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

[David Vrabel <david.vrabel@citrix.com>]

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?

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.

> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> ---
>  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.