I created U-boot from Padavan sources.
My hardware for test is:
GL.iNet GL-MT300N V2
128MB = 1024Mb
MTK MT7628NN @580Mhz SoC
When I uploading the original firmware, true HTML, is written.
openwrt-mt300n-v2-3.211-1227.bin 12MB
When I upload my version of OpenWRT it is not written.
openwrt-ramips-mt76x8-glinet_gl-mt300n-v2-squashfs-sysupgrade.bin 4.8MB
Build is OpenWRT v21.02.2
Targhet -> Ralink MIPS
Subtarghet-> MT76x8
Profile->GL.iNet GL-MT300N V2
No other change to config.