Re: [Xen-devel] [PATCH 16/16] arm: use /chosen/module1-args for domain 0 command line

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Thu, 2012-09-06 at 15:19 +0100, David Vrabel wrote:
> On 03/09/12 14:30, Ian Campbell wrote:
> > Ideally this would use module1-args iff the kernel came from
> > module1-{start,end} and the existing xen,dom0-bootargs if the kernel
> > came from flash, but this approach is simpler and has the sme effect
> > in practice.
> 
> Is module1-args defined in a spec somewhere?

Nope, I made it up as a PoC. I described it a little bit in the 0/16
mail.

> If the DT has xen,dom0-bootargs followed by module1-args you will end up
> with two bootargs nodes.  Suggest preferring the first one found and
> discard the other.

Yes.

> 
> > Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> > ---
> >  xen/arch/arm/domain_build.c |   23 ++++++++++++++++++++---
> >  1 files changed, 20 insertions(+), 3 deletions(-)
> > 
> > diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> > index e96ed10..2b65637 100644
> > --- a/xen/arch/arm/domain_build.c
> > +++ b/xen/arch/arm/domain_build.c
> > @@ -88,6 +88,8 @@ static int write_properties(struct domain *d, struct 
> > kernel_info *kinfo,
> >  {
> >      int prop;
> >  
> > +    int had_mod1_args = 0;
> > +
> >      for ( prop = fdt_first_property_offset(fdt, node);
> >            prop >= 0;
> >            prop = fdt_next_property_offset(fdt, prop) )
> > @@ -104,15 +106,30 @@ static int write_properties(struct domain *d, struct 
> > kernel_info *kinfo,
> >          prop_len  = fdt32_to_cpu(p->len);
> >  
> >          /*
> > -         * In chosen node: replace bootargs with value from
> > -         * xen,dom0-bootargs.
> > +         * In chosen node:
> > +         *
> > +         * * replace bootargs with value from module1-args, falling
> > +         *   back to xen,dom0-bootargs if not present.
> > +         * * remove all other module*.
> >           */
> >          if ( device_tree_node_matches(fdt, node, "chosen") )
> >          {
> >              if ( strcmp(prop_name, "bootargs") == 0 )
> >                  continue;
> > -            if ( strcmp(prop_name, "xen,dom0-bootargs") == 0 )
> > +            if ( strncmp(prop_name, "module", strlen("module")) == 0 )
> > +                 continue;
> 
> Clearer to write this as:
> 
>     if ( strncmp(prop_name, "module", strlen("module")) == 0 )
>         if ( strcmp(prop_name, "module1-args") == 0 )
>         {
>             prop_name = "bootargs";
>             had_mod1_args = 1;
>         }
>         else
>             continue;
>     }
> 
> > +            if ( strcmp(prop_name, "xen,dom0-bootargs") == 0 )
> > +            {
> > +                if ( had_mod1_args )
> > +                    continue;
> > +                else
> > +                    prop_name = "bootargs";
> > +            }
> >          }
> >          /*
> >           * In a memory node: adjust reg property.
> 



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