RetroCompass
RetroCompass

Smart Pro — Custom firmware

Quick answer

Button combo

VOL-+POWER(recovery flash, if needed)

Steps

  1. 1Pick a Smart Pro-supported OS: CrossMix-OS, MinUI, NextUI, or Knulli.
  2. 2Format a microSD (TF) card as FAT32 (CrossMix-OS expects the label CrossMix).
  3. 3For CrossMix-OS/MinUI/NextUI extract the release to the card root; for Knulli write the .img with Balena Etcher or Raspberry Pi Imager.
  4. 4Add BIOS and ROMs to the matching folders, then insert the card and power on.
  5. 5If a card needs a base reflash, put trimui_tg5040.awimg at the root and boot holding VOL-.
Last verified: 2026-06-20Source: github.com

The Smart Pro (TG5040) boots custom OSes straight from microSD, so the stock NAND stays intact. CrossMix-OS is the flagship Smart Pro project (TrimUI stock UI with extra emulators, apps, themes and PortMaster); MinUI and its fork NextUI offer a minimal launcher; Knulli officially supports the Smart Pro as a full EmulationStation/Batocera-style distro. The first boot can take longer while components like PortMaster install. RetroArch is bundled with most of these.

FAQ

Which custom firmware is best known for the Smart Pro?
CrossMix-OS was built around the TrimUI Smart Pro. MinUI, NextUI and Knulli also officially run on it; all boot from the microSD card.
Do I have to flash anything to internal storage?
No. CrossMix-OS, MinUI, NextUI and Knulli run from the microSD. Only flash trimui_tg5040.awimg with VOL- + POWER if a card needs a base/recovery reflash.

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