Return to autoconfigInternal CVS log

Up to [Apple Darwin 0.x] / driverkit / notes

Annotation of driverkit/notes/autoconfigInternal, revision 1.1.1.1

1.1       root        1: Internal autoconfig
                      2: 
                      3: * kern_dev_t - a linked list. Starts empty. Add to it on detection
                      4:   of valid dev_type. Never free. Why should we? Probably don't need
                      5:   ref_count!
                      6: 
                      7: * need configurable table mapping dev_types to classes, with common
                      8:   probe: function.
                      9:   
                     10:   indirectDevices are the classes which need to be probed with the
                     11:   the id of the device. In internalDevMap, this is a null-terminated
                     12:   array of strings.
                     13:        
                     14:        eg      className = "SCSIController"
                     15:                indirectDevices = "SCSIDisk", "SCSITape", 
                     16:                        "SCSIGeneric", NULL.
                     17:                        
                     18:   struct internalDevMap {
                     19:        const char      *className;
                     20:        const char      *indirectDevices[];
                     21:        slot_id_t       slot_id;
                     22:        dev_id_t        dev_id;
                     23:   }
                     24:   
                     25: * Need need a way to probe 'devices' which don't need hardware, like using
                     26:   a list of internalDevMaps with invalid slot/dev ids.
                     27:   
                     28:   struct pseudoDevice {
                     29:        const char      *className;
                     30:        const char      *indirectDevices[];
                     31:   }
                     32:   
                     33: /*
                     34:  * This routine runs as a thread in IOTask so that it can allocate a
                     35:  * device_master port which can be object_copyin'd during 
                     36:  * register_device_master. Then, all of the drivers in IOTask can share 
                     37:  * this port.
                     38:  */
                     39: autoconfigInternal() {
                     40:     init kern_dev_list;
                     41:     allocate device_master, register via register_device_master();
                     42:     
                     43:     /*
                     44:      * Create a kern_dev_t for each piece of hardware, including native
                     45:      * devices and NextBus devices.
                     46:      */
                     47:     for each native dev_number {
                     48:        if valid dev_type {
                     49:            create a kern_dev_t for it {
                     50:                init dev_number, phys params;
                     51:                all else = null/empty;
                     52:            }
                     53:        }
                     54:        add to kern_dev_list;
                     55:     }
                     56:     
                     57:     for each NextBus board {
                     58:         if slot device
                     59:            create a kern_dev_t for it;
                     60:        else
                     61:            for each valid dev_type
                     62:                create a kern_dev_t for it;
                     63:     }
                     64:     
                     65:     /*
                     66:      * Start up each device's driver.
                     67:      */
                     68:     for each elt in kern_dev_list {
                     69:        if an internalDevMap exists for this slot/dev {
                     70:            if [className probe:dev_number deviceMaster:masterPort] {
                     71:                mark kern_dev inUse;  // should be done by driver via
                     72:                                      // dev_port_create()
                     73:                foreach indirectDevice {
                     74:                    [indirectDevice probe:directDevice];
                     75:                }
                     76:            }
                     77:        }
                     78:     }
                     79:     
                     80:     /*
                     81:      * Start up pseudoDevices.
                     82:      */
                     83:     for each elt in pseudoDevice array {
                     84:        if [className probe] {
                     85:            foreach indirectDevice {
                     86:                [indirectDevice probe:directDevice];
                     87:            }
                     88:        }
                     89:     }
                     90: }
                     91: 
                     92: Questions
                     93: 
                     94: * how to pass device_master port to internal drivers? What ports does a 
                     95:   kernel thread have access to when it starts?
                     96: 
                     97: * Are driver threads in the kernel task, or threads in a separate task?
                     98: 
                     99: * Do the calls to the dma module have to be in a thread, instead of in
                    100:   probe: (in kernel's autoconf context)? Does mach_user_internal work for
                    101:   threads in kernel task? Should IOThreadFork() fork threads off of the
                    102:   kernel task, or a separate one?
                    103:   

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.