Meraki MR18

This forum discuss about how to JTAG different devices.
esc
Posts: 5
Joined: Thu Apr 09, 2020 10:13 pm

Re: Meraki MR18

Post by esc » Wed Apr 15, 2020 8:13 am

So I downloaded a full backup from a friend and uploaded to my device. The device is working. Hooray :)

Apart from the MAC address of the network card, what else can be a problem with this copy? Can't edit it somehow?

For now, I used the mac address change script on this page
http://jhshi.me/2015/01/19/fix-mac-addr ... pcinnLgqM8

Thank you very much for your help.

usbbdm
Posts: 8648
Joined: Mon Jul 18, 2005 9:33 pm

Re: Meraki MR18

Post by usbbdm » Wed Apr 15, 2020 8:17 am

As long as you are behind a NAT, you are OK. Play with openwrt and have fun with it.

rjboonstra
Posts: 10
Joined: Sun Mar 15, 2020 10:28 am

Re: Meraki MR18

Post by rjboonstra » Fri Sep 18, 2020 7:48 pm

I have an interesting question. I purchased an old MR18 on eBay and can flash it. When I reboot the unit, though, I get a slightly different response when watching the serial console... and then it stops. Watching Ricardo Cooper's video "Flashing the Meraki MR18 with USBJTAG NT" and then stopping at 9:37/25:14, you can see his serial console. The text below is a comparison where the red is where it starts to deviate:
[ 16.493670] ieee80211 phy1: Atheros AR9300 Rev:4 mem=0xb0000000, irq=40
[ 16.500467] PCI: Enabling device 0000:01:00.0 (0000 -> 0002)
[ 16.506560] ath9k 0000:01:00.0: Direct firmware load for pci_wmac1.eeprom failed with error -2
[ 16.515338] ath9k 0000:01:00.0: Falling back to user helper
[ 18.816773] ieee80211 phy2: Atheros AR9300 Rev:4 mem=0xb2000000, irq=41
[ 25.207543] device eth0 entered promiscuous mode
[ 25.230400] IPv6: ADDRCONF(NETDEV_UP): br-lan: link is not ready
[ 25.661611] eth0: link up (1000Mbps/Full duplex)
[ 25.666337] br-lan: port 1(eth0) entered forwarding state
[ 25.671867] br-lan: port 1(eth0) entered forwarding state
[ 25.709759] IPv6: ADDRCONF(NETDEV_CHANGE): br-lan: link becomes ready
[ 27.669730] br-lan: port 1(eth0) entered forwarding state

At this point, the OpenWRT does not start nor does the router obtain an IP address. I flashed the device twice, both with the same response. Has anyone seen this before?

Also, here is the output from USBJTAGNT:
Found Address= 00000000 ~~~~~~~~~~~
-getram kernel2
Time 00:00:48 (.803)
-DETECT
IDCODE 00000001
Atheros
IMPCODE A0414000
EJTAG V2.6
DMA not supported
Found Address= 00000000 ~~~~~~~~~~
-erase kernel1
Erase starts...
Erase time 00:00:00 (.230)
-erase kernel2
Erase starts...
Erase time 00:00:00 (.232)
-getram kernel2
Time 00:00:48 (.785)
-erase kernel1
Erase starts...
Erase time 00:00:00 (.225)
-getram kernel1
Time 00:00:48 (.784)
-ldram kernel2
~~~/Documents/USBJTAG/MR18/openwrt-ar71xx-nand-mr18-initramfs-kernel-ecc.bin loaded
-program kernel2
Erase starts...
Erase time 00:00:34 (.080)
Program speed 4159.02 KB/s
Program time 00:00:02 (.080)
Program pass, if no further programming needed, power off/on the target
-cmpram kernel2
Time 00:00:48 (.784)
Compare data OK

Note that there are a few extra erases in the above and I did a verify. Thanks!

rjboonstra
Posts: 10
Joined: Sun Mar 15, 2020 10:28 am

Re: Meraki MR18

Post by rjboonstra » Fri Sep 18, 2020 9:04 pm

Just updated the firmware in a second MR18 and got the exact same response. Not surprising, the boot.bin file for both units is exactly the same size, 528kB. Both original kernel.bin files were 8448kB. Not sure what might be the issue? Thoughts?

usbbdm
Posts: 8648
Joined: Mon Jul 18, 2005 9:33 pm

Re: Meraki MR18

Post by usbbdm » Fri Sep 18, 2020 9:45 pm

I can help you via zoom remote desktop to see what is goring wrong. Bottom line I can give you my backup and it should fix your issue.

rjboonstra
Posts: 10
Joined: Sun Mar 15, 2020 10:28 am

Re: Meraki MR18

Post by rjboonstra » Fri Sep 18, 2020 10:10 pm

Mistake on my end. I did not connect directly to the MR18 an Ethernet cable, but rather tried to do this via a switch. When I hard coded my IP address in my laptop, then I was able to reach it. Thanks.

rjboonstra
Posts: 10
Joined: Sun Mar 15, 2020 10:28 am

Re: Meraki MR18

Post by rjboonstra » Sat Sep 19, 2020 9:38 am

Actually, I might need to explore a different boot file. I just accidentally set my AP to DHCP and not cannot access it via the web interface even though it works as a wireless AP; I can see it on the network, but it also does not respond to pings nor SSH. Oops! It would be nice to have a access to the device via serial interface for the next time I make a mistake like this...

usbbdm
Posts: 8648
Joined: Mon Jul 18, 2005 9:33 pm

Re: Meraki MR18

Post by usbbdm » Sat Sep 19, 2020 11:54 am

DHCP does not matter much.
You should still be able to find the IP address of the router. Either go to your main router and find the IP address or use some sort of sniffer to find the IP of MR18.
Once you have the IP address you should be able to go to the web or SSH. Serial access is not absolutely needed in my opinopn.

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