bootloader/main-pp.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2006 by Barry Wardell
  11  *
  12  * Based on Rockbox iriver bootloader by Linus Nielsen Feltzing
  13  * and the ipodlinux bootloader by Daniel Palffy and Bernard Leach
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License
  17  * as published by the Free Software Foundation; either version 2
  18  * of the License, or (at your option) any later version.
  19  *
  20  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  21  * KIND, either express or implied.
  22  *
  23  ****************************************************************************/
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include "common.h"
  27 #include "cpu.h"
  28 #include "file.h"
  29 #include "system.h"
  30 #include "kernel.h"
  31 #include "lcd.h"
  32 #include "font.h"
  33 #include "ata.h"
  34 #include "adc.h"
  35 #include "button.h"
  36 #include "disk.h"
  37 #include "crc32-mi4.h"
  38 #include <string.h>
  39 #include "power.h"
  40 #if defined(SANSA_E200) || defined(PHILIPS_SA9200)
  41 #include "i2c.h"
  42 #include "backlight-target.h"
  43 #endif
  44 #if defined(SANSA_E200) || defined(SANSA_C200) || defined(PHILIPS_SA9200)
  45 #include "usb.h"
  46 #include "usb_drv.h"
  47 #endif
  48
  49 /* Show the Rockbox logo - in show_logo.c */
  50 extern int show_logo(void);
  51
  52 /* Button definitions */
  53 #if CONFIG_KEYPAD == IRIVER_H10_PAD
  54 #define BOOTLOADER_BOOT_OF      BUTTON_LEFT
  55
  56 #elif CONFIG_KEYPAD == SANSA_E200_PAD
  57 #define BOOTLOADER_BOOT_OF      BUTTON_LEFT
  58
  59 #elif CONFIG_KEYPAD == SANSA_C200_PAD
  60 #define BOOTLOADER_BOOT_OF      BUTTON_LEFT
  61
  62 #elif CONFIG_KEYPAD == MROBE100_PAD
  63 #define BOOTLOADER_BOOT_OF      BUTTON_POWER
  64
  65 #elif CONFIG_KEYPAD == PHILIPS_SA9200_PAD
  66 #define BOOTLOADER_BOOT_OF      BUTTON_VOL_UP
  67
  68 #elif CONFIG_KEYPAD == PHILIPS_HDD1630_PAD
  69 #define BOOTLOADER_BOOT_OF      BUTTON_MENU
  70
  71 #endif
  72
  73 /* Maximum allowed firmware image size. 10MB is more than enough */
  74 #define MAX_LOADSIZE (10*1024*1024)
  75
  76 /* A buffer to load the original firmware or Rockbox into */
  77 unsigned char *loadbuffer = (unsigned char *)DRAM_START;
  78
  79 /* Bootloader version */
  80 char version[] = APPSVERSION;
  81
  82 /* Locations and sizes in hidden partition on Sansa */
  83 #if defined(HAVE_ATA_SD)
  84 #define PPMI_SECTOR_OFFSET  1024
  85 #define PPMI_SECTORS        1
  86 #define MI4_HEADER_SECTORS  1
  87 #define NUM_PARTITIONS      2
  88
  89 #else
  90 #define NUM_PARTITIONS      1
  91
  92 #endif
  93
  94 #define MI4_HEADER_SIZE     0x200
  95
  96 /* mi4 header structure */
  97 struct mi4header_t {
  98     unsigned char magic[4];
  99     uint32_t version;
 100     uint32_t length;
 101     uint32_t crc32;
 102     uint32_t enctype;
 103     uint32_t mi4size;
 104     uint32_t plaintext;
 105     uint32_t dsa_key[10];
 106     uint32_t pad[109];
 107     unsigned char type[4];
 108     unsigned char model[4];
 109 };
 110
 111 /* PPMI header structure */
 112 struct ppmi_header_t {
 113     unsigned char magic[4];
 114     uint32_t length;
 115     uint32_t pad[126];
 116 };
 117
 118 inline unsigned int le2int(unsigned char* buf)
 119 {
 120    int32_t res = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
 121
 122    return res;
 123 }
 124
 125 inline void int2le(unsigned int val, unsigned char* addr)
 126 {
 127     addr[0] = val & 0xFF;
 128     addr[1] = (val >> 8) & 0xff;
 129     addr[2] = (val >> 16) & 0xff;
 130     addr[3] = (val >> 24) & 0xff;
 131 }
 132
 133 struct tea_key {
 134   const char * name;
 135   uint32_t     key[4];
 136 };
 137
 138 #define NUM_KEYS (sizeof(tea_keytable)/sizeof(tea_keytable[0]))
 139 struct tea_key tea_keytable[] = {
 140   { "default" ,          { 0x20d36cc0, 0x10e8c07d, 0xc0e7dcaa, 0x107eb080 } },
 141   { "sansa",             { 0xe494e96e, 0x3ee32966, 0x6f48512b, 0xa93fbb42 } },
 142   { "sansa_gh",          { 0xd7b10538, 0xc662945b, 0x1b3fce68, 0xf389c0e6 } },
 143   { "sansa_103",         { 0x1d29ddc0, 0x2579c2cd, 0xce339e1a, 0x75465dfe } },
 144   { "rhapsody",          { 0x7aa9c8dc, 0xbed0a82a, 0x16204cc7, 0x5904ef38 } },
 145   { "p610",              { 0x950e83dc, 0xec4907f9, 0x023734b9, 0x10cfb7c7 } },
 146   { "p640",              { 0x220c5f23, 0xd04df68e, 0x431b5e25, 0x4dcc1fa1 } },
 147   { "virgin",            { 0xe83c29a1, 0x04862973, 0xa9b3f0d4, 0x38be2a9c } },
 148   { "20gc_eng",          { 0x0240772c, 0x6f3329b5, 0x3ec9a6c5, 0xb0c9e493 } },
 149   { "20gc_fre",          { 0xbede8817, 0xb23bfe4f, 0x80aa682d, 0xd13f598c } },
 150   { "elio_p722",         { 0x6af3b9f8, 0x777483f5, 0xae8181cc, 0xfa6d8a84 } },
 151   { "c200",              { 0xbf2d06fa, 0xf0e23d59, 0x29738132, 0xe2d04ca7 } },
 152   { "c200_103",          { 0x2a7968de, 0x15127979, 0x142e60a7, 0xe49c1893 } },
 153   { "c200_106",          { 0xa913d139, 0xf842f398, 0x3e03f1a6, 0x060ee012 } },
 154   { "view",              { 0x70e19bda, 0x0c69ea7d, 0x2b8b1ad1, 0xe9767ced } },
 155   { "sa9200",            { 0x33ea0236, 0x9247bdc5, 0xdfaedf9f, 0xd67c9d30 } },
 156   { "hdd1630",           { 0x04543ced, 0xcebfdbad, 0xf7477872, 0x0d12342e } },
 157 };
 158
 159 /*
 160
 161 tea_decrypt() from http://en.wikipedia.org/wiki/Tiny_Encryption_Algorithm
 162
 163 "Following is an adaptation of the reference encryption and decryption
 164 routines in C, released into the public domain by David Wheeler and
 165 Roger Needham:"
 166
 167 */
 168
 169 /* NOTE: The mi4 version of TEA uses a different initial value to sum compared
 170          to the reference implementation and the main loop is 8 iterations, not
 171          32.
 172 */
 173
 174 static void tea_decrypt(uint32_t* v0, uint32_t* v1, uint32_t* k) {
 175     uint32_t sum=0xF1BBCDC8, i;                    /* set up */
 176     uint32_t delta=0x9E3779B9;                     /* a key schedule constant */
 177     uint32_t k0=k[0], k1=k[1], k2=k[2], k3=k[3];   /* cache key */
 178     for(i=0; i<8; i++) {                               /* basic cycle start */
 179         *v1 -= ((*v0<<4) + k2) ^ (*v0 + sum) ^ ((*v0>>5) + k3);
 180         *v0 -= ((*v1<<4) + k0) ^ (*v1 + sum) ^ ((*v1>>5) + k1);
 181         sum -= delta;                                   /* end cycle */
 182     }
 183 }
 184
 185 /* mi4 files are encrypted in 64-bit blocks (two little-endian 32-bit
 186    integers) and the key is incremented after each block
 187  */
 188
 189 static void tea_decrypt_buf(unsigned char* src, unsigned char* dest, size_t n, uint32_t * key)
 190 {
 191     uint32_t v0, v1;
 192     unsigned int i;
 193
 194     for (i = 0; i < (n / 8); i++) {
 195         v0 = le2int(src);
 196         v1 = le2int(src+4);
 197
 198         tea_decrypt(&v0, &v1, key);
 199
 200         int2le(v0, dest);
 201         int2le(v1, dest+4);
 202
 203         src += 8;
 204         dest += 8;
 205
 206         /* Now increment the key */
 207         key[0]++;
 208         if (key[0]==0) {
 209             key[1]++;
 210             if (key[1]==0) {
 211                 key[2]++;
 212                 if (key[2]==0) {
 213                     key[3]++;
 214                 }
 215             }
 216         }
 217     }
 218 }
 219
 220 static inline bool tea_test_key(unsigned char magic_enc[8], uint32_t * key, int unaligned)
 221 {
 222     unsigned char magic_dec[8];
 223     tea_decrypt_buf(magic_enc, magic_dec, 8, key);
 224
 225     return (le2int(&magic_dec[4*unaligned]) == 0xaa55aa55);
 226 }
 227
 228 static int tea_find_key(struct mi4header_t *mi4header, int fd)
 229 {
 230     unsigned int i;
 231     int rc;
 232     unsigned int j;
 233     uint32_t key[4];
 234     unsigned char magic_enc[8];
 235     int key_found = -1;
 236     unsigned int magic_location = mi4header->length-4;
 237     int unaligned = 0;
 238
 239     if ( (magic_location % 8) != 0 )
 240     {
 241         unaligned = 1;
 242         magic_location -= 4;
 243     }
 244
 245     /* Load encrypted magic 0xaa55aa55 to check key */
 246     lseek(fd, MI4_HEADER_SIZE + magic_location, SEEK_SET);
 247     rc = read(fd, magic_enc, 8);
 248     if(rc < 8 )
 249         return EREAD_IMAGE_FAILED;
 250
 251     printf("Searching for key:");
 252
 253     for (i=0; i < NUM_KEYS && (key_found<0) ; i++) {
 254         key[0] = tea_keytable[i].key[0];
 255         key[1] = tea_keytable[i].key[1];
 256         key[2] = tea_keytable[i].key[2];
 257         key[3] = tea_keytable[i].key[3];
 258
 259         /* Now increment the key */
 260         for(j=0; j<((magic_location-mi4header->plaintext)/8); j++){
 261             key[0]++;
 262             if (key[0]==0) {
 263                 key[1]++;
 264                 if (key[1]==0) {
 265                     key[2]++;
 266                     if (key[2]==0) {
 267                         key[3]++;
 268                     }
 269                 }
 270             }
 271         }
 272
 273         if (tea_test_key(magic_enc,key,unaligned))
 274         {
 275             key_found = i;
 276             printf("%s...found", tea_keytable[i].name);
 277         } else {
 278            /* printf("%s...failed", tea_keytable[i].name); */
 279         }
 280     }
 281
 282     return key_found;
 283 }
 284
 285
 286 /* Load mi4 format firmware image */
 287 int load_mi4(unsigned char* buf, char* firmware, unsigned int buffer_size)
 288 {
 289     int fd;
 290     struct mi4header_t mi4header;
 291     int rc;
 292     unsigned long sum;
 293     char filename[MAX_PATH];
 294
 295     snprintf(filename,sizeof(filename),"/.rockbox/%s",firmware);
 296     fd = open(filename, O_RDONLY);
 297     if(fd < 0)
 298     {
 299         snprintf(filename,sizeof(filename),"/%s",firmware);
 300         fd = open(filename, O_RDONLY);
 301         if(fd < 0)
 302             return EFILE_NOT_FOUND;
 303     }
 304
 305     read(fd, &mi4header, MI4_HEADER_SIZE);
 306
 307     /* MI4 file size */
 308     printf("mi4 size: %x", mi4header.mi4size);
 309
 310     if ((mi4header.mi4size-MI4_HEADER_SIZE) > buffer_size)
 311         return EFILE_TOO_BIG;
 312
 313     /* CRC32 */
 314     printf("CRC32: %x", mi4header.crc32);
 315
 316     /* Rockbox model id */
 317     printf("Model id: %.4s", mi4header.model);
 318
 319     /* Read binary type (RBOS, RBBL) */
 320     printf("Binary type: %.4s", mi4header.type);
 321
 322     /* Load firmware file */
 323     lseek(fd, MI4_HEADER_SIZE, SEEK_SET);
 324     rc = read(fd, buf, mi4header.mi4size-MI4_HEADER_SIZE);
 325     if(rc < (int)mi4header.mi4size-MI4_HEADER_SIZE)
 326         return EREAD_IMAGE_FAILED;
 327
 328     /* Check CRC32 to see if we have a valid file */
 329     sum = chksum_crc32 (buf, mi4header.mi4size - MI4_HEADER_SIZE);
 330
 331     printf("Calculated CRC32: %x", sum);
 332
 333     if(sum != mi4header.crc32)
 334         return EBAD_CHKSUM;
 335
 336     if( (mi4header.plaintext + MI4_HEADER_SIZE) != mi4header.mi4size)
 337     {
 338         /* Load encrypted firmware */
 339         int key_index = tea_find_key(&mi4header, fd);
 340
 341         if (key_index < 0)
 342             return EINVALID_FORMAT;
 343
 344         /* Plaintext part is already loaded */
 345         buf += mi4header.plaintext;
 346
 347         /* Decrypt in-place */
 348         tea_decrypt_buf(buf, buf,
 349                         mi4header.mi4size-(mi4header.plaintext+MI4_HEADER_SIZE),
 350                         tea_keytable[key_index].key);
 351
 352         printf("%s key used", tea_keytable[key_index].name);
 353
 354         /* Check decryption was successfull */
 355         if(le2int(&buf[mi4header.length-mi4header.plaintext-4]) != 0xaa55aa55)
 356         {
 357             return EREAD_IMAGE_FAILED;
 358         }
 359     }
 360
 361     return EOK;
 362 }
 363
 364 #if defined(HAVE_ATA_SD)
 365 /* Load mi4 firmware from a hidden disk partition */
 366 int load_mi4_part(unsigned char* buf, struct partinfo* pinfo,
 367                   unsigned int buffer_size, bool disable_rebuild)
 368 {
 369     struct mi4header_t mi4header;
 370     struct ppmi_header_t ppmi_header;
 371     unsigned long sum;
 372
 373     /* Read header to find out how long the mi4 file is. */
 374     ata_read_sectors(IF_MV2(0,) pinfo->start + PPMI_SECTOR_OFFSET,
 375                             PPMI_SECTORS, &ppmi_header);
 376
 377     /* The first four characters at 0x80000 (sector 1024) should be PPMI*/
 378     if( memcmp(ppmi_header.magic, "PPMI", 4) )
 379         return EFILE_NOT_FOUND;
 380
 381     printf("BL mi4 size: %x", ppmi_header.length);
 382
 383     /* Read mi4 header of the OF */
 384     ata_read_sectors(IF_MV2(0,) pinfo->start + PPMI_SECTOR_OFFSET + PPMI_SECTORS
 385                        + (ppmi_header.length/512), MI4_HEADER_SECTORS, &mi4header);
 386
 387     /* We don't support encrypted mi4 files yet */
 388     if( (mi4header.plaintext) != (mi4header.mi4size-MI4_HEADER_SIZE))
 389         return EINVALID_FORMAT;
 390
 391     /* MI4 file size */
 392     printf("OF mi4 size: %x", mi4header.mi4size);
 393
 394     if ((mi4header.mi4size-MI4_HEADER_SIZE) > buffer_size)
 395         return EFILE_TOO_BIG;
 396
 397     /* CRC32 */
 398     printf("CRC32: %x", mi4header.crc32);
 399
 400     /* Rockbox model id */
 401     printf("Model id: %.4s", mi4header.model);
 402
 403     /* Read binary type (RBOS, RBBL) */
 404     printf("Binary type: %.4s", mi4header.type);
 405
 406     /* Load firmware */
 407     ata_read_sectors(IF_MV2(0,) pinfo->start + PPMI_SECTOR_OFFSET + PPMI_SECTORS
 408                         + (ppmi_header.length/512) + MI4_HEADER_SECTORS,
 409                         (mi4header.mi4size-MI4_HEADER_SIZE)/512, buf);
 410
 411     /* Check CRC32 to see if we have a valid file */
 412     sum = chksum_crc32 (buf,mi4header.mi4size-MI4_HEADER_SIZE);
 413
 414     printf("Calculated CRC32: %x", sum);
 415
 416     if(sum != mi4header.crc32)
 417         return EBAD_CHKSUM;
 418
 419 #ifdef SANSA_E200
 420     if (disable_rebuild)
 421     {
 422         char block[512];
 423
 424         printf("Disabling database rebuild");
 425
 426         ata_read_sectors(IF_MV2(0,) pinfo->start + 0x3c08, 1, block);
 427         block[0xe1] = 0;
 428         ata_write_sectors(IF_MV2(0,) pinfo->start + 0x3c08, 1, block);
 429     }
 430 #else
 431     (void) disable_rebuild;
 432 #endif
 433
 434     return EOK;
 435 }
 436 #endif
 437
 438 void* main(void)
 439 {
 440     int i;
 441     int btn;
 442     int rc;
 443     int num_partitions;
 444     struct partinfo* pinfo;
 445 #if defined(SANSA_E200) || defined(SANSA_C200) || defined(PHILIPS_SA9200)
 446     int usb_retry = 0;
 447     bool usb = false;
 448 #else
 449     char buf[256];
 450     unsigned short* identify_info;
 451 #endif
 452
 453     chksum_crc32gentab ();
 454
 455     system_init();
 456     kernel_init();
 457
 458     lcd_init();
 459
 460     font_init();
 461     show_logo();
 462
 463     adc_init();
 464     button_init();
 465 #if defined(SANSA_E200) || defined(PHILIPS_SA9200)
 466     i2c_init();
 467     _backlight_on();
 468 #endif
 469
 470     if (button_hold())
 471     {
 472         verbose = true;
 473         lcd_clear_display();
 474         printf("Hold switch on");
 475         printf("Shutting down...");
 476         sleep(HZ);
 477         power_off();
 478     }
 479
 480     btn = button_read_device();
 481
 482     /* Enable bootloader messages if any button is pressed */
 483     if (btn) {
 484         lcd_clear_display();
 485         verbose = true;
 486     }
 487
 488 #if defined(SANSA_E200) || defined(SANSA_C200) || defined(PHILIPS_SA9200)
 489 #if !defined(USE_ROCKBOX_USB)
 490     usb_init();
 491     while (usb_drv_powered() && usb_retry < 5 && !usb)
 492     {
 493         usb_retry++;
 494         sleep(HZ/4);
 495         usb = (usb_detect() == USB_INSERTED);
 496     }
 497     if (usb)
 498         btn |= BOOTLOADER_BOOT_OF;
 499 #endif /* USE_ROCKBOX_USB */
 500 #endif
 501
 502     lcd_setfont(FONT_SYSFIXED);
 503
 504     printf("Rockbox boot loader");
 505     printf("Version: %s", version);
 506     printf(MODEL_NAME);
 507
 508     i=ata_init();
 509 #if !defined(HAVE_ATA_SD)
 510     if (i==0) {
 511         identify_info=ata_get_identify();
 512         /* Show model */
 513         for (i=0; i < 20; i++) {
 514             ((unsigned short*)buf)[i]=htobe16(identify_info[i+27]);
 515         }
 516         buf[40]=0;
 517         for (i=39; i && buf[i]==' '; i--) {
 518             buf[i]=0;
 519         }
 520         printf(buf);
 521     } else {
 522         error(EATA, i);
 523     }
 524 #endif
 525
 526     disk_init(IF_MV(0));
 527     num_partitions = disk_mount_all();
 528     if (num_partitions<=0)
 529     {
 530         error(EDISK,num_partitions);
 531     }
 532
 533     /* Just list the first 2 partitions since we don't have any devices yet
 534        that have more than that */
 535     for(i=0; i<NUM_PARTITIONS; i++)
 536     {
 537         pinfo = disk_partinfo(i);
 538         printf("Partition %d: 0x%02x %ld MB",
 539                 i, pinfo->type, pinfo->size / 2048);
 540     }
 541
 542     if(btn & BOOTLOADER_BOOT_OF)
 543     {
 544         /* Load original mi4 firmware in to a memory buffer called loadbuffer.
 545            The rest of the loading is done in crt0.S.
 546            1) First try reading from the hidden partition (on Sansa only).
 547            2) Next try a decrypted mi4 file in /System/OF.mi4
 548            3) Finally, try a raw firmware binary in /System/OF.mi4. It should be
 549               a mi4 firmware decrypted and header stripped using mi4code.
 550         */
 551         printf("Loading original firmware...");
 552
 553 #if defined(HAVE_ATA_SD)
 554         /* First try a (hidden) firmware partition */
 555         printf("Trying firmware partition");
 556         pinfo = disk_partinfo(1);
 557         if(pinfo->type == PARTITION_TYPE_OS2_HIDDEN_C_DRIVE)
 558         {
 559             rc = load_mi4_part(loadbuffer, pinfo, MAX_LOADSIZE, usb);
 560             if (rc < EOK) {
 561                 printf("Can't load from partition");
 562                 printf(strerror(rc));
 563             } else {
 564                 return (void*)loadbuffer;
 565             }
 566         } else {
 567             printf("No hidden partition found.");
 568         }
 569 #endif
 570
 571         printf("Trying /System/OF.mi4");
 572         rc=load_mi4(loadbuffer, "/System/OF.mi4", MAX_LOADSIZE);
 573         if (rc < EOK) {
 574             printf("Can't load /System/OF.mi4");
 575             printf(strerror(rc));
 576         } else {
 577             return (void*)loadbuffer;
 578         }
 579
 580         printf("Trying /System/OF.bin");
 581         rc=load_raw_firmware(loadbuffer, "/System/OF.bin", MAX_LOADSIZE);
 582         if (rc < EOK) {
 583             printf("Can't load /System/OF.bin");
 584             printf(strerror(rc));
 585         } else {
 586             return (void*)loadbuffer;
 587         }
 588
 589         error(0, 0);
 590
 591     } else {
 592 #if 0 /* e200: enable to be able to dump the hidden partition */
 593         if(btn & BUTTON_UP)
 594         {
 595             int fd;
 596             pinfo = disk_partinfo(1);
 597             fd = open("/part.bin", O_CREAT|O_RDWR);
 598             char sector[512];
 599             for(i=0; i<40960; i++){
 600                 if (!(i%100))
 601                 {
 602                     printf("dumping sector %d", i);
 603                 }
 604                 ata_read_sectors(IF_MV2(0,) pinfo->start + i, 1, sector);
 605                 write(fd,sector,512);
 606             }
 607             close(fd);
 608         }
 609 #endif
 610         printf("Loading Rockbox...");
 611         rc=load_mi4(loadbuffer, BOOTFILE, MAX_LOADSIZE);
 612         if (rc < EOK) {
 613             printf("Can't load %s:", BOOTFILE);
 614             printf(strerror(rc));
 615
 616 #ifdef OLD_BOOTFILE
 617             /* Try loading rockbox from old rockbox.e200/rockbox.h10 format */
 618             rc=load_firmware(loadbuffer, OLD_BOOTFILE, MAX_LOADSIZE);
 619             if (rc < EOK) {
 620                 printf("Can't load %s:", OLD_BOOTFILE);
 621                 error(EBOOTFILE, rc);
 622             }
 623 #endif
 624         }
 625     }
 626
 627     return (void*)loadbuffer;
 628 }
 629
 630 #if !defined(SANSA_E200) && !defined(SANSA_C200) && !defined(PHILIPS_SA9200)
 631 /* These functions are present in the firmware library, but we reimplement
 632    them here because the originals do a lot more than we want */
 633 void usb_acknowledge(void)
 634 {
 635 }
 636
 637 void usb_wait_for_disconnect(void)
 638 {
 639 }
 640 #endif
 641