Debugging USB gadgets and USB interface

I'm using the host side USB interface and USB gadgets on my Mini2440. I'm
having problems with them and would like to debug them. 

In the kernel I've enabled the following to debug the USB gadgets:

CONFIG_USB_GADGET_DEBUG=y
CONFIG_USB_GADGET_DEBUG_FILES=y
CONFIG_USB_GADGET_DEBUG_FS=y

and to debug the host interface I've enabled:

CONFIG_USB_MON=y

But, when I try and cat /var/log/dmesages i get a messages:

cat: can't open '/var/log/dmesg': No such file or directory

Did you read the "Documentation/usb/usbmon.txt" in the kernel source tree
how to make use of the USB_MON feature?

Hi Juergen,

I'm not at usbmon yet. I first want to debug the usb gadgets then I will
try the host side. But when I try debug the usb gadgets using:

cat /var/log/dmesg

I get:

cat: can't open '/var/log/dmesg': No such file or directory

If you are using PTXdist there is no file called that in  /var/log

Either just type dmesg

or

/var/log/messages and use an editor to look at it.

Oops, or are those options suppose to change the logging behaviour?

As Dave already said: the "dmesg" tool shows you the kernel messages. They
are also visible on the kernel console (add 'debug' to your kernel command
line or run 'dmesg -n8' to see the debug as well). Or enable/start the
'syslogd' and 'klogd' to get the log-files in '/var/log'