Quickstart

This page gets your board running by the shortest path. Pick either of the two routes; both require you to be able to get the board into FEL download mode.

What you need

• A YuzukiNeko and a USB data cable (not a charge-only cable). The board has only one USB-C port, which both supplies power and serves as the FEL download port and the USB device/host port.
• A USB-to-serial adapter (3.3 V logic) to view the console output. The serial port defaults to 115200 8N1 with no flow control.
• A Windows / Linux / macOS host machine.
• The xfel or rfel download tool, see FEL download mode and tools.

Tip

All external interfaces are designed for 3.3 V logic; the 5V pin is power only, so do not connect a 5 V signal to a GPIO.

Identify your board revision

The silkscreen and the PCB carry the revision number. Pin labels and some components differ between revisions, so take a look before you start:

Revision	Points to note
V1.3	PD pin silkscreen is wrong (from PD10 onwards each label is 2 lower than the real GPIO), so convert using the errata table; the microSD detect pull-down is too large
V1.4	Silkscreen corrected; the microSD detect pull-down R11 is still 10 kΩ, change it to 1 kΩ
V1.5	Added a dedicated PSRAM LDO, enabling 32 MiB PSRAM; R11 is already 1 kΩ

See Errata and revision differences for details.

Route A: flash RustSBI + Asterinas and boot into a BusyBox shell

This suits you if you want to see an interactive system straight away. The image is already in the repository under 02_Firmware/RustSBI-Asterinas/.

1. Hold the FEL button, connect the USB cable, then release the button.
2. Check the FEL connection:

   xfel version
   xfel spinor

   It should identify the F101 (chip ID 0x00193700) and 16 MiB of Flash.
3. (Strongly recommended) back up the existing Flash first:

   xfel spinor read 0x0 0x1000000 neko-backup.bin

4. Write, then read back to verify:

   xfel spinor write 0x0 yuzukineko-rustsbi-asterinas.img
   xfel spinor read 0x0 0x6d0000 readback.img
   sha256sum yuzukineko-rustsbi-asterinas.img readback.img

   The image is 7,143,424 bytes, which is exactly 0x6d0000, so the read-back range is the same length as the image; the two digests should match, and should also match the record in SHA256SUMS. See the firmware page for details.
5. Release the FEL button and reset:

   xfel reset

6. Open a serial terminal at 115200 8N1 and you will be in a BusyBox shell.

For the full instructions, including how to replace each component individually, see RustSBI + Asterinas.

Tip

If you want your changes to persist (a writable root filesystem that survives a reboot), or you need an RV64I build, use the Linux image from the prebuilt images instead. The procedure is the same, but that image covers the whole 16 MiB, so writing it also overwrites the data persisted on the board.

Route B: develop with Zephyr

This suits users who need a full RTOS, drivers and multimedia features. Zephyr’s yuzukineko board support lives in the F101 workspace, see Zephyr.

Next steps

• Want to attach peripherals → Pinout
• Want drag-and-drop .uf2 flashing → UF2 drag-and-drop flashing
• Hitting problems → FAQ