Reprovisioning the OS without an eMMC reader#

No reader, and you don’t want to pull the module? You can put a fresh OS on the eMMC from the running board. The trick is the microSD slot: the H616 boots SD before eMMC, so you boot a fresh image from a card and clone it onto the eMMC from there.

There is no shortcut over USB — the board exposes no USB-C / OTG port, so the usual sunxi-fel + U-Boot ums route to reach the eMMC over USB is off the table (see why FEL is out). SD-boot-and-clone is the only no-reader path.

Boot from SD, clone to eMMC#

Sovobian on microSD  →  boot from SD  →  armbian-install  →  system now on eMMC

  1. Write the Sovobian image to a microSD (Etcher, Armbian Imager, or dd). Use Sovobian, not a plain BTT CB1 image — Sovobian has the 40 MHz eMMC overlay baked in. Booting a stock CB1 image and cloning it would install a 120/150 MHz eMMC device tree, which “may appear to boot and then fail unpredictably” (see the CB1 difference).

  2. Insert the card and power on. The board boots from the SD ahead of the eMMC. Do your first-boot setup — the friendly way is on the easy-install page.

  3. Clone the running SD system onto the eMMC:

    sudo armbian-install

    Pick the option that installs the system to the eMMC and boots from it (“Boot from eMMC — system on eMMC”; on older images this tool is nand-sata-install). It copies the currently-running SD system, including /boot, onto the eMMC.

  4. Power off, pull the SD, power on. The board now boots the freshly-installed system from the eMMC.

The friendly TUI does the same thing, if you’d rather click through a menu: armbian-config → System → install to eMMC.

Needs-verification on the Zero specifically. The SD-boot + armbian-install route is confirmed on the SV08 (same H616 host, same CB1 lineage, same boot ROM) and endorsed by Sovobian’s own docs, but a Zero-specific transcript wasn’t found — treat the exact menu wording and the clone as reproduced-elsewhere, not Zero-verified. Two things to check after cloning: that the eMMC runs at the verified 37.5 MHz clock (i.e. the overlay-user/ overlay travelled to the eMMC), and that the board still comes up on the eMMC alone. Keep the SD card — with no OTG, it is your only rescue path if the eMMC install goes wrong.

Or just stay on the SD#

Nothing forces the system onto the eMMC. Many people run the Zero entirely from a microSD and leave the stock eMMC module unscrewed on a shelf as a factory backup. Use a good card — intermittent SD-boot failures get reported, and a flaky card is the usual cause.

Then what#

Once the OS is where you want it, continue with the application stack; if the MCUs are still on vendor firmware, do the firmware migration too.