Ultramarine for TrimUI Smart Pro S

Ultramarine Linux for the TrimUI Smart Pro S (TG5050 / Allwinner A523). The working mainline path uses pinned U-Boot and TG5050 kernel integration sources, a mkosi-built systemd initrd, and an ARM64 Fedora/Ultramarine root filesystem.

• BootROM loads mainline SPL from LBA 256.
• SPL loads the U-Boot FIT from LBA 512 and hands off through the A523 TF-A BL31.
• U-Boot reads extlinux from p1 and loads Image, the board DTB, and the mkosi-built systemd initrd.
• The initrd discovers, checks, and mounts p4 before switching to the real systemd installation.
• p1 is the 1 GiB /efi ESP, p2 is the 1 GiB /boot filesystem, and p3 is the direct root.

The vendor boot inputs remain available for reference/recovery, but the mainline path does not boot the vendor boot package or Android ramdisk.

The optional vendor GPU stack is built separately as a system extension:

just --justfile mkosi.profiles/tg5050/justfile bsp-sysext

build/ultramarine-tg5050-bsp-drivers.raw contains the matched vendor libmali EGL/GLES/GBM userspace, Vulkan ICD, CSF firmware, and the 5.15.147 mali_kbase module tree. It is intended for the matching vendor BSP kernel only. It cannot make mali_kbase work with the mainline kernel, and the mainline Panfrost and vendor Mali stacks remain mutually exclusive.

The GPU stacks are selected across a reboot rather than loaded side by side. For vendor Mali mode, copy the extension to /var/lib/extensions/, run systemd-sysext refresh, and reboot. To return to Panfrost, remove the vendor extension image, run systemd-sysext refresh, and reboot. The vendor extension's /usr/lib/modprobe.d/ policy blacklists Panfrost only while that extension is active; the base image does not blacklist mali_kbase.

Panfrost is now built directly by the custom vendor-kernel RPM as a matching kernel module; a separate Panfrost sysext is not required.

Board-owned vendor inputs and profile-local overlays live under mkosi.profiles/tg5050/:

boot-resource/             minimal vendor/update resources for p1
partitions/boot0.img       vendor boot0/SPL source
partitions/boot_package.fex vendor U-Boot/boot-package source
partitions/vendor-boot.img padded 96 MiB vendor p3 boot-image source
boot-artifacts/            extracted vendor kernel and DTB research artifacts

Requirements include mkosi, systemd-repart, sfdisk, mkenvimage, an AArch64 cross compiler, e2fsprogs, and standard loop-device support. Clone submodules first. The legacy Linux integration submodule remains pinned at the exact v7.2-rc3 commit (a13c140cc289) for provenance, while the active RPM build consumes the stable 7.2.0 archive from kernel.org. The matching TG5050 integration submodule remains pinned separately. The build creates and recreates a disposable kernel worktree under build/; it does not modify the pinned Linux checkout.

git submodule update --init --recursive
just --justfile mkosi.profiles/tg5050/justfile mainline-image

The mkosi configuration is composed in three layers: the board-agnostic base appliance profile (user session, services, repos), a shared board profile, and a boot stack overlay. Use --profile=base,tg5050,tg5050-mainline for the mainline kernel, systemd-boot ESP, and matching modules, or --profile=base,tg5050,tg5050-bsp for the vendor BSP module tree.

This applies the pinned TG5050 patchset, validates required built-in drivers, builds the kernel and modules, builds the three out-of-tree AIC8800 modules, stages the stock firmware in the driver's flat runtime layout, builds both the systemd and BusyBox rescue initrds, assembles the four-partition image, and verifies the generated filesystems and raw bootloader slots.

Inspect a completed image:

sha256sum build/ultramarine-trimui-mainline-6g.raw
sudo sfdisk -d build/ultramarine-trimui-mainline-6g.raw
sudo sfdisk --verify build/ultramarine-trimui-mainline-6g.raw

Use the 32 GiB target card, not the preserved known-working 8 GiB template. Confirm the target device carefully before writing:

lsblk -o NAME,PATH,SIZE,MODEL,TRAN,RM
sudo dd if=build/ultramarine-trimui-mainline-6g.raw \
  of=/dev/sdX \
  bs=16M status=progress conv=fsync
sync

For iterative development, update only the verified boot payloads or rootfs:

just --justfile mkosi.profiles/tg5050/justfile flash-mainline /dev/sdX
just --justfile mkosi.profiles/tg5050/justfile flash-rootfs /dev/sdX

The first recipe preserves GPT and p2-p4. The second rewrites only p4 and performs a complete source/target comparison after writing.

The compact image occupies roughly the first 6.8 GiB of a larger card. Its final p3 partition is the direct Ultramarine system root; there is no p4/p5 bootstrap or secondary root partition.

The default extlinux entry uses the mkosi-built systemd initrd. A second entry keeps the static BusyBox initramfs as a pre-switch-root rescue environment.

The pinned kernel integration includes the AIC8800 SDIO build recipe. The profile stages aic8800_bsp, aic8800_fdrv, and aic8800_btlpm against the exact kernel release, generates depmod metadata, and flattens the stock D80/DC firmware into /lib/firmware/aic8800_sdio/. On tested hardware the two SDIO functions enumerate as c8a1:0082 and c8a1:0182, bind to aicwf_sdio and aicbsp_sdio, and expose wlan0 to NetworkManager.

The verified input, rumble, fan, power-button, display, USB, serial, and battery details are documented in:

mkosi.profiles/tg5050/board/IO.md

The p4 rootfs enables an early ConfigFS RNDIS gadget on the bottom USB-C gadget port. It assigns the device 192.168.42.1/24; this is the preferred bring-up path for SSH and logs. The top USB-C port is host-only.

A serial getty is also enabled on ttyAS0, but physical UART access requires the debug header. good luck opening up the console

For local development, add ignored configs under mkosi.profiles/tg5050/mkosi.extra/etc/NetworkManager/system-connections/ and mkosi.profiles/tg5050/mkosi.extra/root/.ssh/.

The TrimUI Smart Pro S uses the vendor Mali G57 userspace from Knulli rather than Mesa/Panfrost. The Vulkan loader needs the board ICD manifest:

/usr/share/vulkan/icd.d/mali_icd.json

The vendor stack is otherwise provided by the TG5050 profile prepare hook and mkosi.extra: libmali.so, vendor GBM/EGL/GLES, mali_kbase.ko, and CSF firmware. Without the ICD manifest, vulkaninfo reports Found no drivers; with it, vkcube works.

The compositor tests were performed on the live device using a PAM/logind session bound to tty1 and the DRM backend:

Cage and Labwc were tested with the vendor GBM/EGL/GLES path. Cage can run a startup command such as swaybg, but its kiosk model is not suitable as the main shell if the device needs persistent OSDs. Sway is the current default direction; Labwc remains worth developing as a lighter configured-shell alternative.