[Tinkerphones] CI20 - was Re: New LetuxOS Kernels and some tricks and thoughts

[Paul Boddie]

On Tuesday 11. June 2019 08.14.49 H.  Nikolaus Schaller wrote:
> 
> > Am 09.06.2019 um 18:01 schrieb Paul Boddie <paul at boddie.org.uk>:
> > 
> > Ignoring the investigations into configuration and deployment tools, I did
> > manage to compile an upstream kernel for the CI20 today. Choosing the
> > 5.1.8 kernel, on the CI20 itself, I did the usual...
> > 
> > make ci20_defconfig
> > make
> > make uImage
> > 
> > Installing the uImage to /boot and rebooting actually worked without any
> > problems.
> 
> Great!

Actually, I rather spoke too soon. Rebooting succeeded, but a later cold boot 
failed: the device didn't start flashing its activity LEDs and wasn't 
reachable over the network.

Maybe there are some things that don't work in the upstream kernel that don't 
affect a reboot, or maybe systemd does some "helpful" things to simulate a 
reboot that I didn't know about. (It's always worthwhile to speculate about 
systemd and other "opinionated" software doing "helpful" stuff.)

> You could also try the latest
> 
> http://git.goldelico.com/?p=letux-kernel.git;a=shortlog;h=refs/heads/letux-5
> .1.8
> 
> with letux_defconfig.
> 
> The main differences are
> * adds your JZ4730 code (but does not make use it, obviously)
> * some diffs in the defconfig
> * prepared to build pvrsrv.ko
> 
> > I was able to ssh into the CI20 and find it over the network again!
> 
> Yes, Ethernet and ssh seems to work.

I do actually wonder if there isn't some very basic initialisation that does 
not work. Maybe it is related to the flash memory issues described on the 
ci20(-dev) mailing lists. So perhaps I will start the kernel with the UART 
cable attached and see what is reported.

[...]

> What I have observed that it is not working:
> * USB
> * HDMI
> * Camera
> * PVR/SGX (obviously)
> * untested: Audio
> * untested: Infrared (?). LED0..3, SW1
> * untested: Wireless
> 
> Does any of these work for you?

I'll have to investigate. I also looked at Mathieu's separate linux-ci20 
repository, but the tip of that didn't manage to build, complaining about 
rules to make various clock-related files.

Paul