How can I debug an error on a driver attach ? I'm trying this dtrace -Fn 'fbt:vioif:vioif_attach:return { printf( "%x %d",arg0, arg1); }'

neirac: If it's returning something other than DDI_SUCCESS you'll want to look at log output (::msgbuf) and if that doesn't help you'll need to walk backwards in the source for that function and figure out why it's not working