd6: setting writeable flag
|
|
+```
|
|
diff --git a/drivers/mtd/mtdrw/mtd-rw.c b/drivers/mtd/mtdrw/mtd-rw.c
|
|
new file mode 100644
|
|
index 000000000000..706714d3db77
|
|
--- /dev/null
|
|
+++ b/drivers/mtd/mtdrw/mtd-rw.c
|
|
@@ -0,0 +1,132 @@
|
|
+/*
|
|
+ * mtd-rw - Make all MTD partitions writeable.
|
|
+ *
|
|
+ * Copyright (C) 2016 Joseph C. Lehner <[email protected]>
|
|
+ *
|
|
+ * This program is free software; you can redistribute it and/or modify
|
|
+ * it under the terms of the GNU General Public License as published by
|
|
+ * the Free Software Foundation; version 2 of the License.
|
|
+ *
|
|
+ * This program is distributed in the hope that it will be useful,
|
|
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
+ * GNU General Public License for more details.
|
|
+ *
|
|
+ * You should have received a copy of the GNU General Public License
|
|
+ * along with this program.
|
|
+ * If not, see <http://www.gnu.org/licenses/>.
|
|
+ */
|
|
+
|
|
+#include <linux/kernel.h>
|
|
+#include <linux/module.h>
|
|
+#include <linux/mtd/mtd.h>
|
|
+#include <linux/err.h>
|
|
+
|
|
+/*
|
|
+ * This module is intended for embedded devices where the mtd partition
|
|
+ * layout may be hard-coded in the firmware. If, for some reason, you
|
|
+ * DO have to write to a read-only partition (which is often a bad idea),
|
|
+ * this module is the way to go.
|
|
+ *
|
|
+ * The module is currently limited to the first 64 partitions, but this
|
|
+ * should suffice for most purposes.
|
|
+ *
|
|
+ * Inspired by [email protected]:
|
|
+ * https://electronics.stackexchange.com/a/116133/97342
|
|
+ */
|
|
+
|
|
+#ifndef MODULE
|
|
+#error "Must be compiled as a module."
|
|
+#endif
|
|
+
|
|
+#define MOD_WARNING KERN_WARNING "mtd-rw: "
|
|
+#define MOD_INFO KERN_INFO "mtd-rw: "
|
|
+#define MOD_ERR KERN_ERR "mtd-rw: "
|
|
+
|
|
+#define MTD_MAX (8 * sizeof(unlocked))
|
|
+
|
|
+static uint64_t unlocked = 0;
|
|
+static unsigned mtd_last = 0;
|
|
+
|
|
+static bool i_want_a_brick = false;
|
|
+module_param(i_want_a_brick, bool, S_IRUGO);
|
|
+MODULE_PARM_DESC(i_want_a_brick, "Make all partitions writeable");
|
|
+
|
|
+static int set_writeable(unsigned n, bool w)
|
|
+{
|
|
+ struct mtd_info *mtd = get_mtd_device(NULL, n);
|
|
+ int err;
|
|
+
|
|
+ if (IS_ERR(mtd)) {
|
|
+ if (PTR_ERR(mtd) != -ENODEV || !w) {
|
|
+ printk(MOD_ERR "mtd%d: error %ld\n", n, PTR_ERR(mtd));
|
|
+ }
|
|
+ return PTR_ERR(mtd);
|
|
+ }
|
|
+
|
|
+ err = -EEXIST;
|
|
+
|
|
+ if (w && !(mtd->flags & MTD_WRITEABLE)) {
|
|
+ printk(MOD_INFO "mtd%d: setting writeable flag\n", n);
|
|
+ mtd->flags |= MTD_WRITEABLE;
|
|
+ err = 0;
|
|
+ } else if (!w && (mtd->flags & MTD_WRITEABLE)) {
|
|
+ printk(MOD_INFO "mtd%d: clearing writeable flag\n", n);
|
|
+ mtd->flags &= ~MTD_WRITEABLE;
|
|
+ err = 0;
|
|
+ }
|
|
+
|
|
+ put_mtd_device(mtd);
|
|
+ return err;
|
|
+}
|
|
+
|
|
+static int __init mtd_rw_init(void)
|
|
+{
|
|
+ int i, err;
|
|
+
|
|
+ if (!i_want_a_brick) {
|
|
+ printk(MOD_ERR "must specify i_want_a_brick=1 to continue\n");
|
|
+ return -EINVAL;
|
|
+ }
|
|
+
|
|
+ for (i = 0; i < MTD_MAX; ++i) {
|
|
+ err = set_writeable(i, true);
|
|
+ if (!err) {
|
|
+ unlocked |= (1 << i);
|
|
+ } else if (err == -ENODEV) {
|
|
+ break;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ if (i == MTD_MAX) {
|
|
+ printk(MOD_WARNING "partitions beyond mtd%d are ignored\n", i - 1);
|
|
+ }
|
|
+
|
|
+ if (!unlocked) {
|
|
+ printk(MOD_INFO "no partitions to unlock\n");
|
|
+ return -ENODEV;
|
|
+ }
|
|
+
|
|
+ mtd_last = i;
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+static void __exit mtd_rw_exit(void)
|
|
+{
|
|
+ unsigned i;
|
|
+
|
|
+ for (i = 0; i < mtd_last; ++i) {
|
|
+ if (unlocked & (1 << i)) {
|
|
+ set_writeable(i, false);
|
|
+ }
|
|
+ }
|
|
+}
|
|
+
|
|
+module_init(mtd_rw_init);
|
|
+module_exit(mtd_rw_exit);
|
|
+
|
|
+MODULE_LICENSE("GPL");
|
|
+MODULE_AUTHOR("Joseph C. Lehner <[email protected]>");
|
|
+MODULE_DESCRIPTION("Write-enabler for MTD partitions");
|
|
+MODULE_VERSION("1");
|
|
--
|
|
2.30.2
|
|
|