Hi list,
This is the second version of my RFC patchset to treat static UBI volumes as DM block devices, allowing users to access read-only filesystems (SquashFS, EROFS) contained within such volumes.
This is a rebased and updated version, as requested by Heiko.
Previously, we have agreed on a syntax, which my downstream is now starting to use: => ls ubi 0:rootfs /boot => ls ubi 0:2 /boot
This is still not yet ready for mainline inclusion, because the actual UBI DM access is happening in disk/part.c, which is not "clean" with the way the DM/legacy switching is currently plumbed. I'm still looking for guidance on how to name/implement block functions for looking up a *subvolume* block device by type+parentidx+{name,ID}.
Changes v1->v2: - Rebased onto next post-2023.10's release. - Fix NULL dereference caused by passing NULL to `blk_create_device` - Parse UBI index/volume numbers with `dectoul` instead of `hextoul`, to match Linux's behavior of treating these numbers as decimal. - Do not treat a valid decimal number as a volume name, even if the volume ID doesn't exist, to match Linux's behavior of always treating decimal numbers as volume IDs.
Cheers, Sam
Sam Edwards (4): mtd: ubi: register UBI attachments as DM devices mtd: ubi: bind block device driver for static volumes disk: part: fall-through if "ubi" requested but ubifs not mounted HACK: enable access to `ubi 0:volname` block devices
cmd/ubi.c | 11 +++ disk/part.c | 69 +++++++++++-- drivers/mtd/ubi/Makefile | 1 + drivers/mtd/ubi/ubi-uclass.c | 185 +++++++++++++++++++++++++++++++++++ include/dm/uclass-id.h | 1 + include/ubi_uboot.h | 5 + 6 files changed, 264 insertions(+), 8 deletions(-) create mode 100644 drivers/mtd/ubi/ubi-uclass.c