View source for NixOS on ARM/OLIMEX Teres-A64

{{ARM/breadcrumb}}
<div class="infobox">
{|class="table"
!colspan="2" class="title"|OLIMEX Teres-A64
|-
|colspan="2"|[[File:Teres-A64-glamour.png|frameless|256px|The King Himself]]
|-
!Manufacturer
|OLIMEX, Ltd
|-
!Architecture
|AArch64
|-
!Bootloader
|Upstream U-Boot<ref>https://github.com/NixOS/nixpkgs/pull/240827</ref>
|-
!Boot order
|SD, eMMC
|-
!Maintainer
|[[User:KREYREN|KREYREN]]
|}
</div>

Teres-1 (often referred as teres-a64) is an open-source hardware and software netbook design based on the Allwinner A64 SoC.

It can boot from SD or from the included and slow af eMMC module (insane people use only).

== Status ==

Work In Progress..

The system is bootable and seems to work, but audio is broken and has rare graphical issues that are currently being investigated, note known issues below for building on Linux 6.0~6.1 resulting in broken display.

U-boot support [https://github.com/NixOS/nixpkgs/pull/240827 has been submitted on 2023-06-30, but not yet merged].

== Installation instructions ==

{{ARM/installation allwinner|variant=aarch64}}

=== Partitioning ===

All Allwinner SoCs will try to find a boot image at sector 16 (8KB) of an SD card, connected to the first MMC controller.[3] 

{{expansion|Details yet to be written..}}

==== MBR partition scheme ====

{{expansion|Installation instructions need to be written up to keep space for embedding the bootloader to the SPL.}}

==== GPT partition scheme ====

The [[NixOS_on_ARM/Allwinner_GPT_Installation|Allwinner GPT Installation]] instruction explains how to create a GPT partition table while allowing the isntallation of u-boot at the required offset.

== Serial console==

{{expansion|Details yet to be written..}}

== Compatibility notes ==

{| class="table arm-compatibility"
!colspan="2" style="background: #fafafa"| Mainline kernel
|-
! HDMI
|
* Hasn't been tested.
|}

=== Downstream kernel ===

{{note|Keep in mind that using non-upstream forks of the kernel always incurs some risk as far as security goes.}}

{{expansion|Find and document use of a kernel with the added capabilities.}}

== USB booting with u-boot ==

You will need to either have mainline U-Boot installed to the eMMC or to an SD card.

Stop the boot process when prompted (by pressing a key). Then, do the following:

<pre>
Hit any key to stop autoboot:  0
=> setenv boot_targets usb0
=> boot
</pre>

This sets the boot order for this boot only. U-Boot can boot (among others) either of the NixOS sd-image or EFI iso from USB.

== Known issues ==

Building the bootloader and the configuration on linux 6.0~6.1 will result in broken display rendering due to  "''DRM_IOCTL_MODE_CREATE_DUMB failed: Cannot allocate memory''' caused by insufficient Quality Assurance at mesa upstream tracked on https://gitlab.freedesktop.org/mesa/mesa/-/issues/8198.

The fix has been merged in https://gitlab.freedesktop.org/mesa/mesa/-/commit/c426e5677f36c3b0b8e8ea199ed4f2c7fad06d47 and is part of Linux 6.2 so as long as you build ""and use"" this kernel the display should work without an issue.

Note that if you boot and build on broken kernel then you can use serial console on BAUM 115200 to fix the issue.

As of 03/07/2023-EU NixOS 23.05 is shipped with LTS kernel which is 6.1 to get non-broken kernel you can use the following configuration:

<pre>
# configuration.nix
boot.kernelPackages = pkgs.linuxPackages_6_3;
</pre>

Please let me know if you encounter this issue outside of known broken linux release. -- KREYREN

== Resources ==

1. [https://www.olimex.com/Products/DIY-Laptop/ Official product page]

2. [https://linux-sunxi.org/A64 linux-sunxi wiki page]

3. [https://u-boot.readthedocs.io/en/latest/board/allwinner/sunxi.html U-Boot documentation for the SoC]

4. [https://www.armbian.com/olimex-teres-a64 Armbian product page for Teres]