Add --arch flag to pack mode of vbutil_kernel

Add --arch flag to pack mode of vbutil_kernel

When --arch flag is not x86, x86-only operations in pack mode are
turned off so that we can reuse vbutil_kernel to generate kernel partition
images for other targets, such as arm.

See CL:6538014 for its application.

BUG=chromium-os:3790
TEST=Run "emerge vboot_reference" successfully

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=0376203

[Bill Richardson, 2011-02-17 17:36:28]

LGTM

[Randall Spangler, 2011-02-17 20:25:36]

LGTM

Though I'd tend to call the param --no-x86 so it looks like a boolean --x86 flag
(like shutils).  That'll be nicer if later we decide to make the x86 stuff
default to off (and --x86 turns it on).

[Che-Liang Chiou, 2011-02-21 11:12:30]

Hi,

Reviewer of another CL (6538014) suggests changing --notx86 to --arch. PTAL.
Thanks.

On 2011/02/17 20:25:36, Randall Spangler wrote:
> LGTM
> 
> Though I'd tend to call the param --no-x86 so it looks like a boolean --x86
flag
> (like shutils).  That'll be nicer if later we decide to make the x86 stuff
> default to off (and --x86 turns it on).

[Randall Spangler, 2011-02-21 17:17:41]

On Mon, Feb 21, 2011 at 3:12 AM, <clchiou@chromium.org> wrote:

> Hi,
>
> Reviewer of another CL (6538014) suggests changing --notx86 to --arch.
> PTAL.
>

That's an even better idea.  Then --arch=x86 is the default and includes
those sections, and --arch=arm doesn't.

- Randall


> Thanks.
>
> On 2011/02/17 20:25:36, Randall Spangler wrote:
>
>> LGTM
>>
>
>  Though I'd tend to call the param --no-x86 so it looks like a boolean
>> --x86
>>
> flag
>
>> (like shutils).  That'll be nicer if later we decide to make the x86 stuff
>> default to off (and --x86 turns it on).
>>
>
>
>
> http://codereview.chromium.org/6538015/
>

[Che-Liang Chiou, 2011-02-22 02:20:40]

Thanks. I will make x86 default.

On 2011/02/21 17:17:41, Randall Spangler wrote:
> On Mon, Feb 21, 2011 at 3:12 AM, <mailto:clchiou@chromium.org> wrote:
> 
> > Hi,
> >
> > Reviewer of another CL (6538014) suggests changing --notx86 to --arch.
> > PTAL.
> >
> 
> That's an even better idea.  Then --arch=x86 is the default and includes
> those sections, and --arch=arm doesn't.
> 
> - Randall
> 
> 
> > Thanks.
> >
> > On 2011/02/17 20:25:36, Randall Spangler wrote:
> >
> >> LGTM
> >>
> >
> >  Though I'd tend to call the param --no-x86 so it looks like a boolean
> >> --x86
> >>
> > flag
> >
> >> (like shutils).  That'll be nicer if later we decide to make the x86 stuff
> >> default to off (and --x86 turns it on).
> >>
> >
> >
> >
> > http://codereview.chromium.org/6538015/
> >