[SLOF] [PATCH] Remove dependency on cpu/@0 for booting

[Nikunj A Dadhania]

Segher Boessenkool <segher at kernel.crashing.org> writes:

> On Wed, Jul 27, 2016 at 12:06:06PM +0530, Nikunj A Dadhania wrote:
>> Segher Boessenkool <segher at kernel.crashing.org> writes:
>> 
>> > On Wed, Jul 27, 2016 at 09:47:47AM +0530, Nikunj A Dadhania wrote:
>> >>  \ Fixup timebase frequency from device-tree
>> >>  : fixup-tbfreq
>> >> -    " /cpus/@0" find-device
>> >> +    " /cpus" find-device
>> >> +    get-node child ?dup 0= IF ABORT" start-cpu not found" THEN
>> >> +    set-node
>> >
>> > ABORT" has an IF built in.  It also empties the stack, so this is just
>> >
>> >    get-node child dup 0= ABORT" start-cpu not found"
>> 
>> Sure.

i understood the IF part, but why not ?dup ?

> Well, the original code is incorrect: if there happens to be a zero next
> on stack, it will not abort, and your stack is unbalanced.  Whoops.

" /cpus" find-device ( )
get-node             ( node )
child                ( 0 | child-node )
?dup                 ( 0 | child-node child-node )
0= ABORT" start-cpu not found " ( child-node )
set-node


>
>> > What guarantees this finds the "start-cpu"?
>> 
>> QEMU does not allow to remove last CPU.
>
> But that is not the same thing?

Dont get you, can you please elaborate?

Regards
Nikunj