inquiries on juno

inquiries on juno

[Sudeep Holla]

On 24/07/15 03:05, Zhaoyang Huang wrote:
> Dear ARM guys,
> I am HuangZhaoyang who is assignee engineer of linaro. I would like
> raise one problem which I find on juno board. Please help to check it
> when convenient. That is,
> The upstreaming kernel(v4.1 form torvalds's tree) can not boot up on
> juno. The terminal show bellowing logs and hung up then.
>
> Shell> Image dtb=juno/juno.dtb console=ttyAMA0,115200 rootwait
> root=/dev/sda2
> EFI stub: Booting Linux Kernel...
> EFI stub: Using DTB from command line
> EFI stub: Exiting boot services and installing virtual address map...
>

Please use the upstream dtb if you are not already. The downstream
kernel once carried a hack for memory mapped timer and had it enabled in
DT. However the upstream DTB doesn't enable the broken timer and it
should resolve your boot issue.

Regards,
Sudeep

inquiries on juno

[Sudeep Holla]

On 24/07/15 13:17, Zhaoyang Huang wrote:
> Dear Sudeep,
> Thanks for your quick feedback. I just use the dtb which I compiled by
> the upstreaming source code. So you mean I should use the upstreamed
> binary dtb file instead of the one which I compiled out?
>

No the one you have compiled should work. Try adding "earlycon" to the
command line and see if that works. You might have to apply[1] to get
earlycon working as Juno DTS specifies baud in stdout-path and currently
earlycon parsing has issues which [1] fixes.

Regards,
Sudeep

[1] https://lkml.org/lkml/2015/4/8/604

inquiries on juno

[Sudeep Holla]

On 27/07/15 11:16, Zhaoyang Huang wrote:
> Dear Sudeep,
> I applied the patch you mentioned on the git tree of v4.1 and get the
> error for[1]. Then I cherry-picked the commit[3] which I get from github
> where the missing function defined, while there is another error[2]. I
> am not sure if I am on the right way? Thank you!
>

I haven't tried that patch on v4.1, so I am not aware of all the
dependencies you may be missing. I have tried only on v4.2-rc* and it
works fine to me.

Other option would be to have "earlycon" in cmdline but remove baud in
stdout-path in Juno DT and see if it provides any log as where it's
getting hung during the boot.

But I repeat that v4.1 with defconfig and DT compiled from source just
works fine unless you are missing something in the firmware including 
DT. Hope that helps.

Regards,
Sudeep.

inquiries on juno

[Sudeep Holla]

On 27/07/15 14:08, Zhaoyang Huang wrote:
> Hi Sudeep,
> Thank you for further clarification. I will update the latest firmware
> and try again.
>
> BTW: Need I update the DTS file somewhere or just use the one get from
> the formal v4.1?
>

Mainline is always preferred :)

Regards,
Sudeep