Rename existing rd_DASD parameter to rd_DASD_MOD. Document new rd_DASD
parameter handling.
.SH DASD
.TP
-.B rd_DASD=....
+.B rd_DASD_MOD=....
same syntax as the kernel module parameter (s390 only)
+.TP
+.B rd_DASD=<CCW address>[,readonly=X][,use_diag=X][,erplog=X][,failfast=X]
+activate DASD device at given CCW address and setting the sysfs attributes
+to the specified values
+
.SH ZFCP
.TP
.B rd_ZFCP=<zfcp adaptor device bus ID>,<WWPN>,<FCPLUN>