FAQ
Download and boot
Section titled “Download and boot”xfel version does not find the device.
It did not enter FEL. Hold the FEL button while powering on, try another cable that carries data, and on Windows make sure WinUSB is installed with Zadig (VID 1f3a / PID efe8). See FEL.
It reports unsupported chip.
The xfel / rfel version is too old and does not support the F101. Upgrade and try again.
The board used to enter FEL, but no longer does. There is already a valid bootloader in Flash, so the board runs it directly on power-up instead of entering FEL on its own. You must hold the FEL button while powering on.
The board does not respond after writing Flash.
Read back the region you wrote and compare the SHA-256; make sure you wrote the full image rather than a single component (writing the three .bin files on their own does not install the devicetree and root filesystem). See RustSBI + Asterinas.
I want to restore the original firmware.
Use the whole-chip image you backed up earlier: xfel spinor write 0x0 neko-backup.bin, then read back to verify and reset. Without a backup there is no way to restore, so back up before touching Flash.
Hardware
Section titled “Hardware”On a V1.3 board PD12–PD20 do not work.
The V1.3 silkscreen is 2 lower than the real GPIO. Silkscreen PD12 is actually PD14. See errata.
The microSD card is not detected when inserted.
On V1.4 and earlier R11 (the PF6 pull-down) is 10 kΩ, which is too high. Change it to 1 kΩ, or set PF6’s output drive strength to its lowest setting in software.
Can I connect 5 V peripherals?
The GPIO is 3.3 V logic; the 5V pin is power only.
How do I wire up CAN? The SoC provides logic-level signals only; you need an external CAN transceiver and termination resistors.
Serial port and console
Section titled “Serial port and console”There is no output on the serial port.
Which pin group the console is on depends on the software you are running (Zephyr yuzukineko: UART1 PB0/PB1). Check the wiring, the 115200 8N1 baud rate and the common ground, and make sure TX/RX are crossed over.
Pasting long commands into RustSBI + Asterinas produces garbage. This image’s serial input is sensitive to long strings; set the terminal’s transmit delay to about 20 ms per character.
Software
Section titled “Software”Why can’t USB device/host functions and downloading be used at the same time? The board has only one USB-C port, which is also the FEL download port. Download first, then switch to the peripheral.