BSD 开发笔记

freeBSD 还真是闭塞,资料太少~~


// char driver
     struct cdev *
     make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
     const char *fmt, ...)
     conf.h: struct cdevsw ; struct cdev

地址空间映射
    ioremap == pmap_mapdev
注册中断
  A：   bus_setup_intr
        intr_event_add_handler
 
  B：   cpu_establish_hardintr
        internal: (1)intr_event_create
                  (2)intr_event_add_handler
关闭所有中端
   splhigh
   splx
拷贝数据      
    copyin
    copyout
    uiomove
Poll 实现
   selrecord
   selwakeuppri
   selwakeup
mmap实现: ???
   1)phisical addr map:
        typedef int d_mmap_t(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr,
                int nprot);
         paddr = physical address
   2)内存
       call  vm_mmap

内核线程创建
    kproc_create(old： kthread_create)
    睡眠/唤醒
        msleep,msleep_spin,pause,tsleep;wakeup.
        mtx_sleep
        rw_sleep
        sx_sleep       
初始进程栈：
      /* Steal thread0 kstack.*/
       kstack0 = pmap_steal_memory(KSTACK_PAGES << PAGE_SHIFT);
      ////LINUX/////
       struct task_struct init_task = INIT_TASK(init_task);
      ////////////////////////////////
内存分配
        物理内存分页 struct vm_page
        //
        整页      contigmalloc    vtophys
        DMA 分配  bus_dmamem_alloc
        //
        初始化：mi_startup->vm_mem_init->vm_page_startup->vm_phys_add_page 
             page to physical: VM_PAGE_TO_PHYS
        物理page的预留：
         new_end = trunc_page(end - page_range * sizeof(struct vm_page));
        全局变量记录物理内存 physmem， phys_avail[]//修订

软中断
    int swi_add(struct intr_event **eventp, const char *name, driver_intr_t handler,
        void *arg, int pri, enum intr_type flags, void **cookiep)
    swi_sched
    swi_remove

任务队列
    taskqueue_create   
    taskqueue_start_threads + taskqueue_thread_enqueue// (taskqueue_enqueue+taskqueue_run）
    Difference: taskqueue_thread_enqueue / taskqueue_enqueue
    TASK_INIT
    taskqueue_drain     taskqueue_free
网络驱动
    //网络软中断
     swi_net->netisr_queue_workstream :: raise by NWS_SIGNAL
    //network driver.
    if_var.c:struct ifnet ;
    ifp->if_transmit = xxx_tx;// write code  

    if_ethersubr.c||ether_ifattach:
    ifp->if_output = ether_output;
    ifp->if_input = ether_input; // call this
  
    ether_output->ether_output_frame->((ifp->if_transmit)(ifp, m));     
    pf_test->pf_route->if_output  
    ether_input->ether_demux->(ip_fastforward return m, will not handle)==>
    ef_input->netisr_dispatch...>netisr_queue_internal
    //NAPI通过 taskqueue_start_threads实现