Retrieving CUSTOM information

UnixWare 7 MDI drivers define parameters that can be modified by users through CUSTOM variables coded in their bcfg(4dsp) files rather than in their Space.c(4dsp) and space.h files. Drivers should be coded to access this information according to the following guidelines:

• Resource manager parameter names (defined in the first line of the CUSTOM definitions) must be less than 11 characters.

• Remember that the parameter value will not be supplied if the netcfg(1M) command is run in silent mode. The driver should define a reasonable default case. If the parameter value is not supplied, the driver should issue the cmn_err(D3) function with the CE_NOTE argument to display the default setting that the driver will use. Note that CUSTOM parameters are set for Network Installation. If the bcfg file indicates that the card uses the ISA bus, the user is prompted to enter applicable ISA card information from the bcfg file before beginning the network installation.

• Default values for CUSTOM parameters should be listed first in the list of values.

• All CUSTOM parameters that are retrieved from the resource manager database are interpreted as an ASCII string. For example, if the CUSTOM entry in the bcfg file for the foo driver starts:

     CUSTOM_NUM=1
     
  
     CUSTOM[1]='
     CABLE_TYPE
     1 0 0
     AUI BNC TP
     Cable Type
     ...
  

  The foo driver's _load(D2mdi) entry point routine should include code such as the following:

     char cable_str[64];
     struct cm_args cm_args;
     unsigned int foo_nunit;
     
  
     foo_nunit = cm_getnbrd("foo");
     if (foo_nunit == 0) {
        cmn_err(CE_WARN, "fooinit: can't find foo in resmgr");
        return(ENODEV);
     }
     
  
     for (i = 0; i < foo_nunit; i++) {
        cm_args.cm_key = cm_getbrdkey("foo", i);
        cm_args.cm_n = 0;
        cm_args.cm_param = "CABLE_TYPE";
        cm_args.cm_val = cable_str;
        cm_args.cm_vallen = sizeof(cable_str);
        if (ret = cm_getval(&cm_args)) {
           if (ret != ENOENT)
              cmn_err(CE_CONT, "fooinit: cm_getval(CABLE_TYPE) failed\n");
           continue;
        } else {
           switch(cable_str[0]) {
              case '0':
                 foodev[i].xcvr = 0;
                 break;
              case '1':
                 foodev[i].xcvr = 1;
                 break;
              default:
                 cmn_err (CE_CONT,
                    "fooinit: board %d has unknown CABLE_TYPE %s in resmgr\n",
                    i, cable_str);
                 continue;
           }
        }
        ...retrieve other parameters...
     }