All parameters are case sensitive, be careful.

winpart parameter 
This must be specified in append, it is the partition where the configuration file is.

winpartfs parameter
This is an obsolete parameter which specify the fstype of the partition winpart.

conf parameter
Path of the configuration file.
By default, if it isn't specified it will check for linux/bootconf.txt on winpart or stopping the process.
Note that it isn't \ but / for paths...
You must use this parameter without c:, d:, e: ... 
The first / is not required. Do not forget that it is case sentitive.