yes... wiki portion below;
WIP: Sat Dec 8 12:55:16 2018 version of gl-ar750s-squashfs-sysupgrade.bin results in the message
The uploaded image file does not contain a supported format. Make sure that you choose the generic image format for your platform.
See further https://forum.gl-inet.com/t/installing-openwrt-on-gl-750s/5291/4
It is NAND firmware for AR750S by default. If you build from OpenWRT official repo, it might be NOR firmware, so you should upgrade it on u-boot web. Please refer to this tutorial https://docs.gl-inet.com/en/3/troubleshooting/debrick/.
If you want to build a nand firmware, you have to use our repo. https://github.com/gl-inet/openwrt 3
Note: As of OpenWrt 19.07.4, gl-ar750s-squashfs-sysupgrade.bin still gives an unsupported format error on the web UI and sysupgrade command, but works fine through the router's debricking interface: power down, ensure only 1 network cable is plugged in, hold the reset button, power on, wait until the led blinks 5 times and stays on, then release reset button. Change your IP to 192.168.1.2 and connect to http://192.168.1.1, where you can upload and flash the sysupgrade.bin image.
OEM installation using the TFTP method
Certain version produced in 2018 and prior have a bug in the U-Boot implementation that requires Windows for use with U-Boot.
The router works properly once booted; the restriction is only for use of U-Boot over Ethernet.
Only after updating U-Boot can U-Boot be used with macOS, Linux, FreeBSD, or the like.
See the GL-iNet forums for further details and upgrade procedure on a Windows machine.
Upgrade takes just a few minutes, but requires a Windows machine,
Specific values needed for tftp
it is quite unusual for wiki notes ( at least primary install notes for openwrt ) to point to third party repos... and they discuss uboot version updates / complexities here too...