这个代码调试，你首先要保证你的udc驱动没用问题，这个有些矛盾，应为我本来要用gadget驱动来调试udc驱动，结果反过来了。 这是在zero基础改的，大概的改动 1. 去掉loop。
2. sink的读写去掉了。 3. 增加了一个misc，通过fs去读写数据。 4. setup的特殊请求去掉了。 之前的文章已经把大部分的东西说完了，所以代码没有太多的注释。请结合之前的文章阅读。 我用了一个完成量，在没有数据时，读可能会死在那。这个可以优化一下，我就不做了。 还有就是主机是虚拟机的usb，linux-2.6.18（无耻的告诉你就是usb-skeleton驱动），gadget是板子的，linux-3.2.36
gadget_transfer.c //linux-3.2.36
/* #define VERBOSE_DEBUG */ #include #include #include #include #include #include #include #include #include #define CONFIG_USB_GADGET_VBUS_DRAW 500 #include "composite.c" #include "usbstring.c" #include "config.c" #include "epautoconf.c" #define BUFLEN 4096 struct f_sourcesink { struct usb_function function; struct usb_ep *in_ep; struct usb_ep *out_ep; struct completion gdt_completion; char data[BUFLEN]; unsigned actual;//数据实际长度 }; static inline struct f_sourcesink *func_to_ss(struct usb_function *f) { return container_of(f, struct f_sourcesink, function); } /*-------------------------------------------------------------------------*/ //接口描述符 static struct usb_interface_descriptor source_sink_intf = { .bLength = sizeof source_sink_intf, .bDescriptorType = USB_DT_INTERFACE, .bNumEndpoints = 2, .bInterfaceClass = USB_CLASS_VENDOR_SPEC, /* .iInterface = DYNAMIC */ }; /* full speed support: */ //全速设备端点描述符 static struct usb_endpoint_descriptor fs_source_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_IN, .bmAttributes = USB_ENDPOINT_XFER_BULK, }; static struct usb_endpoint_descriptor fs_sink_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_OUT, .bmAttributes = USB_ENDPOINT_XFER_BULK, }; static struct usb_descriptor_header *fs_source_sink_descs[] = { (struct usb_descriptor_header *) &source_sink_intf, (struct usb_descriptor_header *) &fs_sink_desc, (struct usb_descriptor_header *) &fs_source_desc, NULL, }; /* high speed support: */ //高速设备端点描述符 static struct usb_endpoint_descriptor hs_source_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(512), }; static struct usb_endpoint_descriptor hs_sink_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(512), }; static struct usb_descriptor_header *hs_source_sink_descs[] = { (struct usb_descriptor_header *) &source_sink_intf, (struct usb_descriptor_header *) &hs_source_desc, (struct usb_descriptor_header *) &hs_sink_desc, NULL, }; /* function-specific strings: */ static struct usb_string strings_sourcesink[] = { [0].s = "source and sink data", { } /* end of list */ }; static struct usb_gadget_strings stringtab_sourcesink = { .language = 0x0409, /* en-us */ .strings = strings_sourcesink, }; static struct usb_gadget_strings *sourcesink_strings[] = { &stringtab_sourcesink, NULL, }; /*-------------------------------------------------------------------------*/ static const char longname[] = "Gadget gadget_transfer"; #define DRIVER_VENDOR_NUM 0x0ff0 #define DRIVER_PRODUCT_NUM 0x0ff0 /*-------------------------------------------------------------------------*/ //usb设备描述符 static struct usb_device_descriptor device_desc = { .bLength = sizeof device_desc, .bDescriptorType = USB_DT_DEVICE, .bcdUSB = cpu_to_le16(0x0200), .bDeviceClass = USB_CLASS_VENDOR_SPEC, .idVendor = cpu_to_le16(DRIVER_VENDOR_NUM), .idProduct = cpu_to_le16(DRIVER_PRODUCT_NUM), .bNumConfigurations = 2, }; /* string IDs are assigned dynamically */ #define STRING_MANUFACTURER_IDX 0 #define STRING_PRODUCT_IDX 1 #define STRING_SERIAL_IDX 2 static char manufacturer[50]; /* default serial number takes at least two packets */ static char serial[] = "0123456789.0123456789.0123456789"; static struct usb_string strings_dev[] = { [STRING_MANUFACTURER_IDX].s = manufacturer, [STRING_PRODUCT_IDX].s = longname, [STRING_SERIAL_IDX].s = serial, { } /* end of list */ }; static struct usb_gadget_strings stringtab_dev = { .language = 0x0409, /* en-us */ .strings = strings_dev, }; static struct usb_gadget_strings *dev_strings[] = { &stringtab_dev, NULL, }; /*-------------------------------------------------------------------------*/ struct usb_request *alloc_ep_req(struct usb_ep *ep) { struct usb_request *req; //看过之前udc的request，就知道这个就是个kzalloc req = usb_ep_alloc_request(ep, GFP_ATOMIC); if (req) { req->length = BUFLEN; req->buf = kmalloc(BUFLEN, GFP_ATOMIC); if (!req->buf) { usb_ep_free_request(ep, req); req = NULL; } } return req; } void free_ep_req(struct usb_ep *ep, struct usb_request *req) { kfree(req->buf); usb_ep_free_request(ep, req); } static void disable_ep(struct usb_composite_dev *cdev, struct usb_ep *ep) { int value; if (ep->driver_data) { value = usb_ep_disable(ep); ep->driver_data = NULL; } } void disable_endpoints(struct usb_composite_dev *cdev, struct usb_ep *in, struct usb_ep *out) { disable_ep(cdev, in); disable_ep(cdev, out); } /*-------------------------------------------------------------------------*/ static int __init sourcesink_bind(struct usb_configuration *c, struct usb_function *f) { struct usb_composite_dev *cdev = c->cdev; struct f_sourcesink *ss = func_to_ss(f); int id; id = usb_interface_id(c, f); if (id < 0) return id; source_sink_intf.bInterfaceNumber = id; ss->in_ep = usb_ep_autoconfig(cdev->gadget, &fs_source_desc); if (!ss->in_ep) { autoconf_fail: return -ENODEV; } ss->in_ep->driver_data = cdev; /* claim */ ss->out_ep = usb_ep_autoconfig(cdev->gadget, &fs_sink_desc); if (!ss->out_ep) goto autoconf_fail; ss->out_ep->driver_data = cdev; /* claim */ /* support high speed hardware */ if (gadget_is_dualspeed(c->cdev->gadget)) { hs_source_desc.bEndpointAddress = fs_source_desc.bEndpointAddress; hs_sink_desc.bEndpointAddress = fs_sink_desc.bEndpointAddress; f->hs_descriptors = hs_source_sink_descs; } return 0; } static void sourcesink_unbind(struct usb_configuration *c, struct usb_function *f) { kfree(func_to_ss(f)); } static void disable_source_sink(struct f_sourcesink *ss) { struct usb_composite_dev *cdev; cdev = ss->function.config->cdev; disable_endpoints(cdev, ss->in_ep, ss->out_ep);//就是disable了in和out } static int enable_source_sink(struct usb_composite_dev *cdev, struct f_sourcesink *ss) { int result = 0; struct usb_ep *ep; /* one endpoint writes (sources) zeroes IN (to the host) */ ep = ss->in_ep; result = config_ep_by_speed(cdev->gadget, &(ss->function), ep); if (result) return result; result = usb_ep_enable(ep); if (result < 0) return result; ep->driver_data = ss; /* one endpoint reads (sinks) anything OUT (from the host) */ ep = ss->out_ep; result = config_ep_by_speed(cdev->gadget, &(ss->function), ep); if (result) goto fail; result = usb_ep_enable(ep); if (result < 0) goto fail; ep->driver_data = ss; return result; fail: ep = ss->in_ep; usb_ep_disable(ep); ep->driver_data = NULL; return result; } static int sourcesink_set_alt(struct usb_function *f, unsigned intf, unsigned alt) { struct f_sourcesink *ss = func_to_ss(f); struct usb_composite_dev *cdev = f->config->cdev; /* we know alt is zero */ if (ss->in_ep->driver_data) disable_source_sink(ss); return enable_source_sink(cdev, ss); } static void sourcesink_disable(struct usb_function *f) { struct f_sourcesink *ss = func_to_ss(f); disable_source_sink(ss); } /*-------------------------------------------------------------------------*/ static struct f_sourcesink *ss; static int __init sourcesink_bind_config(struct usb_configuration *c) { int status; ss = kzalloc(sizeof *ss, GFP_KERNEL); if (!ss) return -ENOMEM; init_completion(&ss->gdt_completion); ss->function.name = "source/sink"; ss->function.descriptors = fs_source_sink_descs; ss->function.bind = sourcesink_bind; ss->function.unbind = sourcesink_unbind; ss->function.set_alt = sourcesink_set_alt; ss->function.disable = sourcesink_disable; status = usb_add_function(c, &ss->function); if (status) kfree(ss); return status; } static int sourcesink_setup(struct usb_configuration *c, const struct usb_ctrlrequest *ctrl) { return 0; } static struct usb_configuration sourcesink_driver = { .label = "source/sink", .strings = sourcesink_strings, .setup = sourcesink_setup, .bConfigurationValue = 3, .bmAttributes = USB_CONFIG_ATT_SELFPOWER, /* .iConfiguration = DYNAMIC */ }; /** * sourcesink_add - add a source/sink testing configuration to a device * @cdev: the device to support the configuration */ static int __init sourcesink_add(struct usb_composite_dev *cdev) { int id; /* allocate string ID(s) */ id = usb_string_id(cdev); if (id < 0) return id; strings_sourcesink[0].id = id; source_sink_intf.iInterface = id; sourcesink_driver.iConfiguration = id; return usb_add_config(cdev, &sourcesink_driver, sourcesink_bind_config); } struct gadget_misc { struct miscdevice miscdevp; }; static void source_sink_complete(struct usb_ep *ep, struct usb_request *req) { int status = req->status; switch (status) { case 0: /* normal completion? */ case -ECONNABORTED: /* hardware forced ep reset */ case -ECONNRESET: /* request dequeued */ case -ESHUTDOWN: /* disconnect from host */ if (ep == ss->out_ep) { memset(ss->data, 0, BUFLEN); memcpy(ss->data, req->buf, req->actual); ss->actual = req->actual; } break; case -EOVERFLOW: default: case -EREMOTEIO: break; } //没有继续 free_ep_req(ep, req); complete(&ss->gdt_completion); } static int gadget_transfer_open(struct inode *inode, struct file *filp) { return 0; } static ssize_t gadget_transfer_read(struct file *filp, char __user * buf, size_t count, loff_t * f_pos) { struct usb_request *req; int ret; req = alloc_ep_req(ss->out_ep); if (!req) { ret = -ENOMEM; goto fail; } req->complete = source_sink_complete; ret = usb_ep_queue(ss->out_ep, req, GFP_ATOMIC); if (ret) { free_ep_req(ss->out_ep, req); goto fail; } wait_for_completion(&ss->gdt_completion); ss->actual = (count < ss->actual) ? count : ss->actual; if (copy_to_user (buf, ss->data, ss->actual)) //拷贝读取的数据到用户空间 { ret = -EFAULT; goto fail; } return ss->actual; fail: return ret; } static ssize_t gadget_transfer_write(struct file *filp, const char __user * buf, size_t count, loff_t * f_pos) { struct usb_request *req; int ret; req = alloc_ep_req(ss->in_ep); if (!req) { return -ENOMEM; } req->length = (count < BUFLEN) ? count : BUFLEN; if (copy_from_user (req->buf, buf, req->length)) //拷贝读取的数据到用户空间 { ret = -EFAULT; goto fail; } req->complete = source_sink_complete; ret = usb_ep_queue(ss->in_ep, req, GFP_ATOMIC); if (ret) { goto fail; } wait_for_completion(&ss->gdt_completion); return req->actual; fail: free_ep_req(ss->in_ep, req); return ret; } static int gadget_transfer_release(struct inode *inode, struct file *filp) { return 0; } static struct file_operations gadget_transfer_fops = { owner:THIS_MODULE, open:gadget_transfer_open, read:gadget_transfer_read, write:gadget_transfer_write, release:gadget_transfer_release, }; static struct miscdevice gadget_transfer_misc = { MISC_DYNAMIC_MINOR, "gadget_transfer", &gadget_transfer_fops, }; /*-------------------------------------------------------------------------*/ static int __init gadget_transfer_bind(struct usb_composite_dev *cdev) { struct usb_gadget *gadget = cdev->gadget; int id; int ret = 0; ret = misc_register(&gadget_transfer_misc); if (ret) { goto fail_reg; } //各字符串描述符的引索 id = usb_string_id(cdev);//这个东西之前有说过，就是cdev->next_string_id++返回，怕id冲突 if (id < 0) return id; strings_dev[STRING_MANUFACTURER_IDX].id = id; device_desc.iManufacturer = id; id = usb_string_id(cdev); if (id < 0) return id; strings_dev[STRING_PRODUCT_IDX].id = id; device_desc.iProduct = id; id = usb_string_id(cdev); if (id < 0) return id; strings_dev[STRING_SERIAL_IDX].id = id; device_desc.iSerialNumber = id; sourcesink_add(cdev); device_desc.bcdDevice = cpu_to_le16(0x0200 + 0x12); snprintf(manufacturer, sizeof manufacturer, "%s %s with %s", init_utsname()->sysname, init_utsname()->release, gadget->name); fail_reg: return 0; } static int gadget_transfer_unbind(struct usb_composite_dev *cdev) { misc_deregister(&gadget_transfer_misc); return 0; } static struct usb_composite_driver gadget_transfer_driver = { .name = "gadget_transfer", .dev = &device_desc, .strings = dev_strings, .max_speed = USB_SPEED_SUPER, .unbind = gadget_transfer_unbind, }; MODULE_LICENSE("GPL"); static int __init init(void) { return usb_composite_probe(&gadget_transfer_driver, gadget_transfer_bind); } module_init(init); static void __exit cleanup(void) { usb_composite_unregister(&gadget_transfer_driver); } module_exit(cleanup);
usb-skeleton.c //linux-2.6.18 就改了 //#define USB_SKEL_VENDOR_ID    0x0ff0
//#define USB_SKEL_PRODUCT_ID    0x0ff0 /* * USB Skeleton driver - 2.0 * * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation, version 2. * * This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c * but has been rewritten to be easy to read and use, as no locks are now * needed anymore. * */ #include #include #include #include #include #include #include #include /* Define these values to match your devices */ #define USB_SKEL_VENDOR_ID 0x0ff0 #define USB_SKEL_PRODUCT_ID 0x0ff0 /* table of devices that work with this driver */ static struct usb_device_id skel_table [] = { { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) }, { } /* Terminating entry */ }; MODULE_DEVICE_TABLE (usb, skel_table); /* Get a minor range for your devices from the usb maintainer */ #define USB_SKEL_MINOR_BASE 192 /* our private defines. if this grows any larger, use your own .h file */ #define MAX_TRANSFER ( PAGE_SIZE - 512 ) #define WRITES_IN_FLIGHT 8 /* Structure to hold all of our device specific stuff */ struct usb_skel { struct usb_device * udev; /* the usb device for this device */ struct usb_interface * interface; /* the interface for this device */ struct semaphore limit_sem; /* limiting the number of writes in progress */ unsigned char * bulk_in_buffer; /* the buffer to receive data */ size_t bulk_in_size; /* the size of the receive buffer */ __u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */ __u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */ struct kref kref; }; #define to_skel_dev(d) container_of(d, struct usb_skel, kref) static struct usb_driver skel_driver; static void skel_delete(struct kref *kref) { struct usb_skel *dev = to_skel_dev(kref); usb_put_dev(dev->udev); kfree (dev->bulk_in_buffer); kfree (dev); } static int skel_open(struct inode *inode, struct file *file) { struct usb_skel *dev; struct usb_interface *interface; int subminor; int retval = 0; subminor = iminor(inode); interface = usb_find_interface(&skel_driver, subminor); if (!interface) { err ("%s - error, can't find device for minor %d", __FUNCTION__, subminor); retval = -ENODEV; goto exit; } dev = usb_get_intfdata(interface); if (!dev) { retval = -ENODEV; goto exit; } /* increment our usage count for the device */ kref_get(&dev->kref); /* save our object in the file's private structure */ file->private_data = dev; exit: return retval; } static int skel_release(struct inode *inode, struct file *file) { struct usb_skel *dev; dev = (struct usb_skel *)file->private_data; if (dev == NULL) return -ENODEV; /* decrement the count on our device */ kref_put(&dev->kref, skel_delete); return 0; } static ssize_t skel_read(struct file *file, char *buffer, size_t count, loff_t *ppos) { struct usb_skel *dev; int retval = 0; int bytes_read; dev = (struct usb_skel *)file->private_data; /* do a blocking bulk read to get data from the device */ retval = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr), dev->bulk_in_buffer, min(dev->bulk_in_size, count), &bytes_read, 10000); memset(buffer, 0, sizeof(buffer)); /* if the read was successful, copy the data to userspace */ if (!retval) { if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read)) retval = -EFAULT; else retval = bytes_read; } return retval; } static void skel_write_bulk_callback(struct urb *urb, struct pt_regs *regs) { struct usb_skel *dev; dev = (struct usb_skel *)urb->context; /* sync/async unlink faults aren't errors */ if (urb->status && !(urb->status == -ENOENT || urb->status == -ECONNRESET || urb->status == -ESHUTDOWN)) { dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status); } /* free up our allocated buffer */ usb_buffer_free(urb->dev, urb->transfer_buffer_length, urb->transfer_buffer, urb->transfer_dma); up(&dev->limit_sem); } static ssize_t skel_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos) { struct usb_skel *dev; int retval = 0; struct urb *urb = NULL; char *buf = NULL; size_t writesize = min(count, (size_t)MAX_TRANSFER); dev = (struct usb_skel *)file->private_data; /* verify that we actually have some data to write */ if (count == 0) goto exit; /* limit the number of URBs in flight to stop a user from using up all RAM */ if (down_interruptible(&dev->limit_sem)) { retval = -ERESTARTSYS; goto exit; } /* create a urb, and a buffer for it, and copy the data to the urb */ urb = usb_alloc_urb(0, GFP_KERNEL); if (!urb) { retval = -ENOMEM; goto error; } buf = usb_buffer_alloc(dev->udev, writesize, GFP_KERNEL, &urb->transfer_dma); if (!buf) { retval = -ENOMEM; goto error; } if (copy_from_user(buf, user_buffer, writesize)) { retval = -EFAULT; goto error; } /* initialize the urb properly */ usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), buf, writesize, skel_write_bulk_callback, dev); urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; /* send the data out the bulk port */ retval = usb_submit_urb(urb, GFP_KERNEL); if (retval) { err("%s - failed submitting write urb, error %d", __FUNCTION__, retval); goto error; } /* release our reference to this urb, the USB core will eventually free it entirely */ usb_free_urb(urb); exit: return writesize; error: usb_buffer_free(dev->udev, writesize, buf, urb->transfer_dma); usb_free_urb(urb); up(&dev->limit_sem); return retval; } static struct file_operations skel_fops = { .owner = THIS_MODULE, .read = skel_read, .write = skel_write, .open = skel_open, .release = skel_release, }; /* * usb class driver info in order to get a minor number from the usb core, * and to have the device registered with the driver core */ static struct usb_class_driver skel_class = { .name = "skel%d", .fops = &skel_fops, .minor_base = USB_SKEL_MINOR_BASE, }; static int skel_probe(struct usb_interface *interface, const struct usb_device_id *id) { struct usb_skel *dev = NULL; struct usb_host_interface *iface_desc; struct usb_endpoint_descriptor *endpoint; size_t buffer_size; int i; int retval = -ENOMEM; /* allocate memory for our device state and initialize it */ dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (dev == NULL) { err("Out of memory"); goto error; } kref_init(&dev->kref); sema_init(&dev->limit_sem, WRITES_IN_FLIGHT); dev->udev = usb_get_dev(interface_to_usbdev(interface)); dev->interface = interface; /* set up the endpoint information */ /* use only the first bulk-in and bulk-out endpoints */ iface_desc = interface->cur_altsetting; for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { endpoint = &iface_desc->endpoint[i].desc; if (!dev->bulk_in_endpointAddr && ((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN) && ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK)) { /* we found a bulk in endpoint */ buffer_size = le16_to_cpu(endpoint->wMaxPacketSize); dev->bulk_in_size = buffer_size; dev->bulk_in_endpointAddr = endpoint->bEndpointAddress; dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL); if (!dev->bulk_in_buffer) { err("Could not allocate bulk_in_buffer"); goto error; } } if (!dev->bulk_out_endpointAddr && ((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT) && ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK)) { /* we found a bulk out endpoint */ dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; } } if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) { err("Could not find both bulk-in and bulk-out endpoints"); goto error; } /* save our data pointer in this interface device */ usb_set_intfdata(interface, dev); /* we can register the device now, as it is ready */ retval = usb_register_dev(interface, &skel_class); if (retval) { /* something prevented us from registering this driver */ err("Not able to get a minor for this device."); usb_set_intfdata(interface, NULL); goto error; } /* let the user know what node this device is now attached to */ info("USB Skeleton device now attached to USBSkel-%d", interface->minor); return 0; error: if (dev) kref_put(&dev->kref, skel_delete); return retval; } static void skel_disconnect(struct usb_interface *interface) { struct usb_skel *dev; int minor = interface->minor; /* prevent skel_open() from racing skel_disconnect() */ lock_kernel(); dev = usb_get_intfdata(interface); usb_set_intfdata(interface, NULL); /* give back our minor */ usb_deregister_dev(interface, &skel_class); unlock_kernel(); /* decrement our usage count */ kref_put(&dev->kref, skel_delete); info("USB Skeleton #%d now disconnected", minor); } static struct usb_driver skel_driver = { .name = "skeleton", .probe = skel_probe, .disconnect = skel_disconnect, .id_table = skel_table, }; static int __init usb_skel_init(void) { int result; /* register this driver with the USB subsystem */ result = usb_register(&skel_driver); if (result) err("usb_register failed. Error number %d", result); return result; } static void __exit usb_skel_exit(void) { /* deregister this driver with the USB subsystem */ usb_deregister(&skel_driver); } module_init (usb_skel_init); module_exit (usb_skel_exit); MODULE_LICENSE("GPL");
调试 板子执行
有些答应打印是我加的，不要管，还有我的内核usb这块什么都没选，所以加载的多。
有gadget_transfer设备文件   Windows的提示       虚拟机有0ff0:0ff0 usddevice

在虚拟机装载     板子提示   虚拟机

有个skel0 设备文件   虚拟机执行 如果板子不动作，最后   现在执行cat /dev/skel0 板子执行  
虚拟机  
反过来 板子读，虚拟机写  


当你拔去usb是你会发现/dev/skel0消失 基本就这样，下期会回到我的udc驱动上来，下期再见！