Thank you for answer
Flashing
tftp 0x86000000 openwrt-18.06.1-ar71xx-generic-archer-c7-v5-squashfs-sysupgrade.bin
erase 0x9f0c0000 +4000b1
cp.b 0x86000000 0x9f0c0000 4000b1
After that:
bootm 0x9f0c0000
And system boots fine, everything works.
BUT!
After reset:
[NM_Error](nm_api_checkInteger) 00384: extra-para:49 52
[NM_Error](nm_api_checkInteger) 00389: factory boot check integer flag is not 1.
And halting
P.S. The same situation with development snap shot