3.10.49) with a patch was working (link below), and only squashfs filesystem.
|CPU||QCA9531-BL3A-R||500 Mhz||This SoC is currently not supported by OpenWrt|
|Flash||Winbond W25Q128FV||16 MB||SPI-NOR, 4K+0 bytes/sector, 32/64K/eraseblock|
500MHz is in contradiction to the OEM website (see above), which mentions 850MHz. Since this is higher than the QCA9531 can get, the SoC must also be questioned. — tmomas 2016/04/04 21:40
| || || || ||
A precompiled ramdisk image is available. Instructions about setting up a TFTP server can be found here. Press the RES button before powering it up, and keep pressing until the LED is blinking then up and down.
Please note that the aforementioned mechanism is not properly working on some boards. Don't worry, bott up the mikrotik board, connect your DHCP client to port 1. And address from 192.168.88.0/24 must be obtained. You can now telnet to the board, and configure it for TFTPboot.
Telnet user is
admin, leave the password empty.
telnet 192.168.88.1 system routerboard settings set boot-device=try-ethernet-once-then-nand system routerboard settings set boot-protocol=dhcp
Now reboot the board, it should boot from port0 now.