[Automated-testing] Looking for a Debian kernel provisioning solution

[Rees, Kevron]

On Fri, Jan 26, 2018 at 12:38 PM,  <Tim.Bird at sony.com> wrote:
>
>
>> -----Original Message-----
>> From: Rees, Kevron
>> On Wed, Jan 24, 2018 at 2:21 PM, Bird, Timothy <Tim.Bird at sony.com> wrote:
>> > So, I want to test LTS kernels on a MinnowBoard Turbot....
>> >
>> > I'm looking for a board farm solution that can handle
>> > building a mainline (or LTS) kernel, and deploy it to the MinnowBoard,
>> > and reboot the board to a Linux shell prompt.
> ...
>
>> We use jenkins to build real-time LTS kernels with yocto, deploy them
>> to minnowboard turbots (mbt) using lava, and run tests on them.  For
>> the lava side, we set the mbt to boot from efi network and we have
>> dnsmasq setup to serve up a grub bootloader.  Lava gives it a
>> temporary kernel and initramfs which lava uses to flash the image with
>> real-time kernel onto a USB flash disk.  Lava reboots the board into
>> grub again, and lava tells grub to chainload boot the newly installed
>> image from USB.  Once the image is booted, lava runs a series of
>> tests.
>
> Thanks for this information.  This is interesting.  I didn't realize
> 1) you could boot grub from the network, and 2)
> grub could boot from a USB flash disk.
>
>>
>> Tim Orling is going to give a session on this setup at ELC.  Let me
>> know if you have any questions.
> That's now on my list of ELC sessions to definitely attend!
>
> I'll have to look up efi netboot and dnsmasq.
>
> Does LAVA control grub over the serial console?
>

Yes.  So either the board itself has to be able to output console
information over serial, or grub has to be configured to do so.  I
haven't personally done grub yet.  It's possible and it's on my list
of things to figure out since we have some boards that do not have a
bios that supports serial output.

> Does the grub for mbt have to be specially built for this, or is this
> a feature of a grub binary that's already available?  That is,
> does the default grub that comes in Intel images have
> support for serial console?
>

Grub has to be built with network support (and serial support if you
use that).  We actually used a grub net boot efi file from ubuntu.

> Does LAVA already have the kernel and initramfs (pre-built) that I can
> just grab, or is this something I have to build myself?
>

They do.  We built our own, however.  It just needs to have network
support, wget and dd.  We built ours with bmaptool also since it's
faster at flashing than dd.

> Is this sequence of operations upstreamed anywhere?  Could I find
> it in the LAVA repos, or is this Intel custom stuff?
>

Everything except for the lava device-type are upstream.  We had to
modify the x86-grub device type to make it work with this usb flash
disk workflow.  We are working on upstreaming this new x86 device type
with corresponding lava test job examples.

It is also possible you can supply your kernel and initramfs and run
tests on the initramfs in memory.  That is a popular workflow with
lava.  We needed to install to USB because I/O operations affect
real-time latency in real life and we wanted our tests to reflect
reality as much as possible.

> Thanks for any information you can provide.
>  -- Tim
>