Re: [Xen-devel] [PATCH V2 for-4.5] EFI: Always use EFI command line

[Roy Franz <roy.franz@xxxxxxxxxx>]

On Sat, Oct 25, 2014 at 2:06 AM, Ian Campbell <Ian.Campbell@xxxxxxxxxx> wrote:
> On Fri, 2014-10-24 at 16:41 -0700, Roy Franz wrote:
>>   (I'm not sure how I'm supposed to refer to to docs/misc/efi.markdown in
>>    the booting.txt.  Should I assume that it will be processed to html
>>    and refrence it that way?)
>
> This stuff kinda sucks because it all depends on where you build and
> install to etc. What you've done in naming the file as it appears in the
> source is fine. Other places use a reference to the canonical online
> copy at http://xenbits.xen.org/docs/unstable/ which is fine too I think.
>
>> @@ -104,4 +106,6 @@ and really not meant to be used together with the 
>> `-cfg=` command line option.
>>  Filenames must be specified relative to the location of the EFI binary.
>>
>>  Extra options to be passed to Xen can also be specified on the command line,
>> -following a `--` separator option.
>> +following a `--` separator option.
>
> Will grub automatically insert this "--" marker? Or is there some
> special handling in Xen when none of -cfg/-help/-videothing are present?
> (Doesn't look to be the case)
>
> Ian.
>

I'm not sure what GRUB should do.  I think that the root of the
problem is that the command line
given to Xen when booted as an "Image" file is different than when it
is booted as an EFI application.
In the Image case, the entire string is processed by Xen itself, while
in the EFI boot case, only the
portions after a "--" separator are processed by Xen, the stuff before
that is consumed by the EFI boot
code.  Switching between and EFI and Image boot in GRUB would either
mean the user changing
the command line, or GRUB doing some magic/heuristics to fix things up
behind the scenes.  Neither
of these seems like a great solution.  As I understand it, Fu's GRUB
work is only supporting EFI boot
of Xen for arm64, so we only have one case to consider, but if booting
an Image format Xen on arm64
is going to be supported in GRUB in the future then this is something
that we will have to deal with.

Jan - do you know how this command line handling in GRUB for x86 is
handled?  I would think that x86
would have the same issue with the command line.

Roy

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel