FreeBSD on the NanoPi NEOLTS

The NanoPi NEOLTS is a SBC from FriendlyElec that uses the Allwinner H3 SOC. The NanoPi NEOLTS has a nice selection of hardware including 100Mbit Ethernet, 3 USB Ports and a bunch of exposed GPIO.

FreeBSD on the NanoPi uses GENERICSD image. This image requires a bootloader to be added before it will work. We can prepare a single image to be copied to many SD cards by using a memory disk as an intermediate step.

We need to:

Get the latest GENERICSD card image snapshot
Install the correct boot loader pkg
Create a memory disk
Copy the GENERICSD image to memory disk
Copy the bootloader to the memory disk
Mount the root partition of the sd card image
Copy the programs and files we need for the tutorial to the sd card

The latest image is as I write is 13 CURRENT from 20190829:

$ fetch ftp://ftp.freebsd.org/pub/FreeBSD/snapshots/arm/armv7/ISO-IMAGES/13.0/FreeBSD-13.0-CURRENT-arm-armv7-GENERICSD-20190829-r351591.img.xz

We have to decompress the image before we can use it

$ xz -d FreeBSD-13.0-CURRENT-arm-armv7-GENERICSD-20190829-r351591.img.xz

Each u-boot bootloader platform has its own package, currently there are 46 different bootloaders in the FreeBSD ports system. We want the u-boot for the nanopi_neo (our target).

$ pkg search nanopi     
u-boot-nanopi-neo2-2019.07     Cross-build das u-boot for model nanopi-neo2
u-boot-nanopi_a64-2019.07      Cross-build das u-boot for model nanopi_a64
u-boot-nanopi_m1plus-2019.07   Cross-build das u-boot for model nanopi_m1plus
u-boot-nanopi_neo-2019.07      Cross-build das u-boot for model nanopi_neo
u-boot-nanopi_neo_air-2019.07  Cross-build das u-boot for model nanopi_neo_air

# pkg install u-boot-nanopi_neo-2019.07

The u-boot-nanopi_neo package contains the binary bootloader we need in u-boot-sunxi-with-spl.bin

$ pkg info -l u-boot-nanopi_neo-2019.07

u-boot-nanopi_neo-2019.07:
    /usr/local/share/licenses/u-boot-nanopi_neo-2019.07/GPLv2
    /usr/local/share/licenses/u-boot-nanopi_neo-2019.07/LICENSE
    /usr/local/share/licenses/u-boot-nanopi_neo-2019.07/catalog.mk
    /usr/local/share/u-boot/u-boot-nanopi_neo/README
    /usr/local/share/u-boot/u-boot-nanopi_neo/boot.scr
    /usr/local/share/u-boot/u-boot-nanopi_neo/metadata
    /usr/local/share/u-boot/u-boot-nanopi_neo/u-boot-sunxi-with-spl.bin

With the GENERICSD image and the bootloader we need to create the memory disk image we will use for staging. First we need to create a large enough backing file.

$ truncate -s 8G nanopi.img
# mdconfig -f nanopi.img
md0

Now we can dd the GENERICSD image to the memory disk

# dd if=FreeBSD-13.0-CURRENT-arm-armv7-GENERICSD-20190829-r351591.img of=/dev/md0 bs=1m

We need to dd the bootloader to the start of the SD card, i.e. the entire device and not a partition.

# dd if=/usr/local/share/u-boot/u-boot-nanopi_neo/u-boot-sunxi-with-spl.bin of=/dev/da0 bs=1k seek=8 conv=sync

With the memory disk attached we can interact with the image file as if it were a real USB drive or SD card.

$ gpart show md0
=>      63  16777153  md0  MBR  (8.0G)
        63      2016       - free -  (1.0M)
      2079    102312    1  fat32lba  [active]  (50M)
    104391   6187041    2  freebsd  (3.0G)
   6291432  10485784       - free -  (5.0G)

We can mount the root partition of the SD card and modify or add any files we wish:

# mount /dev/md0sa mnt

When we are done changing things we have to disconnect the memory disk:

# sudo mdconfig -d -u md0

Finally we can copy the memory disk to a real sd card using dd :

# sudo dd if=nanopi.img of=/dev/da0 bs=1m