difference between A20-OLinuXino-LIME2-s16M and A20-OLinuXino-LIME2?

[oeren]

What is the 16MB SPI flash memory for? Is it correct that you can install a bootloader on the 16MB SPI flash memory?
If you decide to leave the 16MB SPI flash memory empty, will the A20-OLinuXino-LIME2-s16M then work the same way as the A20-OLinuXino-LIME2? Thank you.

[sasha2002]

you can install a bootloader on the 16MB SPI flash memory

Yes
If you leave it empty it will not boot, in my case it's like this.
You can disable it and tell Lime2 to boot from user area
mmc bootpart enable 7 0 /dev/mmcblk1

[LubOlimex]

The board will boot without problems without SPI flash! In the case of A20-OLinuXino-LIME2-s16M and A20-OLinuXino-LIME2 - leaving the SPI empty won't cause issues.

The SPI flash is mainly needed when you have eMMC, to facilitate the boot process from eMMC (because the A20 bootloader doesn't support newer eMMCs). Hence we have no eMMC variants without SPI flash. But in the case of A20-OLinuXino-LIME2-s16M there is no eMMC so it is fine!