On 05/23/2014 05:41 PM, Kevin Hilman wrote: > By default, add some padding to the DT blobs to facilitate later > patching. > > An example need for DTB patching is the need to modifiy the command > line on platforms where ATAGS are not (or cannot) be used to pass the > commandline. For example, we do not support a big-endian kernel > reading ATAGS from a little-endian u-boot, so the only way to pass a > command line in the DT. > > Also, without ATAG support (or if u-boot was built without > CONFIG_INITRD_TAG) the only way to pass an initrd is by adding an > initrd= option to command line (in the DT). > > Therefore, to facilitate adding to the DT command line directly in the > DTB, add some padding. > > Cc: Nicolas Pitre <nico@xxxxxxxxxx> > Cc: Stephen Warren <swarren@xxxxxxxxxxxxx> > Cc: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxx> > --- > I kinda pulled 64 bytes out of the air here since it's enough to add > some common things to the commandline like debug, earlyprink > initrd=<addr>,<size>, etc., but I'm certainlly not opposed to more > padding. Conceptually, Acked-by: Stephen Warren <swarren@xxxxxxxxxx> But I would expect a pad of something like 4KB to be more future-proof. U-Boot appears to use 4KB on ARM at least: ./arch/arm/dts/Makefile:37:DTC_FLAGS += -R 4 -p 0x1000 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
