Hello,

I'm working on an setup were carambola is connected to two different networks wich have to be seperated.

Good thing is: it works perfectly with 2 VLAN's, both networks are completly seperated.

Bad thing is: On startup or reboot before the system has booted and has configured the rt305x-switch part of carabola it just does what an unconfigured switch would/should do: it connects the two networks.

My Problem is: that's not allowed to happen

Is there a way to change the default startup-behavior of the switch so that at least one port ist blocked while the system boots? Some kind like another 'firmware' (i don't mean OpenWRT) for the switch part of the board?

Regards,
Martin

First thing that is loaded on startup is the bootloader, so if you really need it right after startup that's the place to put your adjustements.

See datasheet (*) page 111 for the switch hardware setup stuff.

Simplified:
Edit bootloader source code, add code that configures switch right after system is poweder up, compile and flash bootloader

Next steps:
Buy JTAG to recover your board which is now possibly bricked 'cause you made any failure while adjusting bootloader code which causes the bootloader to fail booting

What I want to say:
It's possible, for sure.
But watch the hell out unless you're not 100% sure what you're doin'

*: http://www.tracermcc.ru/foto/bender/RT3 ... 8_0902.pdf

I do! Hopefully...

I was hoping for something without writing a patch for U-Boot. But thanks for your advice, I'll see what i can do!

Hello again,

for your interest: I found a solution.

Luckily there is a command patched into uboot that is able to access the switch. So there is no need to write a patch for uboot and to install a new version of the bootloader. The magic line is:

mdio.w 0 0 3900

Explanation:
mdio.w means write, mdio.r means read. On page no 127 of the datasheet you'll find the MII Control register. As the text on top of this page says you have to use PCR 0, that's the first zero. Then access register d00 (the first table, the second zero) and set bit 11. This disables port 0.

mdio.w 1 0 3900 will disable the other port.

Sounds very interesting.
Could you explain where and how the command would have to be issued ?

And i don't know which version of the ELDK was used to compile U-Boot. There are issues with using always the newest version.

This is way above my knowledge [though I do own a JTAG adaptor].

Maybe the dev guys from 8devices can help ?

Got a solution, and bricked it due to a tftp-error.

Did anyone ever JTAGged carambola and knows wich software is needed to do so?