Re: [PATCH v2 4/4] arm64: update the introduction of xen boot commands in docs/grub.texi

[Andrei Borzenkov]

On Fri, Feb 26, 2016 at 8:59 AM, Fu Wei <address@hidden> wrote:
>>>>> address@hidden xen_module
>>>>>
>>>>> address@hidden Command xen_linux file [arguments]
>>>>> -Load a dom0 kernel image for xen hypervisor at the booting process of 
>>>>> xen.
>>>>> address@hidden Command xen_module [--nounzip] file [arguments]
>>>>> +Load a module for xen hypervisor at the booting process of xen.
>>>>> The rest of the line is passed verbatim as the module command line.
>>>>> +Each module will be identified by the order in which the modules are 
>>>>> added.
>>>>> +The 1st module: dom0 kernel image
>>>>> +The 2nd module: dom0 ramdisk
>>>>> +All subsequent modules: UNKNOW
>>>>> @end deffn
>>>>
>>>> Hmm ... from previous discussion I gathered that Xen can detect module
>>>> type. What if there is no initrd for dom0? How can subsequent modules be
>>>
>>> Now , Xen detect module type by the order. (at least on ARM64).
>>> I think i386 is using Multiboot(2) protocol, so maybe this order is
>>> nothing to do with i386.
>>>
>>
>> Then we have obvious problem with your XSM patch 
>> (http://savannah.gnu.org/bugs/?43420) - XSM may land as the first module. 
>> That's actually something to solve on Xen side I think. It's just that so 
>> far we had just kernel and initrd, so that was non issue.
>
> Oh, did you mean Wei Liu's patch?
>
> I guess XSM may land as the third module (or the module after linux
> kernel, if you don't have initrd)
>
> Yes, agree. (That's actually something to solve on Xen side)
>
> I guess xen can get xsm from a special initrd. so for now there is not
> big problem on xsm.
>
> Please correct me if I misunderstand something. :-)
>
> Thanks!
>
> Back to this patch, is that OK for you, or any suggestion?  Thanks !
>

Yes, as this is dedicated Xen loader we should document this mandatory
order - first module must be kernel image, second module must be
initrd. I do not think we need to mention possibility to load more
than two modules until there is clear understanding how it can be done
without initrd.