[U-Boot] [PATCH 2/2] [rfc] support booting arm64 android image

[Andy Yan]

Hi:

2017-07-13 15:33 GMT+08:00 Bin Chen <bin.chen at linaro.org>:

> Hi Tom,
>
> Thanks for the review.
>
> On 13 July 2017 at 04:25, Tom Rini <trini at konsulko.com> wrote:
>
> > On Tue, Jul 11, 2017 at 03:56:04PM +1000, Bin Chen wrote:
> >
> > > It's my understanding that we are supposed to use booti, instead of
> > bootm,
> > > for arm64 image. But booti lacks of android image support. Bootm has
> > > the andriod image support but lack of the arm64 image handling.
> > >
> > > So, what is suppose the right way of booting an android arm64 image?
> > > or, should we create a separate command?
> > >
> > > This patch is an invitation for that discussion.
> > >
> > > It *hacked* the booti command and it aslo assume the dtb is in the
> > second area
> > > of android boot image. It also has other belives like u-boot should be
> > > in control of where to put the kernnel/ramdisk/dtb images so it ignores
> > > the value specified in the android images.
> > >
> > > Signed-off-by: Bin Chen <bin.chen at linaro.org>
> >
> > So, booti is very much for the "Image" format described in the Linux
> > kernel in Documentation/arm64/booting.txt.  One can (and people have)
> > used bootm on aarch64 for "uImage" style kernels and FIT kernels, and I
> > would see being able to boot an aarch64 Android image with bootm as the
> > way to go forward.
>
>
> Are you suggesting that we should use bootm path, instead of booti?
>
> I have two questions regarding this:
>
> 1. currently arm64 kernel don't have a uImage kernel target. And I'm not
> sure
>  if adding that will be something that is wanted and/or sensible.
>
>
  It seems that bootm doesn't always require a uImage kernel. Consider we
use bootm to boot a ARM32 based android boot.img.
we pack the zImage in boot.img directly, without make it to uImage .

> 2. bootm path doesn't have the logic that is currently in the booti, such
> as the
> kernel relocation.
>
> Also, one other question raised during internal discussion was why the
> booti
> was created in the first place, if we could have had that implemented in
> the
> bootm path.
>
>
>
> > The analogy would be that we use bootm for Android
> > on arm not bootz.  Thanks!
> >
> > --
> > Tom
> >
>
>
>
> --
> Regards,
> Bin
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