GDB - hardware server

Hi,
we have 3 different target descriptions for the same target.

gdb has been built for all the 3 configurations but the 1st target
configuration is the default description. we are able to set configurations
from executable files but how to set the target descriptions from the
contents of the server.

tar remote host:port ,can I set the target description based on the
contents[like arch,register size..]  from the hardware server.I can only
see the comparison of what gdb is expecting and what gdb is getting from
the server. is there a way to change the gdb target descriptions from the
contents of server ?

Thanks for the help.

Mahesh B