mtd: core: set ROOT_DEV for partitions marked as rootfs in DT

This adds support for "linux,rootfs" binding that is used to mark flash
partition containing rootfs. It's useful for devices using device tree
that don't have bootloader passing root info in cmdline.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221022211318.32009-2-zajec5@gmail.com
This commit is contained in:
Rafał Miłecki 2022-10-22 23:13:18 +02:00 committed by Miquel Raynal
parent 2b9a31d762
commit 26422ac78e

View file

@ -28,6 +28,7 @@
#include <linux/leds.h>
#include <linux/debugfs.h>
#include <linux/nvmem-provider.h>
#include <linux/root_dev.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
@ -737,6 +738,17 @@ int add_mtd_device(struct mtd_info *mtd)
not->add(mtd);
mutex_unlock(&mtd_table_mutex);
if (of_find_property(mtd_get_of_node(mtd), "linux,rootfs", NULL)) {
if (IS_BUILTIN(CONFIG_MTD)) {
pr_info("mtd: setting mtd%d (%s) as root device\n", mtd->index, mtd->name);
ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
} else {
pr_warn("mtd: can't set mtd%d (%s) as root device - mtd must be builtin\n",
mtd->index, mtd->name);
}
}
/* We _know_ we aren't being removed, because
our caller is still holding us here. So none
of this try_ nonsense, and no bitching about it