MA-E3xx シリーズと同様、ファームウェアのファイルは ZIP 形式となっています。
sftp などでファームウェアを実機に転送し、root 権限で “firmup” コマンドを実行してファームウェア更新を行います。

root@gemini:~# firmup /tmp/mas1xx_focal_v5_0_0rc5.img
### MA-S1xx series firmware update utility (for 2-area firmware).
* checking firmware file integrity... OK.
* custom firmup-pre script found.
* AT91Bootstrap file found.
  writing "at91bootstrap.bin" image to /dev/mtd0 ... succeeded.
Updating Area: 0 ...
* image file for kernel found, writing... succeeded.
* image file for kmod found, writing... succeeded.
* image file for initramfs found, writing... succeeded.
* image file for rootfs found, writing... succeeded.
* DTB file(s) found.
  writing at91-centurysys-gemini-00.dtb... succeeded.
  writing at91-centurysys-gemini-01.dtb... succeeded.
  writing at91-centurysys-gemini-01.dtbo... succeeded.
  writing at91-centurysys-gemini-02.dtbo... succeeded.
  writing at91-centurysys-gemini.dtb... succeeded.
* Bootloader file found.
  writing "barebox.bin" image to /dev/mtd2 ... succeeded.
  erasing bootloader environments (/dev/mtd1)... done.
* updating default firmware area: 0
Succeeded.