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

[Bin Chen]

Andy,

On 14 July 2017 at 17:30, Andy Yan <andyshrk at gmail.com> wrote:

> 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 .
>

You are right!


> 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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>>
>
>


-- 
Regards,
Bin