[PATCH] board: rockchip: Add support for rk3588 MNT Reform2

[Quentin Schulz]

Hi Peter,

On 9/26/25 6:26 PM, Peter Robinson wrote:
> Hi Quentin,
> 
>> On 6/30/25 12:25 PM, Peter Robinson wrote:
[...]
>>> +CONFIG_DEFAULT_FDT_FILE="rockchip/rk3588-mnt-reform2"
>>
>> Shouldn't that end with .dtb?
> 
> Nope.

Interestingly we have a mix of some adding .dtb and some not:

$ git grep CONFIG_DEFAULT_FDT_FILE configs/ | grep -v dtb | wc -l
44
$ git grep CONFIG_DEFAULT_FDT_FILE configs/ | grep dtb | wc -l
244

Most notably, all Rockchip defconfigs add .dtb at the end.

The value of this Kconfig symbol is the content of the fdtfile 
environment variable, which seems to be expecting a .dtb-suffixed file?

See doc/develop/bootstd/overview.rst:

"""
fdtfile
     Name of the flattened device tree (FDT) file to load, e.g.
     "rockchip/rk3399-rockpro64.dtb"
"""

and doc/develop/distro.rst:

"""
fdtfile:
   Mandatory. the name of the DTB file for the specific board for instance
   the espressobin v5 board the value is 
"marvell/armada-3720-espressobin.dtb"
   while on a clearfog pro it is "armada-388-clearfog-pro.dtb" in the 
case of
   a board providing its firmware based DTB this value can be used to 
override
   the DTB with a different DTB. fdtfile will automatically be set for 
you if
   it matches the format ${soc}-${board}.dtb which covers most 32 bit 
use cases.
   AArch64 generally does not match as the Linux kernel put the dtb 
files under
   SoC vendor directories.
"""

so it seems like we are indeed expecting a .dtb-suffixed file.

boot/pxe_utils.c seems to be reconstructing fdtfile with a forced .dtb 
suffix (c.f. f4 variable when label->fdt isn't set in label_boot().

What am I missing?

Cheers,
Quentin