Linux/AM3352: Where to fix the MAC address for the HOST and the SELF/LOCAL in the BBB ?

Moses Christopher Bollavarapu

Intellectual 980 points

Part Number: AM3352

Tool/software: Linux

Hi,

I am trying to fix the MAC address of USB (local and host).

I found that u_ether.c is allocating a random MAC for both self and host, upon every boot.

So, I'd like to fix that to a particular HOST MAC address and SELF/LOCAL MAC address.

Something like, MAC- A1:22:33:44:55:B1 ; HOST_MAC: C1:33:22:44:55:A4

But, I couldn't get proper information on that.

Could you kindly provide some hints on that ?

P.S: I am using USB-RNDIS, not the physical Ethernet port.

over 6 years ago

0 Moses Christopher Bollavarapu over 6 years ago

Intellectual 980 points

dmesg shows something like this...

[ 16.600794] using random self ethernet address
[ 16.600811] using random host ethernet address
[ 17.241100] nf_conntrack version 0.5.0 (4096 buckets, 16384 max)
[ 17.346762] usb0: HOST MAC 06:90:c9:f7:9d:b2
[ 17.349364] usb0: MAC c2:24:d8:3b:cc:6a

The above mentioned MAC address' are changing upon every boot.

0 Bin Liu over 6 years ago in reply to Moses Christopher Bollavarapu

TI__Guru**** 168141 points

Hi Moses,

You can use module parameters to specify those MAC addresses.

root@am335x-evm:~# modinfo g_ether
...
parm:           idVendor:USB Vendor ID (ushort)
parm:           idProduct:USB Product ID (ushort)
parm:           bcdDevice:USB Device version (BCD) (ushort)
parm:           iSerialNumber:SerialNumber string (charp)
parm:           iManufacturer:USB Manufacturer string (charp)
parm:           iProduct:USB Product string (charp)
parm:           qmult:queue length multiplier at high/super speed (uint)
parm:           dev_addr:Device Ethernet Address (charp)
parm:           host_addr:Host Ethernet Address (charp)
parm:           use_eem:use CDC EEM mode (bool)

0 Moses Christopher Bollavarapu over 6 years ago in reply to Bin Liu

Intellectual 980 points

Yes, It works with g_ether, But I don't want to load g_ether.
I am trying to use u_ether and usb_gadget

0 Bin Liu over 6 years ago in reply to Moses Christopher Bollavarapu

TI__Guru**** 168141 points

What do you mean by "usb_gadget"?
Please explain the detail or exact procedure of how you use u_ether and usb_gadget?

0 Moses Christopher Bollavarapu over 6 years ago in reply to Bin Liu

Intellectual 980 points

I found the solution.
We can try to write the host_addr and dev_addr to the files under /sys/kernel/configs/usb-gadget/gadget-name/functions/***/host_addr and dev_addr

0 Moses Christopher Bollavarapu over 6 years ago in reply to Moses Christopher Bollavarapu

Intellectual 980 points

Something like this,
github.com/.../gadget.sh

Thanks for the prompt reply Bin :-)

0 Bin Liu over 6 years ago in reply to Moses Christopher Bollavarapu

TI__Guru**** 168141 points

Okay, you use usb gadget configfs, yes, you can define those information in the configfs entries.

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Linux/AM3352: Where to fix the MAC address for the HOST and the SELF/LOCAL in the BBB ?