Adding OpenWrt support for MikroTik cAP ac

So you have OpenWrt running already?
If so, then please make a full flash dump first.

Netinstall see other routerboard, that is not a problem.

I have problem with flashing OpenWRT on Mikrotik cAP ac:

I did the following on RouterOS:

/ system routerboard settings set boot-device=try-ethernet-once-then-nand
/ system routerboard settings set boot-protocol=dhcp
/ system routerboard settings set force-backup-booter=yes

Then, I compiled the image:

$ git clone -b hAP-ac2-cleanup
$ cd ~/openwrt && ./scripts/feeds update -a
$ cd ~/openwrt && ./scripts/feeds install -a
$ make menuconfig
$ time make -j 4 V=s

After compiling, I got the following:

$ ls -al bin/targets/ipq40xx/mikrotik/
total 11808
drwxr-xr-x 3 kmarzic 64000     313 Dec  6 10:52 .
drwxr-xr-x 3 kmarzic 64000      22 Dec  6 10:45 ..
-rw-r--r-- 1 kmarzic 64000     268 Dec  6 10:56 config.buildinfo
-rw-r--r-- 1 kmarzic 64000     337 Dec  6 10:56 feeds.buildinfo
-rwxr-xr-x 1 kmarzic 64000 5888564 Dec  6 10:58 openwrt-ipq40xx-mikrotik-mikrotik_hap-ac2-initramfs-kernel.bin
-rw-r--r-- 1 kmarzic 64000    2666 Dec  6 10:58 openwrt-ipq40xx-mikrotik-mikrotik_hap-ac2.manifest
-rw-r--r-- 1 kmarzic 64000 6226729 Dec  6 10:58 openwrt-ipq40xx-mikrotik-mikrotik_hap-ac2-squashfs-sysupgrade.bin
drwxr-xr-x 2 kmarzic 64000    8192 Dec  6 10:56 packages
-rw-r--r-- 1 kmarzic 64000     627 Dec  6 10:58 sha256sums
-rw-r--r-- 1 kmarzic 64000      18 Dec  6 10:56 version.buildinfo

On Windows, I did the following:

  • set IP address to
  • connected port1 on cAP ac with Windows PC.
  • used pxesrv.exe to flash openwrt-ipq40xx-mikrotik-mikrotik_hap-ac2-initramfs-kernel.bin
  • pxserv.exe is showing that image is requsted by cAP ac.

After that, one LED diode on device is blinking red.
I can not ping cAP ac on port2 using

It seems that I am doing something wrong.
If you know how to do it, please, share...

Guys, hAP ac2 is not drop-in compatible with cAP ac.
I don't have a cAP ac to test so don't just blindly flash.

Can You upload full instruction - how to do right install OpenWRT on MikroTik cAP ac?
As I understand :

  1. Backup your license with WinBox
  2. Go to “System”-“Routerboard”-"Settings": Boot device - Select “Try ethernet-once-then-nand” and select “Force Backup Booter”.
  3. Setup PXE server and select "openwrt-ipq40xx-generic-mikrotik_hap-ac2-initramfs-fit-uImage.elf"
  4. Reboot MikroTik and let it boot OpenWRT
  5. Select "openwrt-ipq40xx-generic-mikrotik_hap-ac2-squashfs-sysupgrade.bin" file within OpenWRT web GUI and flash it.

For flashing OpenWRT I need enable serial console in RouterOS?
For what I need MTD files?

There is no instruction -- cAP ac is not supported, yet.

@ank - I have two cAP AC units that I have successfully flashed with yhudit's build from the hAP AC2 thread: Support for Mikrotik Hap AC2

Make sure to also install irqbalance as it improves download throughput from around 350mbps to 450+ mbps - see details in Blaze's post: Support for Mikrotik Hap AC2

Your steps are correct, not sure about any MTD files nor having to enable serial console, I didn't need anything like that.
Let me know if you need additional help getting the build to work on your cAP AC.

Also for anyone seeing this thread that might be asking themselves why someone would put an experimental version of OpenWRT instead of RouterOS, the answer in my case is pretty simple: support for 802.11r - it works extremely well with Apple iOS and makes roaming between APs seamless, as opposed to the disaster that is RouterOS in this regard.

I actually get better overall performance with this firmware on cAP AC than I get with the "official" OpenWRT for the wAP AC I have outside.

I try download bin file via Windows "Tiny PXE Server" (rfc951=1 in sec. dhcp - added)
If I select on MT: Вoot Protocol- bootp, I can't upload bin file:

15:56:45 DHCPc:discovering for another DHCPd on LAN
15:56:45 ROOT=C:\1
15:56:45 DHCPd started...
15:56:45 TFPTd started...
15:56:45 HTTPd:80 started...
15:56:50 DHCPc:no other DHCPd discovered
15:57:21 DHCPd:REQUEST received, MAC:74-4D-28-A4-84-D9, XID:1017C5AC
15:57:21 DHCPd:ACK sent, IP:, XID:1017C5AC
15:57:21 TFTPd:DoReadFile:openwrt-ipq40xx-mikrotik-mikrotik_hap-ac2-initramfs-kernel.bin B:1452 T:0
15:58:06 DHCPd:DISCOVER received, MAC:74-4D-28-A4-84-D9, XID:35F4004B
15:58:07 DHCPd:OFFER sent, IP:, XID:35F4004B
15:58:07 DHCPd:REQUEST received, MAC:74-4D-28-A4-84-D9, XID:35F4004B
15:58:07 DHCPd:ACK sent, IP:, XID:35F4004B

LED diode on device is blinking red. (as on kmarzic)
after reboot device - loading RouterOS

if I select "dhcp" - nothing loaded :slight_smile:

16:11:34 DHCPd:DISCOVER received, MAC:74-4D-28-A4-84-D9, XID:C2EC20B2
16:11:34 DHCPd:OFFER sent, IP:, XID:C2EC20B2
16:11:34 DHCPd:REQUEST received, MAC:74-4D-28-A4-84-D9, XID:C2EC20B2
16:11:34 DHCPd:ACK sent, IP:, XID:C2EC20B2
16:13:41 DHCPd:DISCOVER received, MAC:74-4D-28-A4-84-D9, XID:B077C9F5
16:13:41 DHCPd:OFFER sent, IP:, XID:B077C9F5
16:13:41 DHCPd:DISCOVER received, MAC:74-4D-28-A4-84-D9, XID:373AB9A6

TFTPD64 server - can't look PXE request from MikroTik and can't put bin file as "TFTP client".

What program did you use to load the bin file into MikroTik?

When the LED is blinking RED you have to connect your PC to port nr 2 (LAN) instead of 1 (WAN).
You can bridge these two ports afterwards so you don't have to hook-up two cables to the device.
This is when you have to flash the sysupgrade file so that your device keeps OpenWRT after reboot.

BTW, I put some black duct tape on all LEDs and for me it works great with the square cover.

Sorry, RED Led not's ON constantly after message:
DoReadFile:openwrt-ipq40xx-mikrotik-mikrotik_hap-ac2-initramfs-kernel.bin B:1452 T:0

and after switching fron WAN to LAN port - nothing action ...

Yes it's OK that the Red LED is blinking all the time. I suppose you are using a different cable to connect to port 2 (the one used to reach the luci interface via, because if you take the cable out of port 1 it will reboot and you will go back to RouterOS.

Yes, of course :slight_smile:
Red LED is not blinking! It's ON constantly after ~20-30 sec. from start downloading TFTPd:DoReadFile:openwrt-ipq40xx-mikrotik-mikrotik_hap-ac2-initramfs-kernel.bin

I understand ... after that I can connect from Lan2 to OpenWrt ( and download second image...

It works (but only RED Led is always ON - use black duct tape :smile: ).
Thank you very much!
And my case is the same: support for 802.11r

Which build do you currently use for cAP ac?

Hello everybody and happy new year ! i currently use rb750gr3 with openWRT you use ac2 mikrotik but the new hap ac3 is also flashable you thinked ,

Mikrotik is my favorite model easy to flash debrick etc :slightly_smiling_face:

i see he has architecture arm32 so he support wan gigabit with qos ??

confirm that it works. Moreover, it works also for the new wAP AC (RBwAPG-5HacD2HnD). [IPQ-4018 CPU] it is in 1:1 correspondence with the cAP AC model (except that you can also power it via DC jack and it has an IP54 protection)

as far as I can see the new wAP AC is also not listened in Not sure whether a separate entry is needed, since the procedure and builds can be taken from cAP AC

I tried a few of the builds mentioned in this topic and I found the WiFi connectivity unreliable, especially for 5 ghz, where I get disconnects as soon as a bandwidth brust takes place (for instance, when testing download speeds).

The LEDs are not working properly as well - the power and red leds stay solid on (but we can make them blink using custom led configs), the other ones won't work.

Any ideas are welcome and many thanks to the contributors of this effort -- cAP AC will most likely not work with MT's new wave2 drivers and it's users will only have OpenWRT as an option for proper 802.11r (among others) support.

In terms of makefiles producing images, probably no. Are even LEDs the same? Does the board description need editing so right information is shown under System luci tab?

In terms of tables and wiki pages, yes. It needs entries in order to be discoverable as supported and so users know which images to use and so people have a pointer to known working flash instructions. (ie. common tftp instructions).

My initial cAP ac PR

  • cAP ac based dts file
  • cAP ac based BFS
  • LEDs are in better shape
  • VLANs ... as good as you can get with ipq40xx

ok, opened a new thread on the new wAP AC

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