Re: [Xen-staging] [xen staging] ARM: parse separate DT properties for different commandlines

[Andre Przywara <andre.przywara@linaro.org>]

On 09/18/2013 10:47 PM, Ian Campbell wrote:
> On Tue, 2013-09-17 at 14:48 +0000, patchbot@xen.org wrote:
>> commit a8992d62362e0755d3a1929b059769bc3343135d
>> Author:     Andre Przywara <andre.przywara@linaro.org>
>> AuthorDate: Fri Sep 13 13:49:34 2013 +0100
>> Commit:     Ian Campbell <ian.campbell@citrix.com>
>> CommitDate: Tue Sep 17 15:29:18 2013 +0100
>>
>>      ARM: parse separate DT properties for different commandlines
>>
>>      Currently we use the chosen/bootargs property as the Xen commandline
>>      and rely on xen,dom0-bootargs for Dom0. However this brings issues
>>      with bootloaders, which usually build bootargs by bootscripts for a
>>      Linux kernel - and not for the entirely different Xen hypervisor.
>>
>>      Introduce a new possible device tree property "xen,xen-bootargs"
>>      explicitly for the Xen hypervisor and make the selection of which to
>>      use more fine grained:
>>      - If xen,xen-bootargs is present, it will be used for Xen.
>>      - If xen,dom0-bootargs is present, it will be used for Dom0.
>>      - If xen,xen-bootargs is _not_ present, but xen,dom0-bootargs is,
>>        bootargs will be used for Xen. Like the current situation.
>>      - If no Xen specific properties are present, bootargs is for Dom0.
>>      - If xen,xen-bootargs is present, but xen,dom0-bootargs is missing,
>>        bootargs will be used for Dom0.
>
>
> So this doesn't seem to be working like I expected...
>
> I have a "bootargs" which contains my hypervisor bootargs, I have
> neither xen,xen-bootargs nor xen,dom0-bootargs. dom0 args are in the
> module bootargs property.
>
> But Xen isn't seeing a command line.

The same experience I had yesterday. Using the explicit xen,xen-bootargs 
for the time being works, though.
I am not sure if that due to that module node patch of mine, which also 
uses bootargs, though one level deeper. This may be triggered by one of 
Julien's DTB patches.

I will look into this this afternoon.

Regards,
Andre.

> Is my configuration wrong or is
> this supposed to work as it used to? I suppose the missing logic is to
> take into account whether the dom0 bootargs are in a module?
>
> FYI I'm seeing this on fastmodle with bootwrapper (from my xenbits arm32
> branch).
>
>> @@ -261,7 +261,12 @@ const char *device_tree_bootargs(const void *fdt)
>>       if ( node < 0 )
>>           return NULL;
>>
>> -    prop = fdt_get_property(fdt, node, "bootargs", NULL);
>> +    prop = fdt_get_property(fdt, node, "xen,xen-bootargs", NULL);
>> +    if ( prop == NULL )
>> +    {
>> +        if (fdt_get_property(fdt, node, "xen,dom0-bootargs", NULL))
>> +            prop = fdt_get_property(fdt, node, "bootargs", NULL);
>> +    }
>
>
>