1 /* 2 * (C) Copyright 2008 - 2009 3 * Windriver, <www.windriver.com> 4 * Tom Rix <Tom.Rix@windriver.com> 5 * 6 * Copyright 2011 Sebastian Andrzej Siewior <bigeasy@linutronix.de> 7 * 8 * Copyright 2014 Linaro, Ltd. 9 * Rob Herring <robh@kernel.org> 10 * 11 * SPDX-License-Identifier: GPL-2.0+ 12 */ 13 #include <config.h> 14 #include <common.h> 15 #include <errno.h> 16 #include <fastboot.h> 17 #include <malloc.h> 18 #include <linux/usb/ch9.h> 19 #include <linux/usb/gadget.h> 20 #include <linux/usb/composite.h> 21 #include <linux/compiler.h> 22 #include <version.h> 23 #include <g_dnl.h> 24 #ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV 25 #include <fb_mmc.h> 26 #endif 27 #ifdef CONFIG_FASTBOOT_FLASH_NAND_DEV 28 #include <fb_nand.h> 29 #endif 30 31 #define FASTBOOT_VERSION "0.4" 32 33 #define FASTBOOT_INTERFACE_CLASS 0xff 34 #define FASTBOOT_INTERFACE_SUB_CLASS 0x42 35 #define FASTBOOT_INTERFACE_PROTOCOL 0x03 36 37 #define RX_ENDPOINT_MAXIMUM_PACKET_SIZE_2_0 (0x0200) 38 #define RX_ENDPOINT_MAXIMUM_PACKET_SIZE_1_1 (0x0040) 39 #define TX_ENDPOINT_MAXIMUM_PACKET_SIZE (0x0040) 40 41 #define EP_BUFFER_SIZE 4096 42 43 struct f_fastboot { 44 struct usb_function usb_function; 45 46 /* IN/OUT EP's and corresponding requests */ 47 struct usb_ep *in_ep, *out_ep; 48 struct usb_request *in_req, *out_req; 49 }; 50 51 static inline struct f_fastboot *func_to_fastboot(struct usb_function *f) 52 { 53 return container_of(f, struct f_fastboot, usb_function); 54 } 55 56 static struct f_fastboot *fastboot_func; 57 static unsigned int fastboot_flash_session_id; 58 static unsigned int download_size; 59 static unsigned int download_bytes; 60 static bool is_high_speed; 61 62 static struct usb_endpoint_descriptor fs_ep_in = { 63 .bLength = USB_DT_ENDPOINT_SIZE, 64 .bDescriptorType = USB_DT_ENDPOINT, 65 .bEndpointAddress = USB_DIR_IN, 66 .bmAttributes = USB_ENDPOINT_XFER_BULK, 67 .wMaxPacketSize = TX_ENDPOINT_MAXIMUM_PACKET_SIZE, 68 .bInterval = 0x00, 69 }; 70 71 static struct usb_endpoint_descriptor fs_ep_out = { 72 .bLength = USB_DT_ENDPOINT_SIZE, 73 .bDescriptorType = USB_DT_ENDPOINT, 74 .bEndpointAddress = USB_DIR_OUT, 75 .bmAttributes = USB_ENDPOINT_XFER_BULK, 76 .wMaxPacketSize = RX_ENDPOINT_MAXIMUM_PACKET_SIZE_1_1, 77 .bInterval = 0x00, 78 }; 79 80 static struct usb_endpoint_descriptor hs_ep_out = { 81 .bLength = USB_DT_ENDPOINT_SIZE, 82 .bDescriptorType = USB_DT_ENDPOINT, 83 .bEndpointAddress = USB_DIR_OUT, 84 .bmAttributes = USB_ENDPOINT_XFER_BULK, 85 .wMaxPacketSize = RX_ENDPOINT_MAXIMUM_PACKET_SIZE_2_0, 86 .bInterval = 0x00, 87 }; 88 89 static struct usb_interface_descriptor interface_desc = { 90 .bLength = USB_DT_INTERFACE_SIZE, 91 .bDescriptorType = USB_DT_INTERFACE, 92 .bInterfaceNumber = 0x00, 93 .bAlternateSetting = 0x00, 94 .bNumEndpoints = 0x02, 95 .bInterfaceClass = FASTBOOT_INTERFACE_CLASS, 96 .bInterfaceSubClass = FASTBOOT_INTERFACE_SUB_CLASS, 97 .bInterfaceProtocol = FASTBOOT_INTERFACE_PROTOCOL, 98 }; 99 100 static struct usb_descriptor_header *fb_runtime_descs[] = { 101 (struct usb_descriptor_header *)&interface_desc, 102 (struct usb_descriptor_header *)&fs_ep_in, 103 (struct usb_descriptor_header *)&hs_ep_out, 104 NULL, 105 }; 106 107 /* 108 * static strings, in UTF-8 109 */ 110 static const char fastboot_name[] = "Android Fastboot"; 111 112 static struct usb_string fastboot_string_defs[] = { 113 [0].s = fastboot_name, 114 { } /* end of list */ 115 }; 116 117 static struct usb_gadget_strings stringtab_fastboot = { 118 .language = 0x0409, /* en-us */ 119 .strings = fastboot_string_defs, 120 }; 121 122 static struct usb_gadget_strings *fastboot_strings[] = { 123 &stringtab_fastboot, 124 NULL, 125 }; 126 127 static void rx_handler_command(struct usb_ep *ep, struct usb_request *req); 128 static int strcmp_l1(const char *s1, const char *s2); 129 130 131 void fastboot_fail(char *response, const char *reason) 132 { 133 strncpy(response, "FAIL\0", 5); 134 strncat(response, reason, FASTBOOT_RESPONSE_LEN - 4 - 1); 135 } 136 137 void fastboot_okay(char *response, const char *reason) 138 { 139 strncpy(response, "OKAY\0", 5); 140 strncat(response, reason, FASTBOOT_RESPONSE_LEN - 4 - 1); 141 } 142 143 static void fastboot_complete(struct usb_ep *ep, struct usb_request *req) 144 { 145 int status = req->status; 146 if (!status) 147 return; 148 printf("status: %d ep '%s' trans: %d\n", status, ep->name, req->actual); 149 } 150 151 static int fastboot_bind(struct usb_configuration *c, struct usb_function *f) 152 { 153 int id; 154 struct usb_gadget *gadget = c->cdev->gadget; 155 struct f_fastboot *f_fb = func_to_fastboot(f); 156 const char *s; 157 158 /* DYNAMIC interface numbers assignments */ 159 id = usb_interface_id(c, f); 160 if (id < 0) 161 return id; 162 interface_desc.bInterfaceNumber = id; 163 164 id = usb_string_id(c->cdev); 165 if (id < 0) 166 return id; 167 fastboot_string_defs[0].id = id; 168 interface_desc.iInterface = id; 169 170 f_fb->in_ep = usb_ep_autoconfig(gadget, &fs_ep_in); 171 if (!f_fb->in_ep) 172 return -ENODEV; 173 f_fb->in_ep->driver_data = c->cdev; 174 175 f_fb->out_ep = usb_ep_autoconfig(gadget, &fs_ep_out); 176 if (!f_fb->out_ep) 177 return -ENODEV; 178 f_fb->out_ep->driver_data = c->cdev; 179 180 hs_ep_out.bEndpointAddress = fs_ep_out.bEndpointAddress; 181 182 s = getenv("serial#"); 183 if (s) 184 g_dnl_set_serialnumber((char *)s); 185 186 return 0; 187 } 188 189 static void fastboot_unbind(struct usb_configuration *c, struct usb_function *f) 190 { 191 memset(fastboot_func, 0, sizeof(*fastboot_func)); 192 } 193 194 static void fastboot_disable(struct usb_function *f) 195 { 196 struct f_fastboot *f_fb = func_to_fastboot(f); 197 198 usb_ep_disable(f_fb->out_ep); 199 usb_ep_disable(f_fb->in_ep); 200 201 if (f_fb->out_req) { 202 free(f_fb->out_req->buf); 203 usb_ep_free_request(f_fb->out_ep, f_fb->out_req); 204 f_fb->out_req = NULL; 205 } 206 if (f_fb->in_req) { 207 free(f_fb->in_req->buf); 208 usb_ep_free_request(f_fb->in_ep, f_fb->in_req); 209 f_fb->in_req = NULL; 210 } 211 } 212 213 static struct usb_request *fastboot_start_ep(struct usb_ep *ep) 214 { 215 struct usb_request *req; 216 217 req = usb_ep_alloc_request(ep, 0); 218 if (!req) 219 return NULL; 220 221 req->length = EP_BUFFER_SIZE; 222 req->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, EP_BUFFER_SIZE); 223 if (!req->buf) { 224 usb_ep_free_request(ep, req); 225 return NULL; 226 } 227 228 memset(req->buf, 0, req->length); 229 return req; 230 } 231 232 static int fastboot_set_alt(struct usb_function *f, 233 unsigned interface, unsigned alt) 234 { 235 int ret; 236 struct usb_composite_dev *cdev = f->config->cdev; 237 struct usb_gadget *gadget = cdev->gadget; 238 struct f_fastboot *f_fb = func_to_fastboot(f); 239 240 debug("%s: func: %s intf: %d alt: %d\n", 241 __func__, f->name, interface, alt); 242 243 /* make sure we don't enable the ep twice */ 244 if (gadget->speed == USB_SPEED_HIGH) { 245 ret = usb_ep_enable(f_fb->out_ep, &hs_ep_out); 246 is_high_speed = true; 247 } else { 248 ret = usb_ep_enable(f_fb->out_ep, &fs_ep_out); 249 is_high_speed = false; 250 } 251 if (ret) { 252 puts("failed to enable out ep\n"); 253 return ret; 254 } 255 256 f_fb->out_req = fastboot_start_ep(f_fb->out_ep); 257 if (!f_fb->out_req) { 258 puts("failed to alloc out req\n"); 259 ret = -EINVAL; 260 goto err; 261 } 262 f_fb->out_req->complete = rx_handler_command; 263 264 ret = usb_ep_enable(f_fb->in_ep, &fs_ep_in); 265 if (ret) { 266 puts("failed to enable in ep\n"); 267 goto err; 268 } 269 270 f_fb->in_req = fastboot_start_ep(f_fb->in_ep); 271 if (!f_fb->in_req) { 272 puts("failed alloc req in\n"); 273 ret = -EINVAL; 274 goto err; 275 } 276 f_fb->in_req->complete = fastboot_complete; 277 278 ret = usb_ep_queue(f_fb->out_ep, f_fb->out_req, 0); 279 if (ret) 280 goto err; 281 282 return 0; 283 err: 284 fastboot_disable(f); 285 return ret; 286 } 287 288 static int fastboot_add(struct usb_configuration *c) 289 { 290 struct f_fastboot *f_fb = fastboot_func; 291 int status; 292 293 debug("%s: cdev: 0x%p\n", __func__, c->cdev); 294 295 if (!f_fb) { 296 f_fb = memalign(CONFIG_SYS_CACHELINE_SIZE, sizeof(*f_fb)); 297 if (!f_fb) 298 return -ENOMEM; 299 300 fastboot_func = f_fb; 301 memset(f_fb, 0, sizeof(*f_fb)); 302 } 303 304 f_fb->usb_function.name = "f_fastboot"; 305 f_fb->usb_function.hs_descriptors = fb_runtime_descs; 306 f_fb->usb_function.bind = fastboot_bind; 307 f_fb->usb_function.unbind = fastboot_unbind; 308 f_fb->usb_function.set_alt = fastboot_set_alt; 309 f_fb->usb_function.disable = fastboot_disable; 310 f_fb->usb_function.strings = fastboot_strings; 311 312 status = usb_add_function(c, &f_fb->usb_function); 313 if (status) { 314 free(f_fb); 315 fastboot_func = f_fb; 316 } 317 318 return status; 319 } 320 DECLARE_GADGET_BIND_CALLBACK(usb_dnl_fastboot, fastboot_add); 321 322 static int fastboot_tx_write(const char *buffer, unsigned int buffer_size) 323 { 324 struct usb_request *in_req = fastboot_func->in_req; 325 int ret; 326 327 memcpy(in_req->buf, buffer, buffer_size); 328 in_req->length = buffer_size; 329 330 usb_ep_dequeue(fastboot_func->in_ep, in_req); 331 332 ret = usb_ep_queue(fastboot_func->in_ep, in_req, 0); 333 if (ret) 334 printf("Error %d on queue\n", ret); 335 return 0; 336 } 337 338 static int fastboot_tx_write_str(const char *buffer) 339 { 340 return fastboot_tx_write(buffer, strlen(buffer)); 341 } 342 343 static void compl_do_reset(struct usb_ep *ep, struct usb_request *req) 344 { 345 do_reset(NULL, 0, 0, NULL); 346 } 347 348 int __weak fb_set_reboot_flag(void) 349 { 350 return -ENOSYS; 351 } 352 353 static void cb_reboot(struct usb_ep *ep, struct usb_request *req) 354 { 355 char *cmd = req->buf; 356 if (!strcmp_l1("reboot-bootloader", cmd)) { 357 if (fb_set_reboot_flag()) { 358 fastboot_tx_write_str("FAILCannot set reboot flag"); 359 return; 360 } 361 } 362 fastboot_func->in_req->complete = compl_do_reset; 363 fastboot_tx_write_str("OKAY"); 364 } 365 366 static int strcmp_l1(const char *s1, const char *s2) 367 { 368 if (!s1 || !s2) 369 return -1; 370 return strncmp(s1, s2, strlen(s1)); 371 } 372 373 static void cb_getvar(struct usb_ep *ep, struct usb_request *req) 374 { 375 char *cmd = req->buf; 376 char response[FASTBOOT_RESPONSE_LEN]; 377 const char *s; 378 size_t chars_left; 379 380 strcpy(response, "OKAY"); 381 chars_left = sizeof(response) - strlen(response) - 1; 382 383 strsep(&cmd, ":"); 384 if (!cmd) { 385 error("missing variable\n"); 386 fastboot_tx_write_str("FAILmissing var"); 387 return; 388 } 389 390 if (!strcmp_l1("version", cmd)) { 391 strncat(response, FASTBOOT_VERSION, chars_left); 392 } else if (!strcmp_l1("bootloader-version", cmd)) { 393 strncat(response, U_BOOT_VERSION, chars_left); 394 } else if (!strcmp_l1("downloadsize", cmd) || 395 !strcmp_l1("max-download-size", cmd)) { 396 char str_num[12]; 397 398 sprintf(str_num, "0x%08x", CONFIG_FASTBOOT_BUF_SIZE); 399 strncat(response, str_num, chars_left); 400 401 /* 402 * This also indicates the start of a new flashing 403 * "session", in which we could have 1-N buffers to 404 * write to a partition. 405 * 406 * Reset our session counter. 407 */ 408 fastboot_flash_session_id = 0; 409 } else if (!strcmp_l1("serialno", cmd)) { 410 s = getenv("serial#"); 411 if (s) 412 strncat(response, s, chars_left); 413 else 414 strcpy(response, "FAILValue not set"); 415 } else { 416 error("unknown variable: %s\n", cmd); 417 strcpy(response, "FAILVariable not implemented"); 418 } 419 fastboot_tx_write_str(response); 420 } 421 422 static unsigned int rx_bytes_expected(unsigned int maxpacket) 423 { 424 int rx_remain = download_size - download_bytes; 425 int rem = 0; 426 if (rx_remain < 0) 427 return 0; 428 if (rx_remain > EP_BUFFER_SIZE) 429 return EP_BUFFER_SIZE; 430 if (rx_remain < maxpacket) { 431 rx_remain = maxpacket; 432 } else if (rx_remain % maxpacket != 0) { 433 rem = rx_remain % maxpacket; 434 rx_remain = rx_remain + (maxpacket - rem); 435 } 436 return rx_remain; 437 } 438 439 #define BYTES_PER_DOT 0x20000 440 static void rx_handler_dl_image(struct usb_ep *ep, struct usb_request *req) 441 { 442 char response[FASTBOOT_RESPONSE_LEN]; 443 unsigned int transfer_size = download_size - download_bytes; 444 const unsigned char *buffer = req->buf; 445 unsigned int buffer_size = req->actual; 446 unsigned int pre_dot_num, now_dot_num; 447 unsigned int max; 448 449 if (req->status != 0) { 450 printf("Bad status: %d\n", req->status); 451 return; 452 } 453 454 if (buffer_size < transfer_size) 455 transfer_size = buffer_size; 456 457 memcpy((void *)CONFIG_FASTBOOT_BUF_ADDR + download_bytes, 458 buffer, transfer_size); 459 460 pre_dot_num = download_bytes / BYTES_PER_DOT; 461 download_bytes += transfer_size; 462 now_dot_num = download_bytes / BYTES_PER_DOT; 463 464 if (pre_dot_num != now_dot_num) { 465 putc('.'); 466 if (!(now_dot_num % 74)) 467 putc('\n'); 468 } 469 470 /* Check if transfer is done */ 471 if (download_bytes >= download_size) { 472 /* 473 * Reset global transfer variable, keep download_bytes because 474 * it will be used in the next possible flashing command 475 */ 476 download_size = 0; 477 req->complete = rx_handler_command; 478 req->length = EP_BUFFER_SIZE; 479 480 strcpy(response, "OKAY"); 481 fastboot_tx_write_str(response); 482 483 printf("\ndownloading of %d bytes finished\n", download_bytes); 484 } else { 485 max = is_high_speed ? hs_ep_out.wMaxPacketSize : 486 fs_ep_out.wMaxPacketSize; 487 req->length = rx_bytes_expected(max); 488 if (req->length < ep->maxpacket) 489 req->length = ep->maxpacket; 490 } 491 492 req->actual = 0; 493 usb_ep_queue(ep, req, 0); 494 } 495 496 static void cb_download(struct usb_ep *ep, struct usb_request *req) 497 { 498 char *cmd = req->buf; 499 char response[FASTBOOT_RESPONSE_LEN]; 500 unsigned int max; 501 502 strsep(&cmd, ":"); 503 download_size = simple_strtoul(cmd, NULL, 16); 504 download_bytes = 0; 505 506 printf("Starting download of %d bytes\n", download_size); 507 508 if (0 == download_size) { 509 strcpy(response, "FAILdata invalid size"); 510 } else if (download_size > CONFIG_FASTBOOT_BUF_SIZE) { 511 download_size = 0; 512 strcpy(response, "FAILdata too large"); 513 } else { 514 sprintf(response, "DATA%08x", download_size); 515 req->complete = rx_handler_dl_image; 516 max = is_high_speed ? hs_ep_out.wMaxPacketSize : 517 fs_ep_out.wMaxPacketSize; 518 req->length = rx_bytes_expected(max); 519 if (req->length < ep->maxpacket) 520 req->length = ep->maxpacket; 521 } 522 fastboot_tx_write_str(response); 523 } 524 525 static void do_bootm_on_complete(struct usb_ep *ep, struct usb_request *req) 526 { 527 char boot_addr_start[12]; 528 char *bootm_args[] = { "bootm", boot_addr_start, NULL }; 529 530 puts("Booting kernel..\n"); 531 532 sprintf(boot_addr_start, "0x%lx", load_addr); 533 do_bootm(NULL, 0, 2, bootm_args); 534 535 /* This only happens if image is somehow faulty so we start over */ 536 do_reset(NULL, 0, 0, NULL); 537 } 538 539 static void cb_boot(struct usb_ep *ep, struct usb_request *req) 540 { 541 fastboot_func->in_req->complete = do_bootm_on_complete; 542 fastboot_tx_write_str("OKAY"); 543 } 544 545 static void do_exit_on_complete(struct usb_ep *ep, struct usb_request *req) 546 { 547 g_dnl_trigger_detach(); 548 } 549 550 static void cb_continue(struct usb_ep *ep, struct usb_request *req) 551 { 552 fastboot_func->in_req->complete = do_exit_on_complete; 553 fastboot_tx_write_str("OKAY"); 554 } 555 556 #ifdef CONFIG_FASTBOOT_FLASH 557 static void cb_flash(struct usb_ep *ep, struct usb_request *req) 558 { 559 char *cmd = req->buf; 560 char response[FASTBOOT_RESPONSE_LEN]; 561 562 strsep(&cmd, ":"); 563 if (!cmd) { 564 error("missing partition name\n"); 565 fastboot_tx_write_str("FAILmissing partition name"); 566 return; 567 } 568 569 strcpy(response, "FAILno flash device defined"); 570 #ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV 571 fb_mmc_flash_write(cmd, fastboot_flash_session_id, 572 (void *)CONFIG_FASTBOOT_BUF_ADDR, 573 download_bytes, response); 574 #endif 575 #ifdef CONFIG_FASTBOOT_FLASH_NAND_DEV 576 fb_nand_flash_write(cmd, fastboot_flash_session_id, 577 (void *)CONFIG_FASTBOOT_BUF_ADDR, 578 download_bytes, response); 579 #endif 580 fastboot_flash_session_id++; 581 fastboot_tx_write_str(response); 582 } 583 #endif 584 585 static void cb_oem(struct usb_ep *ep, struct usb_request *req) 586 { 587 char *cmd = req->buf; 588 #ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV 589 if (strncmp("format", cmd + 4, 6) == 0) { 590 char cmdbuf[32]; 591 sprintf(cmdbuf, "gpt write mmc %x $partitions", 592 CONFIG_FASTBOOT_FLASH_MMC_DEV); 593 if (run_command(cmdbuf, 0)) 594 fastboot_tx_write_str("FAIL"); 595 else 596 fastboot_tx_write_str("OKAY"); 597 } else 598 #endif 599 if (strncmp("unlock", cmd + 4, 8) == 0) { 600 fastboot_tx_write_str("FAILnot implemented"); 601 } 602 else { 603 fastboot_tx_write_str("FAILunknown oem command"); 604 } 605 } 606 607 #ifdef CONFIG_FASTBOOT_FLASH 608 static void cb_erase(struct usb_ep *ep, struct usb_request *req) 609 { 610 char *cmd = req->buf; 611 char response[FASTBOOT_RESPONSE_LEN]; 612 613 strsep(&cmd, ":"); 614 if (!cmd) { 615 error("missing partition name"); 616 fastboot_tx_write_str("FAILmissing partition name"); 617 return; 618 } 619 620 strcpy(response, "FAILno flash device defined"); 621 622 #ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV 623 fb_mmc_erase(cmd, response); 624 #endif 625 #ifdef CONFIG_FASTBOOT_FLASH_NAND_DEV 626 fb_nand_erase(cmd, response); 627 #endif 628 fastboot_tx_write_str(response); 629 } 630 #endif 631 632 struct cmd_dispatch_info { 633 char *cmd; 634 void (*cb)(struct usb_ep *ep, struct usb_request *req); 635 }; 636 637 static const struct cmd_dispatch_info cmd_dispatch_info[] = { 638 { 639 .cmd = "reboot", 640 .cb = cb_reboot, 641 }, { 642 .cmd = "getvar:", 643 .cb = cb_getvar, 644 }, { 645 .cmd = "download:", 646 .cb = cb_download, 647 }, { 648 .cmd = "boot", 649 .cb = cb_boot, 650 }, { 651 .cmd = "continue", 652 .cb = cb_continue, 653 }, 654 #ifdef CONFIG_FASTBOOT_FLASH 655 { 656 .cmd = "flash", 657 .cb = cb_flash, 658 }, { 659 .cmd = "erase", 660 .cb = cb_erase, 661 }, 662 #endif 663 { 664 .cmd = "oem", 665 .cb = cb_oem, 666 }, 667 }; 668 669 static void rx_handler_command(struct usb_ep *ep, struct usb_request *req) 670 { 671 char *cmdbuf = req->buf; 672 void (*func_cb)(struct usb_ep *ep, struct usb_request *req) = NULL; 673 int i; 674 675 if (req->status != 0 || req->length == 0) 676 return; 677 678 for (i = 0; i < ARRAY_SIZE(cmd_dispatch_info); i++) { 679 if (!strcmp_l1(cmd_dispatch_info[i].cmd, cmdbuf)) { 680 func_cb = cmd_dispatch_info[i].cb; 681 break; 682 } 683 } 684 685 if (!func_cb) { 686 error("unknown command: %s\n", cmdbuf); 687 fastboot_tx_write_str("FAILunknown command"); 688 } else { 689 if (req->actual < req->length) { 690 u8 *buf = (u8 *)req->buf; 691 buf[req->actual] = 0; 692 func_cb(ep, req); 693 } else { 694 error("buffer overflow\n"); 695 fastboot_tx_write_str("FAILbuffer overflow"); 696 } 697 } 698 699 *cmdbuf = '\0'; 700 req->actual = 0; 701 usb_ep_queue(ep, req, 0); 702 } 703