platform关系

start_kernel

rest_init

kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);

do_basic_setup

    --init_tmpfs();
    driver_init();

void __init driver_init(void)
{
    /* These are the core pieces */
    devtmpfs_init();
    devices_init();
    buses_init();
    classes_init();
    firmware_init();
    hypervisor_init();

    /* These are also core pieces, but must come after the
     * core core pieces.
     */
    platform_bus_init();
    system_bus_init();
    cpu_dev_init();
    memory_dev_init();
}
 

int __init platform_bus_init(void)
{

    device_register(&platform_bus);
    bus_register(&platform_bus_type);
}

1-1device_register

struct device platform_bus = {
    .init_name    = "platform",
};

int device_register(struct device *dev)
{
    device_initialize(dev);
    return device_add(dev);
}

 

 

1-2bus_register

 

 

struct device platform_bus = {
    .init_name    = "platform",
};

 

struct device {
    struct device        *parent;

    struct device_private    *p;

    struct kobject kobj;
    const char        *init_name; /* initial name of the device */
    struct device_type    *type;

    struct mutex        mutex;    /* mutex to synchronize calls to
                     * its driver.
                     */

    struct bus_type    *bus;        /* type of bus device is on */
    struct device_driver *driver;    /* which driver has allocated this
                       device */
    void        *platform_data;    /* Platform specific data, device
                       core doesn't touch it */
    struct dev_pm_info    power;

#ifdef CONFIG_NUMA
    int        numa_node;    /* NUMA node this device is close to */
#endif
    u64        *dma_mask;    /* dma mask (if dma'able device) */
    u64        coherent_dma_mask;/* Like dma_mask, but for
                         alloc_coherent mappings as
                         not all hardware supports
                         64 bit addresses for consistent
                         allocations such descriptors. */

    struct device_dma_parameters *dma_parms;

    struct list_head    dma_pools;    /* dma pools (if dma'ble) */

    struct dma_coherent_mem    *dma_mem; /* internal for coherent mem
                         override */
    /* arch specific additions */
    struct dev_archdata    archdata;
#ifdef CONFIG_OF
    struct device_node    *of_node;
#endif

    dev_t            devt;    /* dev_t, creates the sysfs "dev" */

    spinlock_t        devres_lock;
    struct list_head    devres_head;

    struct klist_node    knode_class;
    struct class        *class;
    const struct attribute_group **groups;    /* optional groups */

    void    (*release)(struct device *dev);
};