Hi,
this is an attempt to simplify the usage of user provided devicetree overlays. The idea is to let the user drop all desired .dtbo files into one directory (for instance on the EFI system partition), and U-Boot just applies all of them, with generic commands: => fdt move $fdtcontroladdr $fdt_addr_r => fdt resize => fdt apply-all mmc 0:1 overlays/
This would pick all files ending in .dtbo from the /overlays directory found on the first partition of the first MMC device. Ideally the device type, number and partition name would be provided by the distroboot scripting, so it checks the media it scans for boot scripts anyways.
Patch 1 fixes the "fdt move" operation in the sandbox. Since hostfs does not support fs_opendir/fs_readdir, which apply-all relies on, this cannot be tested in the sandbox, but I figured this bug is worth fixing anyway. Patch 2 avoids a redundant call to "fdt addr", if we just want to move (actually copy) the DTB. This is needed when we want to build on the control DT, since this might live in an area where it cannot be changed or grow enough. Patch 3 then implements the main attraction: It uses the U-Boot filesystem API to fs_readdir() the given directory, reads all files ending in ".dtbo" into memory, and tries to apply them to the working DT.
Please let me know what you think of the idea in general and the implementation in particular. The first two patches are actually bug fixes, and should be applied regardless.
Cheers, Andre
Andre Przywara (3): cmd: fdt: move: Use map_sysmem to convert pointers cmd: fdt: allow standalone "fdt move" fdt: introduce apply_all command
cmd/fdt.c | 123 +++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 108 insertions(+), 15 deletions(-)