is there still any need PPC checking for "chosen at 0"?

Michael Ellerman mpe at ellerman.id.au
Wed Aug 8 23:58:57 AEST 2018


"Robert P. J. Day" <rpjday at crashcourse.ca> writes:
>   given that there are no .dts files in the current kernel code base
> that define the node name "/chosen at 0" instead of the proper "/chosen",

A good portion of PPC machines get their device tree from firmware, not
from a dts that's in the kernel tree, so that's not a good indication.

> is there any need for arch/powerpc/boot/oflib.c to still make this
> test:
>
>         chosen = of_finddevice("/chosen");
>         if (chosen == (phandle) -1) {
>                 chosen = of_finddevice("/chosen at 0");   <--- this
>                 if (chosen == (phandle) -1) {
>                         printf("no chosen\n");
>                         return 0;
>                 }
>         }
>
> are there still PPC machines that require the recognition of
> "/chosen at 0"?

It was added by Paul in:

66a45dd3620e ("powerpc: Make COFF zImages for old 32-bit powermacs")

So presumably there's an old powermac somewhere that needs it.

Given it's basically 2 extra lines of code I'd be inclined to leave it
alone.

cheers


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