Hey all. I know with the last 2 firmware releases for the RM551E-GL AT+QADBKEY? was removed and replaced with something different/stronger.
So, here’s a version of RM551EGL00AAR01A04M8G_A0.001.A0.001 that has ADB pre-unlocked. The AT+QCFG="usbcfg" command will work fine on this version when you try to enable ADB.
I call it
RM551EGL00AAR01A04M8G_adb_2025_07_15
Enjoy 
Do you have anything like this for the RM520N-GL by any chance? AT+QADBKEY? just errors every time for me.
May be you have this firmware with SDXPINN preinstalled?
Should be able to downgrade firmware to an older version where qadbkey still exists and unlock it that way. ADB enabled/unlock status persists when you flash back to the newer firmware.
I’ll make a 520 firmware eventually
SDXPINN is the codename of the system running on the RM550/551 and equivalent LGA modules. The 520’s system codename is sdxlemur
Yes, I am asking about 551e-gl
Does it ever lock back up on it’s own or would I have to lock it again if I didn’t want it enabled any more?
It’ll stay enabled. QCFG usbcfg status remains the same unless you change it. Maybe an erase all flash might reset that but I’m not sure. You’d definitely need to do a xqcn restore if you did an erase all flash though. It’s also possible that the QCFG “resetfactory” command would also reset that.
Okay deadly, that’s great to hear. Thanks for the info, it’s been extremely helpful.
Any different between this and the newly R02 firmware?
Does anyone encounter memory leak on older firmware? It eventually hang RM551.
I plan to update the fw, not sure to go with latest R01 or hacked R02.
R01A04 is the last firmware I made a custom version from. I have seen where now and then a reboot is helpful but seemed to be improved from R01A02 (we skipped R01A03 way to many problems)
R02A01 so far seems promising but I honestly haven’t had a chance to really fully test it. I was able to make a preliminary custom version of it last night/this morning. They’ve upgraded the OpenWRT version from 22 to 23 so that alone is a big change. They’ve also switched to an A/B partition layout and resized a bunch of stuff. Hell it even looks like ‘rawdata’ had a _b now too. Since it’s such a big partition layout change they ended up changing the project name (they added an extra A is all) in the firmware XML so this requires an erase all flash procedure. In order to preserve the modules calibration data properly and to be able to actually use the radio in CFUN 1 to connect you have to backup the xqcn data and restore it after the erase all flash. I’ll have a YouTube video going over the process in windows after I finish the custom firmware and update my QuecDeploy a little 
Heck yeah! Go cameron!
@iamromulan Thank you for the awesome work, and I have watched your YouTube video.
Can you give us an update after testing the version? What are the cons and pros? I’m very excited to hear any good changes on this version, as 04 it’s not that bad, but not the best.
Keep up the good work, all the best.