NixOS on ARM/Teres-I
| Teres I | |
|---|---|
| Manufacturer | OLIMEX |
| Architecture | AArch64 |
| Bootloader | U-Boot |
| Boot order | To be confirmed |
| Maintainer | Thra11 |
The Teres I is a DIY laptop kit based on the Allwinner A64 SoC.
It can boot from SD or from the internal eMMC.
Status
Most functionality works in a generic aarch64 image using a recent kernel (tested 5.11 and 5.12).
Board-specific installation notes
Serial console
Details about the pinout for the headphone jack are available [1]. Serial output is enabled by writing 1 to GPIO 361.
Bluetooth
Bluetooth support for the Teres I is not yet included in linux. However, it can be made to work with a few modifications:
1. Enable support for Realtek bluetooth controllers in your chosen kernel:
nixpkgs.config.packageOverrides = pkgs: {
linux_5_11 = pkgs.linux_5_11.override {
extraConfig = ''
BT_HCIUART_RTL y
'';
kernelPatches = [ {
name = "arm64-dts-allwinner-a64-Enable-Bluetooth-on-Teres-I";
patch = ./0001-arm64-dts-allwinner-a64-Enable-Bluetooth-on-Teres-I.patch;
}
];
};
};
2. Add a section to the teres devicetree, arch/arm64/boot/dts/allwinner/sun50i-a64-teres-i.dts, to indicate that it has a realtek rtl8723bs bluetooth chip attached to uart1. This can be done either by patching the kernel sources, or as a device tree overlay:
&uart1 {
pinctrl-names = "default";
pinctrl-0 = <&uart1_pins>, <&uart1_rts_cts_pins>;
uart-has-rtscts;
status = "okay";
bluetooth {
compatible = "realtek,rtl8723bs-bt";
device-wake-gpios = <&r_pio 0 6 GPIO_ACTIVE_HIGH>; /* PL6 */
host-wake-gpios = <&r_pio 0 5 GPIO_ACTIVE_HIGH>; /* PL5 */
enable-gpios = <&r_pio 0 4 GPIO_ACTIVE_HIGH>; /* PL4 */
};
};
3. The package firmware-linux-nonfreecontains a blob which is suitable, rtl8723bs_config-OBDA8723.bin but it is suffixed with the ACPI ID. Since we are using a devicetree instead, linux expects it to be available as rtl8723bs_config.bin. We can achieve this by creating a simple package containing a symlink to the firmware file, and adding it to hardware.firmware in our NixOS configuration:
{ runCommandNoCC, firmwareLinuxNonfree }:
runCommandNoCC "teres-rtl8723bs-firmware-${firmwareLinuxNonfree.version}" {} ''
mkdir -p $out/lib/firmware/rtl_bt
ln -s ${firmwareLinuxNonfree}/lib/firmware/rtl_bt/rtl8723bs_config-OBDA8723.bin \
$out/lib/firmware/rtl_bt/rtl8723bs_config.bin
''
Known issues
- The keyboard firmware does not initialise in time to provide input to u-boot. An external USB keyboard can be used to change u-boot settings or choose which NixOS generation to boot.