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Darwin 0.2 Driver Kit

		lono driver config internals
		
* IODeviceDescription has new ivar, IOConfigTable *configTable.

* In kernel, IOConfigTable's _private ivar merely points to a char array
  which consists of the contents of a device instance file. 
  
* kern_dev.dconf, a dev_conf_t, will become a pointer to IODeviceDescription.
  (Note that nrw should probably do this too). For now, kern_dev will 
  have both.
  
* Kernel IOConfigTable will use the routines in config_table.c to parse 
  the config table text.
  
* There's a static copy of the *current system config table" in 
  KERNBOOTSTRUCT. That's what is returned in _IOGetSystemConfig().
  
* boot sequence
{
  	booter writes KERNBOOTSTRUCT to ??somewhere??
  	kernel comes up, eventually calls:
 	autoconf() {
		registerIndirClasses();	// registers SCSIDisk, etc. 
		probeNativeDevices();	// see below
		probeHardware(); 	// nop on i386
		probeDirectDevices();	// nop on i386
		probePseudoDevices();	// starts up EventDriver, etc.
	}
  
	/* 
	 * At this time, kernel can access boot device (at least).
	 * rc starts running; driverLoader starts up and does the rest of this.
	 */
	for each device in System config's "Boot Drivers" list {
		for each instance > 0 {
			/*
			 * Booter only loads in instance 0.
			 */
	   		IOLoadDevice();
		}
	}
     
	for each driver in System config's "Active Drivers" list {
		if there's a .o {
			kern_load it;
		}
		for each instance {
			IOLoadDevice();
		}
	}
}

/*
 * This is the kernel's routine which configures and probes the boot 
 * device and possibly additional drivers which either the booter passes 
 * in config table info for, or which have statically declared config 
 * tables.
 */
probeNativeDevices() {
  	for each config table passed in from booter {
		create an IODeviceDescription;
		probe the associated driver;
	}
	for each statically configured device {
		/*
		 * This is temporary, for internal development only 
		 */
		create an IODeviceDescription;
		probe the associated driver;
	}
}

.......................

call graph in autoconfg_i386

IOProbeDriver
	configureThread
		configureDriver
			configTableToClassName (config_table.c)
			configureDriverClass
			
probeNativeDevices
	configureDriver
		configDataToClassName()	(config_table.c)
		configureDriverClass

probePseudoDevices
	probeClass
		configureDriverClass
		
configureDriverClass
	configDataToDev()	(config_table.c)
	[IOEISADeviceDescription _initFromKernDev:]
	[devDesc setConfigTable:]
	[devDesc setDevicePort:];
	[devDesc setDeviceMaster:];
	[IODevice addLoadedClass];
	
.....................
functions to keep in autoconf_i386

/* called by MI probePseudoDevices() */
BOOL probeClass(port_name_t deviceMasterUport,
	IODeviceNumber devNum,
	const char *className,
	IODeviceDescription **deviceDescP);	

/* 
 * Called from MD probeNativeDevices() and from configureThread(), the
 * IOTask version of IOProbeDriver().
 */
static BOOL configureDriver(const char *configData, port_t deviceMaster);

/*
 * Given a class name and an IOConfigTable,
 * create a kern_dev and an IODeviceDescription and probe the class. 
 * This is used both at boot time - for the boot device and (temporarily) 
 * any native drivers with static config tables - and by IOProbeDriver().
 */
static BOOL configureDriverClass(const char *className, 
	IOConfigTable *configData, 
	port_t deviceMaster);



......................
to do (2 Feb 93)

* add pointer to IODeviceDescription to kern_dev_t. DONE
* when creating kern_dev, also create IODeviceDescription if valid 
  IOConfigTable exists. DONE
* Move relevant stuff from configTable.c to IOEISADeviceDescription.
* configureDriverClass() should take an (IOConfigTable *) instead of
  char *configData. 

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