Linux needs to know what to use as root device. On embedded devices with
flash the only common way to specify that is cmdline & root= parameter.
That solution works with U-Boot which is Linux & cmdline aware but isn't
available with all market bootloaders. Also that method is fragile:
1. Requires specific probing order on multi-flash devices
2. Uses hardcoded partitions indexes
A lot of devices use different partitioning methods. It may be
"fixed-partitions" or some dynamic partitioning (e.g. based on parts
table). For such cases allow "linux,rootfs" property to mark correct
flash partition.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221022211318.32009-1-zajec5@gmail.com
Document new partition nodes that declare only the label/name instead
of the reg used to provide an OF node for partition registred at runtime
by parsers. This is required for nvmem system to declare and detect
nvmem-cells.
With these special partitions, the reg / offset is not required and a
'partition-' prefix is needed.
The node name with the 'partition-' prefix stripped, is used to match
the partition allocated by the parser at runtime and the parser will
provide reg and offset of the mtd.
If the partition to match contains invalid char for a node name, the
label binding can be used to declare the partition name.
NVMEM will use the data from the parser and provide the NVMEM cells
declared in the DTS, "connecting" the dynamic partition with a
static declaration of cells in them.
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220622010628.30414-2-ansuelsmth@gmail.com
Single partition binding is quite common and may be:
1. Used by multiple parsers
2. Extended for more specific cases
Move it to separated file to avoid code duplication.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
