1 /* $NetBSD: ncdcs.c,v 1.1 2009/08/18 20:22:20 skrll Exp $ */ 2 /* 3 ** Program to prepare an ELF file for download to an IBM Network 4 ** Station 300 or 1000 running the NCD firmware. 5 ** 6 ** This may also work for other loaders based on NCD code. 7 ** 8 ** The program expects a signature and some marker fields a couple 9 ** bytes into the image itself, where the checksum gets patched in. 10 ** The checksum itself is a 16bit CRC over the ELF header, the ELF 11 ** program header, and the image portion of the ELF file. The start 12 ** value for the CRC is 0xffff, and no final xor is performed. 13 ** 14 ** Usage: ncdcs <infile> [outfile] 15 ** e.g. ncdcs zImage zImage.ncd 16 ** 17 ** Copyright 2002 Jochen Roth 18 ** NetBSD changes copyright 2003 John Gordon 19 ** 20 ** This program is free software; you can redistribute it and/or 21 ** modify it under the terms of the GNU General Public License, 22 ** Version 2, as published by the Free Software Foundation. 23 ** 24 */ 25 26 27 #include <stdio.h> 28 #include <stdlib.h> 29 #include <string.h> 30 #include <sys/types.h> 31 #include <sys/wait.h> 32 #include <sys/stat.h> 33 #include <unistd.h> 34 #include <fcntl.h> 35 #include <errno.h> 36 37 #ifdef __NetBSD__ 38 39 unsigned short crc16(unsigned short crc, unsigned char *buf, unsigned len); 40 unsigned short get_be_16(unsigned char *p); 41 unsigned long get_be_32(unsigned char *p); 42 void put_be_16(unsigned char *p, unsigned short x); 43 void put_be_32(unsigned char *p, unsigned long x); 44 45 #endif 46 47 static const unsigned short crc16_table[256] = { 48 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf, 49 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7, 50 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e, 51 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876, 52 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd, 53 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5, 54 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c, 55 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974, 56 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb, 57 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3, 58 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a, 59 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72, 60 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9, 61 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1, 62 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738, 63 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70, 64 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7, 65 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff, 66 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036, 67 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e, 68 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5, 69 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd, 70 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134, 71 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c, 72 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3, 73 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb, 74 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232, 75 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a, 76 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1, 77 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9, 78 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330, 79 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78 80 }; 81 82 83 unsigned short crc16(unsigned short crc, unsigned char *buf, unsigned len) 84 { 85 while(len--) { 86 crc = crc16_table[(crc ^ *buf++) & 0xff] ^ (crc >> 8); 87 } 88 return(crc); 89 } 90 91 92 unsigned short get_be_16(unsigned char *p) 93 { 94 unsigned short x = 0; 95 x = (unsigned short)p[0]; 96 x = (x<<8) + (unsigned short)p[1]; 97 return(x); 98 } 99 100 101 unsigned long get_be_32(unsigned char *p) 102 { 103 unsigned long x = 0; 104 x = (unsigned long)p[0]; 105 x = (x<<8) + (unsigned long)p[1]; 106 x = (x<<8) + (unsigned long)p[2]; 107 x = (x<<8) + (unsigned long)p[3]; 108 return(x); 109 } 110 111 112 void put_be_16(unsigned char *p, unsigned short x) 113 { 114 p[0] = (x >> 8); 115 p[1] = x; 116 } 117 118 119 void put_be_32(unsigned char *p, unsigned long x) 120 { 121 p[0] = (x >> 24); 122 p[1] = (x >> 16); 123 p[2] = (x >> 8); 124 p[3] = x; 125 } 126 127 128 int main(int argc, char *argv[]) 129 { 130 char *infile, *outfile; 131 struct stat st; 132 unsigned char *buf, *image, *p; 133 int fd, filesize, old_filesize; 134 unsigned long hdr_len, img_len, img_offset; 135 unsigned short crc, old_crc; 136 137 /* check arguments */ 138 139 if(argc < 2 || argc > 3 || argv[1][0] == '-') { 140 printf("usage: %s <elf-image> [ncd-image]\n", argv[0]); 141 return(1); 142 } 143 144 infile = argv[1]; 145 outfile = argc > 2 ? argv[2] : NULL; 146 147 /* determine file size, allocate buffer, open and read elf file */ 148 149 if ((fd = open(infile, O_RDONLY)) == -1) { 150 perror(infile); 151 return(-1); 152 } 153 154 if (fstat(fd, &st) == -1) { 155 perror(infile); 156 close(fd); 157 return(-1); 158 } 159 buf = malloc(st.st_size + 4); 160 if (buf == NULL) { 161 perror(infile); 162 close(fd); 163 return(-1); 164 } 165 filesize = read(fd, buf, st.st_size); 166 if (filesize != st.st_size) { 167 perror(infile); 168 close(fd); 169 return(-1); 170 } 171 close(fd); 172 173 /* verify elf header */ 174 175 if(memcmp(buf, "\177ELF", 4)) { 176 fprintf(stderr, "%s: not an ELF file\n", infile); 177 return(-1); 178 } 179 if(buf[0x04] != 1 || buf[0x05] != 2 || get_be_16(buf+0x12) != 20) { 180 fprintf(stderr, "%s: not a 32bit big-endian PPC ELF file\n", infile); 181 return(-1); 182 } 183 if(get_be_32(buf+0x1c) != 0x34) { 184 fprintf(stderr, "%s: ELF PPC program header not at expected offset\n", infile); 185 return(-1); 186 } 187 188 if((img_offset = get_be_32(buf+0x38)) != 0x10000) { 189 /* 190 * Doesn't seem to bother the device when the header is less 191 * than 64K, and the default builds for NetBSD always generate 192 * images that are not padded to a 64K boundary... 193 */ 194 #ifndef __NetBSD__ 195 fprintf(stderr, "warning: %s: size of ELF header is not 64k\n", infile); 196 #endif 197 } 198 199 /* verify checksum area markers */ 200 201 image = buf + img_offset; 202 if(memcmp(image + 0x10, "XncdPPC", 8)) { 203 fprintf(stderr, "%s: missing XncdPPC marker\n", infile); 204 return(-1); 205 } 206 207 /* zero out the checksum and size fields, then compute checksum */ 208 209 p = image + 0x18; 210 old_crc = get_be_16(p); 211 old_filesize = get_be_32(p+4); 212 213 memset(p, 0, 8); 214 215 hdr_len = get_be_16(buf+0x28) + get_be_16(buf+0x2a); 216 img_len = get_be_32(buf+0x44); 217 218 crc = 0xffff; 219 crc = crc16(crc, buf, hdr_len); 220 crc = crc16(crc, buf + img_offset, img_len); 221 222 printf("%s: hdr_len=0x%x img_offset=0x%x img_len=0x%x crc=0x%04x fsz=0x%06x\n", infile, (int) hdr_len, (int) img_offset, (int) img_len, crc, filesize); 223 224 if(outfile) { 225 /* patch in the crc and the total file size (???) */ 226 227 put_be_16(p, crc); 228 put_be_32(p+4, filesize); 229 230 if((fd = open(outfile, O_RDWR|O_CREAT|O_TRUNC, st.st_mode)) < 0) { 231 perror(outfile); 232 return(-1); 233 } 234 235 if(write(fd, buf, filesize) != filesize) { 236 perror(outfile); 237 return(-1); 238 } 239 close(fd); 240 } else { 241 /* Check the crc and filesize fields in the file */ 242 243 if((crc == old_crc) && (filesize == old_filesize)) { 244 printf("%s: NCD crc and filesize seem ok.\n", infile); 245 } else { 246 printf("%s: NCD current crc=0x%04x fsz=0x%06x\n", infile, old_crc, old_filesize); 247 } 248 } 249 250 return(0); 251 } 252