[Letux-kernel] playing with PinePhone - rootfs, kernel etc.

[H. Nikolaus Schaller]

> Am 14.12.2019 um 13:23 schrieb H. Nikolaus Schaller <hns at goldelico.com>:
> 
> 
>> Am 14.12.2019 um 13:16 schrieb H. Nikolaus Schaller <hns at goldelico.com>:
>> 
>> The biggest problem was to find out where the µSD slot is :)
>> 
>> You have to pop open the full back cover and then there is a tiny combined µSIM and µSD reader near the battery.
>> 
>> Then I looked up where to get a bootable Linux. I did choose Ubuntu Touch:
>> https://wiki.pine64.org/index.php/PinePhone#Ubuntu_Touch
>> 
>> I just did:
>> 
>> root at letux:~# wget -O - https://ci.ubports.com/job/rootfs/job/rootfs-pinephone/lastBuild/artifact/ubuntu-touch-pinephone.img.gz | gunzip | cat >/dev/sdb
>> 
>> and then the µSD looks like:
>> 
>> root at letux:~# ls -l /media/letux/ROOTFS
>> total 92
>> drwxr-xr-x   2 root root  4096 Dec 14 07:30 bin
>> drwxr-xr-x   2 root root  4096 Dec 14 07:59 boot
>> drwxr-xr-x   4 root root  4096 Dec 14 07:23 dev
>> drwxr-xr-x 109 root root  4096 Dec 14 08:00 etc
>> drwxr-xr-x   3 root root  4096 Dec 14 07:30 home
>> drwxr-xr-x  19 root root  4096 Dec 14 07:58 lib
>> drwx------   2 root root 16384 Dec 14 08:00 lost+found
>> drwxr-xr-x   2 root root  4096 Dec 14 07:21 media
>> drwxr-xr-x   2 root root  4096 Dec 14 07:21 mnt
>> drwxr-xr-x   3 root root  4096 Dec 14 07:29 opt
>> drwxr-xr-x   2 root root  4096 Apr 12  2016 proc
>> drwx------   2 root root  4096 Dec 14 07:30 root
>> drwxr-xr-x   8 root root  4096 Dec 14 07:29 run
>> drwxr-xr-x   2 root root  4096 Dec 14 07:30 sbin
>> drwxr-xr-x   2 root root  4096 Dec 14 07:56 script
>> drwxr-xr-x   2 root root  4096 Dec 14 07:21 srv
>> drwxr-xr-x   2 root root  4096 Feb  5  2016 sys
>> drwxrwxrwt   2 root root  4096 Dec 14 07:30 tmp
>> drwxr-xr-x  10 root root  4096 Dec 14 07:21 usr
>> drwxr-xr-x  11 root root  4096 Dec 14 07:30 var
>> root at letux:~# ls -l /media/letux/ROOTFS/boot/
>> total 19840
>> lrwxrwxrwx 1 root root      21 Dec 14 07:59 Image.gz -> Image.gz-5.4.0-pine64
>> -rw-r--r-- 1 root root 7454037 Dec 12 18:18 Image.gz-5.4.0-pine64
>> -rw-r--r-- 1 root root 3392125 Dec 12 18:18 System.map-5.4.0-pine64
>> -rw-r--r-- 1 root root     725 Dec 14 07:59 boot-dontbeevil.scr
>> -rw-r--r-- 1 root root     653 Dec 14 07:59 boot-dontbeevil.txt
>> -rw-r--r-- 1 root root     724 Dec 14 07:59 boot-pinephone.scr
>> -rw-r--r-- 1 root root     652 Dec 14 07:59 boot-pinephone.txt
>> -rw-r--r-- 1 root root     722 Dec 14 07:59 boot-pinetab.scr
>> -rw-r--r-- 1 root root     650 Dec 14 07:59 boot-pinetab.txt
>> -rw-r--r-- 1 root root     724 Dec 14 07:59 boot.scr
>> -rw-r--r-- 1 root root     628 Dec 14 07:59 boot.txt
>> -rw-r--r-- 1 root root  158964 Dec 12 18:18 config-5.4.0-pine64
>> lrwxrwxrwx 1 root root      33 Dec 14 07:59 dtb -> /usr/lib/linux-image-5.4.0-pine64
>> -rw-r--r-- 1 root root 4634987 Dec 14 07:59 initrd.img
>> -rw-r--r-- 1 root root 4634987 Dec 14 07:59 initrd.img-5.4.0-pine64
>> root at letux:~# 
>> 
>> Quite up-to date that it comes with a v5.4 kernel :)
>> 
>> U-Boot is very likely sitting in a hidden partition like for Udoo neo
>> or the Kobilino. fdisk says:
>> 
>> Device     Boot Start     End Sectors  Size Id Type
>> /dev/sdb1  *     1953 7812499 7810547  3.7G 83 Linux
>> 
>> So it does not look difficult to teach makesd to build a bootable µSD.
>> And teaching the Letux kernel to support CONFIG_ARCH_SUNXI.
>> 
>> My biggest barrier seems to be that it is ARM64 and I have no ARM64
>> toolchain in my kernel build setup... Maybe it can also run with 32 bit
>> like the RasPi?
>> 
>> Anyways I now need to test the µSD in the device.
> 
> Hm. Doesn't boot :(
> 
> Without µSD,pressing the power button or plugging in the USB-C
> cable makes the flash/torch light go on for a moment and makes
> the display show a red-green-blue bar for a moment. With µSD
> there is no reaction. Which means that it changes something.
> 
> Hm. Is there a serial console somewhere?

Yes, seems to exist:

http://files.pine64.org/doc/pinebook/guide/Pinebook_Earphone_Serial_Console_Developer_Guide.pdf

but it is not indicated that it is in serial mode during boot.