[OE-core] [PATCH] kernel-arch.bbclass: Add xtensa and arc into valid_archs table

[Bystricky, Juro]

The single purpose of "map_kernel_arch" is to set 

export ARCH = "arch_xxx"

Presently, we must set ARCH even when building baremetal toolchains only, 
without any need to build kernel. However, in this case we may 
encounter a bogus error such as "cannot map arch_xxx to a linux kernel architecture".
The simplest way to avoid this is to place arch_xxx into the table
"valid_archs". (That was the main reason for the patch).

A better but more complex way would be to modify the code so
map_kernel_arch is not called at all when NOT building kernel or kernel
modules. This would also allow building baremetal cross-toolchains for arches
that don't have Linux kernels at all.

Another way to consider is perhaps just getting rid of the table
"valid_archs" entirely.

"map_kernel_arch" maps arch_aaa -> arch_xxx for some cases.
If there is no explicit mapping, then it could simply map 

arch_aaa->arch_aaa

resulting in export ARCH="arch_aaa"
There would be no error generated. If ARCH is not a valid
arch for a Linux kernel, we would encounter a build error at some point.
But that, I believe is the same case now if we try to build a kernel
with a valid kernel ARCH but not supported actively in OE or extended OE ecosystem.




> -----Original Message-----
> From: Khem Raj [mailto:raj.khem at gmail.com]
> Sent: Monday, October 17, 2016 4:40 PM
> To: Bystricky, Juro <juro.bystricky at intel.com>
> Cc: openembedded-core at lists.openembedded.org; jurobystricky at hotmail.com
> Subject: Re: [OE-core] [PATCH] kernel-arch.bbclass: Add xtensa and arc into
> valid_archs table
> 
> 
> > On Oct 11, 2016, at 9:31 AM, Juro Bystricky <juro.bystricky at intel.com>
> wrote:
> >
> > Both "arc" and "xtensa" are valid Linux architectures, add
> > them into valid_archs table.
> >
> > Signed-off-by: Juro Bystricky <juro.bystricky at intel.com>
> > ---
> > meta/classes/kernel-arch.bbclass | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/meta/classes/kernel-arch.bbclass b/meta/classes/kernel-
> arch.bbclass
> > index 8a4bef1..ea976c6 100644
> > --- a/meta/classes/kernel-arch.bbclass
> > +++ b/meta/classes/kernel-arch.bbclass
> > @@ -14,7 +14,7 @@ valid_archs = "alpha cris ia64 \
> >                parisc s390  v850 \
> >                avr32 blackfin \
> >                microblaze \
> > -               nios2"
> > +               nios2 arc xtensa”
> 
> there parisc etc as well so in essence patch is ok but I wonder if we
> should
> remove the arches we dont actively support in OE or extended OE ecosystem.
> 
> >
> > def map_kernel_arch(a, d):
> >     import re
> > --
> > 2.7.4
> >
> > --
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