From 26422ac78e9d8767bd4aabfbae616b15edbf6a1b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= Date: Sat, 22 Oct 2022 23:13:18 +0200 Subject: [PATCH] mtd: core: set ROOT_DEV for partitions marked as rootfs in DT MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20221022211318.32009-2-zajec5@gmail.com --- drivers/mtd/mtdcore.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include @@ -748,6 +749,17 @@ 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