tools/mknkboot.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2007 by Dave Chapman
  11  *
  12  * Based on merge0.cpp by James Espinoza, but completely rewritten.
  13  *
  14  * All files in this archive are subject to the GNU General Public License.
  15  * See the file COPYING in the source tree root for full license agreement.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #include <fcntl.h>
  27 #include <unistd.h>
  28 #include <inttypes.h>
  29
  30 /* New entry point for nk.bin - where our dualboot code is inserted */
  31 #define NK_ENTRY_POINT 0x88200000
  32
  33 /* Entry point (and load address) for the main Rockbox bootloader */
  34 #define BL_ENTRY_POINT 0x8a000000
  35
  36 /*
  37
  38 Description of nk.bin from
  39
  40 http://www.xs4all.nl/~itsme/projects/xda/wince-flashfile-formats.html
  41
  42 these files contain most information, several non-contigouos blocks
  43 may be present and an entrypoint in the code.
  44
  45    1. a 7 character signature "B000FF\n" ( that is with 3 zeroes, and
  46       ending in a linefeed )
  47    2. DWORD for image start
  48    3. DWORD for image length
  49    4. followd by several records of this format:
  50          1. DWORD with address where this block is to be flashed to
  51          2. DWORD with the length of this block
  52          3. DWORD with the 32 bit checksum of this block, in perl:
  53             unpack("%32C*", $data);
  54          4. followed by <length> bytes of data
  55    5. the last record has address ZERO, in the length the entrypoint
  56       into the rom, and ZERO as checksum.
  57
  58
  59 NOTE: The Gigabeat-S nk.bin contains 171 records, plus the EOF record.
  60
  61 mknkboot.c appends two images:
  62
  63 1) A "Disable" image which overwrites a word in the EBoot image
  64 2) Our bootloader image, which has the same load address as nk.exe
  65
  66 */
  67
  68 /* win32 compatibility */
  69
  70 #ifndef O_BINARY
  71 #define O_BINARY 0
  72 #endif
  73
  74 #define DISABLE_ADDR    0x88065A10 /* in EBoot */
  75 #define DISABLE_INSN    0xe3a00001
  76 #define DISABLE_SUM     (0xe3+0xa0+0x00+0x01)
  77
  78 /* Code to dual-boot - this is inserted at NK_ENTRY_POINT */
  79 static uint32_t dualboot[] =
  80 {
  81     0xe59f900c,      /* ldr     r9, [pc, #12] -> 0x53fa4000 */
  82     0xe5999000,      /* ldr     r9, [r9] */
  83     0xe3190010,      /* tst     r9, #16 ; 0x10 */
  84 #if 1
  85     /* Branch to Rockbox if hold is on */
  86     0x159ff004,      /* ldrne   pc, [pc, #4]  -> 0x89000000 */
  87 #else
  88     /* Branch to Rockbox if hold is off */
  89     0x059ff004,      /* ldreq   pc, [pc, #4]  -> 0x89000000 */
  90 #endif
  91     /* Branch to original firmware */
  92     0xea0003fa,      /* b 0x1000 */
  93
  94     0x53fa4000,      /* GPIO3_DR */
  95     BL_ENTRY_POINT   /* RB bootloader load address/entry point */
  96 };
  97
  98 static void put_uint32le(uint32_t x, unsigned char* p)
  99 {
 100     p[0] = x & 0xff;
 101     p[1] = (x >> 8) & 0xff;
 102     p[2] = (x >> 16) & 0xff;
 103     p[3] = (x >> 24) & 0xff;
 104 }
 105
 106 static void usage(void)
 107 {
 108     printf("Usage: mknkboot <firmware file> <boot file> <output file>\n");
 109
 110     exit(1);
 111 }
 112
 113 static off_t filesize(int fd) {
 114     struct stat buf;
 115
 116     if (fstat(fd,&buf) < 0) {
 117         perror("[ERR]  Checking filesize of input file");
 118         return -1;
 119     } else {
 120         return(buf.st_size);
 121     }
 122 }
 123
 124
 125 int main(int argc, char *argv[])
 126 {
 127     char *infile, *bootfile, *outfile;
 128     int fdin, fdboot,fdout;
 129     int i,n;
 130     int inlength,bootlength,newlength;
 131     unsigned char* buf;
 132     unsigned char* boot;
 133     unsigned char* boot2;
 134     unsigned char* disable;
 135     uint32_t sum;
 136
 137     if(argc < 3) {
 138         usage();
 139     }
 140
 141     infile = argv[1];
 142     bootfile = argv[2];
 143     outfile = argv[3];
 144
 145     fdin = open(infile, O_RDONLY|O_BINARY);
 146     if (fdin < 0)
 147     {
 148         perror(infile);
 149     }
 150
 151     fdboot = open(bootfile, O_RDONLY|O_BINARY);
 152     if (fdboot < 0)
 153     {
 154         perror(bootfile);
 155     }
 156
 157     inlength = filesize(fdin);
 158
 159     bootlength = filesize(fdboot);
 160
 161     /* Create buffer for original nk.bin, plus our bootloader (with 12
 162        byte header), plus the 16-byte "disable record", plus our dual-boot code */
 163
 164     newlength = inlength + (bootlength + 12) + 16 + (12 + 28);
 165     buf = malloc(newlength);
 166
 167     if (buf==NULL)
 168     {
 169         printf("[ERR]  Could not allocate memory, aborting\n");
 170         return 1;
 171     }
 172
 173     /****** STEP 1 - Read original nk.bin into buffer */
 174
 175     n = read(fdin, buf, inlength);
 176     if (n != inlength)
 177     {
 178         printf("[ERR] Could not read from %s\n",infile);
 179         return 2;
 180     }
 181
 182     /****** STEP 2 - Move EOF record to the new EOF */
 183     memcpy(buf + newlength - 12, buf + inlength - 12, 12);
 184
 185     /* Overwrite default entry point with NK_ENTRY_POINT */
 186     put_uint32le(NK_ENTRY_POINT, buf + newlength - 8);
 187
 188     /****** STEP 3 - Create a record to disable the firmware signature
 189                 check in EBoot */
 190     disable = buf + inlength - 12;
 191
 192     put_uint32le(DISABLE_ADDR, disable);
 193     put_uint32le(4,            disable + 4);
 194     put_uint32le(DISABLE_SUM,  disable + 8);
 195     put_uint32le(DISABLE_INSN, disable + 12);
 196
 197     /****** STEP 4 - Read the bootloader binary */
 198     boot = disable + 16;
 199     n = read(fdboot, boot + 12, bootlength);
 200     if (n != bootlength)
 201     {
 202         printf("[ERR] Could not read from %s\n",bootfile);
 203         return 3;
 204     }
 205
 206     /****** STEP 5 - Create header for bootloader record */
 207
 208     /* Calculate checksum */
 209     sum = 0;
 210     for (i = 0; i < bootlength; i++) {
 211         sum += boot[12 + i];
 212     }
 213
 214     put_uint32le(BL_ENTRY_POINT, boot); /* Our entry point */
 215     put_uint32le(bootlength, boot + 4);
 216     put_uint32le(sum, boot + 8);
 217
 218     /****** STEP 6 -  Insert our dual-boot code */
 219     boot2 = boot + bootlength + 12;
 220
 221     /* Copy dual-boot code in an endian-safe way */
 222     for (i = 0; i < sizeof(dualboot) / 4; i++) {
 223         put_uint32le(dualboot[i], boot2 + 12 + i*4);
 224     }
 225
 226     /* Calculate checksum */
 227     sum = 0;
 228     for (i = 0; i < sizeof(dualboot); i++) {
 229         sum += boot2[i+12];
 230     }
 231
 232     put_uint32le(NK_ENTRY_POINT, boot2); /* New entry point for our nk.bin */
 233     put_uint32le(sizeof(dualboot), boot2 + 4);
 234     put_uint32le(sum, boot2 + 8);
 235
 236     /****** STEP 7 -  Now write the output file */
 237
 238     fdout = open(outfile, O_WRONLY|O_CREAT|O_TRUNC|O_BINARY, 0644);
 239     if (fdout < 0)
 240     {
 241         perror(outfile);
 242     }
 243
 244     n = write(fdout, buf, newlength);
 245     if (n != newlength)
 246     {
 247         printf("[ERR] Could not write output file %s\n",outfile);
 248         return 3;
 249     }
 250
 251     close(fdin);
 252     close(fdboot);
 253     close(fdout);
 254
 255     return 0;
 256 }