NixOS on Pinecube (Early work in progress)

Build an SD card image with ./build.sh. Prebuilt image here (last updated 2020-10-27). Decompress and flash with:

$ cat ./result/sd-image/nixos-sd-image-21.03pre-git-armv7l-linux.img.zst | zstd -d | dd of=/dev/sdX bs=1024

It should be accessible over UART2 pins (see pinout on wiki) or SSH.

Username: nixos
Password: nixos

Additional Notes

Recording from CSI camera:

Streaming via rtmp:

Run a RTMP server on a machine on the network (assuming at 192.168.1.200).

On pinecube

$ media-ctl --set-v4l2 '"ov5640 1-003c":0[fmt:UYVY8_2X8/640x480@1/15]'
$ ffmpeg -s 640x480 -r 15 -i /dev/video0 -vcodec flv -f flv rtmp://192.168.1.200/live/pinecube

On receiving machine:

$ mpv "rtmp://192.168.1.200/live/pinecube" --profile=low-latency --cache-secs=1

Activating IR LEDs:

$ echo 1 > /sys/class/leds/pine64\:ir\:led1/brightness
$ echo 1 > /sys/class/leds/pine64\:ir\:led2/brightness

GPIO:

https://linux-sunxi.org/GPIO

$ cat /sys/kernel/debug/pinctrl/1c20800.pinctrl/pinmux-pins

gives information about pin numbering and what pins already claimed for other things

Enabling/disabling IR-cut filter

# Export gpio, set direction
$ echo 45 > /sys/class/gpio/export
$ echo out > /sys/class/gpio/gpio45/direction

# 1 to enable, 0 to disable
$ echo 1 > /sys/class/gpio/gpio45/value

Passive IR detection

# Export gpio, set direction
$ echo 199 > /sys/class/gpio/export
$ echo in > /sys/class/gpio/gpio199/direction

# Returns 1 for presence, 0 for none
$ cat /sys/class/gpio/gpio199/value

SPI NOR

In Linux, dmesg error: spi-nor spi0.0: unrecognized JEDEC id bytes: 0b 40 18 0b 40 18 The published schematic says it's a GD5F4GQ4UCYIG, however the label on the pinecube I have is for an XT25F128B. And this matches the JEDEC bytes reported in Linux.

SPI Boot

Run nix-build -A firmware-installer. Then,

$ dd if=result/firmware-installer-image.img of=/dev/sdX bs=1024

Then, use the menu option available over UART2 to install u-boot to the SPI.

I initially flashed a bad u-boot, which caused me to be unable to boot from MMC or even FEL. I was able to force the Pinecube to load into FEL by grounding the SPI0_MISO pin. Then, I could boot into u-boot and erase the SPI, returning the Pinecube to factory condition.

Ethernet

Working fine in linux, and now also u-boot with patch derived from: https://lists.denx.de/pipermail/u-boot/2020-May/413924.html S3 datasheet says it supports up to 1000Mbit, but we only have a 100Mbit PHY: H1601CG Maybe this is for easier PoE support?

USB

Not working in linux or u-boot. dmesg reports: supply vcc not found, using dummy regulator

WIFI

iwlist wlan0 scan worked fine. Stopped working after starting wpa_supplicant. Dmesg errors:

Oct 19 06:11:31 nixos wpa_supplicant[926]: Successfully initialized wpa_supplicant
Oct 19 06:11:32 nixos kernel: sunxi-mmc 1c10000.mmc: data error, sending stop command
Oct 19 06:11:32 nixos kernel: sunxi-mmc 1c10000.mmc: send stop command failed

Audio

Is not in currently in DTB at all. Maybe use sun7i-a20 as example. It has a "codec" block. See the S3 manual, grep for I2S/PCM.

Power Supply

See /sys/class/power_supply/axp20x-ac. See /sys/class/power_supply/axp20x-battery/{status,capacity}. Green LED if power is on. Red LED if battery is charging.

bhhaskin/pinecube-nixos