Disable BootROM or change the way to enter BootROM

[ihtgjhg]

Hello.

We’re using Mikrotiks with console port to remotely access switch’s console port over cellular network.

But because Mikrotik sends few lines of log during boot, Extreme switch sees this text (most likely SPACE characters in it) and enters the BootROM, and we have to boot it manually by sening “boot” command in BootROM.

We contacted Mikrotik about the possibility of disabling any output to serial port, and they said it wasn’t possible.

So, the questions are:

1. Is there a way to disable BootROM in Extreme?
2. Is there a way to change the way one enters BootROM from hitting <spacebar> to another key sequence, which is not likely to occur in logging text, e.g. Ctrl+B. Huawei user Ctrl+E, Cisco uses BREAK signal, and we’re fine with them in our setup.
3. If anybody ever faced such problem, how did you resolve it?

Best regards

[FredrikB]

Do you experience this when you have had a total power failure and the Extreme switch and the MikroTik are both booting at the same time? If so, you could possibly delay the start of the MikroTik using some delay timer. If the MikroTik is powered via an external 12 V DC power supply, you could do this quite easily with a time delay relay. Using industrial components like this one below, I imagine the cost would be something like 50 USD for the relay alone.

https://amperite.com/wp-content/uploads/2018/04/b.pdf

It can be done reliably with a simple NE555 timer circuit and optionally a relay for, say 10 USD.

/Fredrik

[Necheporenko__N · Accepted solution]

Hello ihtgjhg,

The issue is really unpleasant, but there is no way to fix it. BootROM is like a “BIOS” for EXOS with a very basic functionality. So if you “try to disable” or corrupt BootROM EXOS will not boot up. Also there is no way to remap keys for entering BootROM as it’s  code is small/basic/verified/compiled/loaded and stored in.

Actually, you are the first person faced such issue per my knowledge.

Best Regards,

Nikolay