OpenBSD on PinePhone Pro: First Impression

August 15, 2023

Disclaimer #

OpenBSD does not support PinePhone Pro yet and there are real risks involved in running it on your PinePhone Pro now, as such, I do not recommand anyone to do that. You might fry your device due to unsupported power management IC and in a worse case the battery might catch fire due to unconfigured/untested charging safety features.

The purpose of this post is to document how to install OpenBSD on arm64 platforms not fully supported by OpenBSD, and much of this post is not PinePhone-specific, if you intend to follow what documented here, please be mindful about the risks and apply common sense.

Overview #

• OpenBSD installer cannot be used on bare metal if you want to install OpenBSD to an sdcard, because of insufficiant hardware support. However, it’s possible to install OpenBSD to a virtual machine and then transfer the installed system to a SD card to boot from

• This post assumes you have a PinePhone Pro running Mobian with KVM properly configured, and an sdcard to transfer the installed system to

• As for now the only way to interact with the running system is via a serial console cable, wired and wireless network are not supported, same for screen, keyboard, and USB host mode

• Jump to Support Status to see what work (not much)

Prepare Disk Image #

To make full use of the sdcard, we will create a disk image with size equal to our sdcard. We can find precise size of the sdcard with fdisk on Mobian:

mobian$ echo p | sudo fdisk /dev/mmcblk1

A line similar to above should appear, showing the size of sdcard in bytes:

Disk /dev/mmcblk1: 29.72 GiB, 31914983424 bytes, 62333952 sectors

We can now create our disk image:

mobian$ qemu-img create -f qcow2 openbsd.vm.qcow2 31914983424

Bootstrap via virtual machine #

Installing OpenBSD on VM is relatively strightforward, get the minirootXX.img from OpenBSD mirror (at the moment I’m using miniroot73.img), and follow instruction from my other post

Add support files #

A freshly installed OpenBSD/arm64 VM is not bootable on bare metal, to make it bootable, we will need:

• Device Tree Blob (DTB) for PinePhone Pro, which describes the hardware environment
  • OpenBSD’s dtb package is compiled from Linux source tree, you can see how it is compiled here
• Support files for uboot, extracted from installer image

(I’m not sure if all the uboot files are needed, but it’s easy to extract them all)

This can be done from the VM we prepared:

Create mount point for operating on disk image #

vm# mkdir /mnt/{img,disk}

Prepare dtb and installer image #

vm# pkg_add dtb
vm# ftp https://cdn.openbsd.org/pub/OpenBSD/snapshots/arm64/miniroot73.img

Prepare and mount boot partition of installer image #

vm# vnconfig vnd0 miniroot73.img

vm# mount /dev/vnd0i /mnt/img/

Mount VM boot partition #

vm# mount /dev/sd0i /mnt/disk/

Copy files from installer boot partition to VM boot partition #

vm# cp -r /mnt/img/* /mnt/disk/

Copy DTB #

vm# cp /usr/local/share/dtb/arm64/rockchip/rk3399-pinephone-pro.dtb /mnt/disk/

Clean up #

vm# umount /mnt/disk/
vm# umount /mnt/img/
vm# vnconfig -u vnd0

Disable ohci #

ohci controller is not yet supported by OpenBSD on this device, and the existing driver can prevent the kernel from booting, before the root problem is addressed, we can disable ohci driver in kernel to workaround this.

vm# config -ef /bsd                                                                                                         

ukc> find ohci                                                                                                              
167 ohci* at pci* dev -1 function -1 flags 0x0                                                                              
236 ohci* at apldc*|agintc*|ampintc*|qcdwusb*|imxsrc*|imxdwusb*|mvmdio*|rktcphy*|rkpinctrl*|rkgrf*|rkdwusb*|hidwusb*|amldwus
b*|syscon*|sxisyscon*|simplebus*|mainbus0 early 0 flags 0x0                                                                 
413 ohci* at acpi0 addr -1 flags 0x0                                                                                        
ukc> disable 236                                                                                                            
236 ohci* disabled                                                                                                          
ukc> quit                                                     
Saving modified kernel.               

vm# shutdown -hp now

Write image to SD card #

Make sure you VM is properly shutdown, and your sdcard is at /dev/mmcblk1, then write the VM image to the sdcard.

mobian$ sudo qemu-img dd -f qcow2 -O raw if=openbsd.vm.qcow2 of=/dev/mmcblk1 bs=20M

Boot OpenBSD from Tow-boot #

To boot OpenBSD from the sdcard with Tow-boot:

• Insert sdcard into PinePhone Pro
• Then flip the DIP switch 6 (the rightmost, labeled Headphone) to enable serial access
• Connect a serial cable and open a console session, the example uses cu(1) since I’m using OpenBSD, but minicom can also work, towboot uses 115200 as baudrate but other u-boot build might differ

$ doas cu -s 115200 -l /dev/cuaU0

Something similar to the following output can help you confirm your serial connection is working:

U-Boot TPL 2021.10 (Oct 04 2021 - 15:09:26)                                                         
Channel 0: LPDDR4, 50MHz                                                                            
BW=32 Col=10 Bk=8 CS0 Row=15 CS1 Row=15 CS=2 Die BW=16 Size=2048MB                                  
Channel 1: LPDDR4, 50MHz                                                                            
BW=32 Col=10 Bk=8 CS0 Row=15 CS1 Row=15 CS=2 Die BW=16 Size=2048MB                                  
256B stride                                                                                         
lpddr4_set_rate: change freq to 400000000 mhz 0, 1                                                  
lpddr4_set_rate: change freq to 800000000 mhz 1, 0                                                  
Trying to boot from BOOTROM                                                                         
Returning to boot ROM...   

• Repeatedly press ESC to trigger tow-boot’s boot menu, select Boot from SD

                          Boot from eMMC                                        
                          Boot from SD                                          
                          Boot from USB                                         
                          Boot from PXE                                         
                          Boot from DHCP                                        
                          Boot from (sf0)                                       
                                                                                
                          Rescan USB                                            
                          Firmware Console                                      
                                                                                
                          Reboot                                                
                          Shutdown                                              
                         _          

• Something silmilar to the following should indicate OpenBSD is booting, and a login prompt will appear soon

boot>                                                                                               
booting sd0a:/bsd: 10625552+2504232+292520+843464 [792195+91+1216848+729496]=0x13b2240
[ using 2739408 bytes of bsd ELF symbol table ]                                                     
Copyright (c) 1982, 1986, 1989, 1991, 1993                                                          
        The Regents of the University of California.  All rights reserved.                          
Copyright (c) 1995-2023 OpenBSD. All rights reserved.  https://www.OpenBSD.org                      
                                                  
OpenBSD 7.3-current (GENERIC.MP) #2182: Thu Jul  6 15:02:37 MDT 2023                                
    deraadt@arm64.openbsd.org:/usr/src/sys/arch/arm64/compile/GENERIC.MP                            
real mem  = 4088885248 (3899MB)                                                                     
avail mem = 3883520000 (3703MB)

Support status #

dmesg #

Full dmesg and other hardware info is available from PinePhone Pro installation report