RZ-G/RZ-G2L Flash Programming

RZ/G2L cannot boot from USB, so at the end-of-line there are two/three real viable options:

1. Boot from SCIF
2. Use JTAG
3. It is worth to mention that, in general, if a QSPI FLASH is present on the custom board, it can also be bought preprogrammed

In any of the cases above the goal is to have U-Boot up and running, then there are plenty of options to program the rootfs: ethernet, USB as host, USB with Mass Storage gadget, etc.

With option 1, you can download the flash writer and program the bootloaders (ATF and U-Boot) into QSPI / eMMC boot partition, then reset and run U-Boot.

With option 2, you can download ATF and U-Boot via JTAG and then run the boot loaders without having to initially program them. Once U-Boot runs, you can program both bootloaders and rootfs.

With option 3, QSPI has already bootloaders pre-programmed, so U-Boot is already available.

All the options above may not require any human intervention and can be to a certain extent automatized.