: The bootloader for the A133 requires specific initialization for DRAM and serial UART. Some developers use custom versions like u-boot-2022.10-Allwinner-A133 for experimentation.
For projects requiring a stripped-down Linux environment, is an excellent choice. Community developers have published configurations for the A133, allowing you to generate a flashable img to write to an SD card. This method gives you a high degree of control and minimizes proprietary blobs. allwinner a133 firmware work