[Lenny400] LetuxOS on SD card for MIPS JZ4780 CI20

[Paul Boddie]

On Friday 19. April 2019 14.27.16 H. Nikolaus Schaller wrote:
> 
> That looks interesting!
> 
> CONFIG_BUILTIN_DTB is mentioned on
> https://cateee.net/lkddb/web-lkddb/BUILTIN_DTB.html
> 
> but it is neither defined by ci20_defconfig nor letux_defconfig.

It isn't in ci20_defconfig, not even in the 3.18 kernel, but for some reason 
it is set in my .config.

> Here is the ci20_defconfig:
> 
> 	
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arc
> h/mips/configs/ci20_defconfig?h=v5.1-rc5
> 
> The latter defines CONFIG_MIPS_RAW_APPENDED_DTB by default!:
> 
> 	http://git.goldelico.com/?p=letux-kernel.git;a=blob;f=arch/mips/configs/let
> ux_defconfig;h=4e85d9a6b2bac0a96c14aaac36ad8e3fcf735b23;hb=202f2274f4ec7e82f
> 42634c3f3b2284ba23806a4

I may have put it there. :-)

> So it might simply suffice to append the .dtb manually... I think there is
> (was) some script to do that inside flash-nand for the GTA04. Yes, here:
> 
> 	http://git.goldelico.com/?p=letux-kernel.git;a=blob;f=Letux/root/flash-nand
> ;h=284c5c19d6e041d6adf883fd4f84f9fe5319e2e5;hb=refs/heads/letux-5.1-rc5#l274
> 
> Or if we do research there might be a kernel make option for that. I'll give
> it a try as soon as I find time for it.

In the 3.18 kernel for the CI20, there is this in arch/mips/Makefile:

----
# device-trees
core-$(CONFIG_BUILTIN_DTB) += arch/mips/boot/dts/

%.dtb %.dtb.S %.dtb.o: | scripts
        $(Q)$(MAKE) $(build)=arch/mips/boot/dts arch/mips/boot/dts/$@

PHONY += dtbs
dtbs: scripts
        $(Q)$(MAKE) $(build)=arch/mips/boot/dts dtbs
----

I suspect that this should be causing the device tree binary to be bundled.

Paul