arch/ppc64/boot/addRamDisk.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <netinet/in.h>
   4 #include <unistd.h>
   5 #include <sys/types.h>
   6 #include <sys/stat.h>
   7 #include <string.h>
   8
   9 #define ElfHeaderSize  (64 * 1024)
  10 #define ElfPages  (ElfHeaderSize / 4096)
  11 #define KERNELBASE (0xc000000000000000)
  12
  13 void get4k(FILE *file, char *buf )
  14 {
  15         unsigned j;
  16         unsigned num = fread(buf, 1, 4096, file);
  17         for ( j=num; j<4096; ++j )
  18                 buf[j] = 0;
  19 }
  20
  21 void put4k(FILE *file, char *buf )
  22 {
  23         fwrite(buf, 1, 4096, file);
  24 }
  25
  26 void death(const char *msg, FILE *fdesc, const char *fname)
  27 {
  28         fprintf(stderr, msg);
  29         fclose(fdesc);
  30         unlink(fname);
  31         exit(1);
  32 }
  33
  34 int main(int argc, char **argv)
  35 {
  36         char inbuf[4096];
  37         FILE *ramDisk = NULL;
  38         FILE *sysmap = NULL;
  39         FILE *inputVmlinux = NULL;
  40         FILE *outputVmlinux = NULL;
  41
  42         unsigned i = 0;
  43         unsigned long ramFileLen = 0;
  44         unsigned long ramLen = 0;
  45         unsigned long roundR = 0;
  46
  47         unsigned long sysmapFileLen = 0;
  48         unsigned long sysmapLen = 0;
  49         unsigned long sysmapPages = 0;
  50         char* ptr_end = NULL;
  51         unsigned long offset_end = 0;
  52
  53         unsigned long kernelLen = 0;
  54         unsigned long actualKernelLen = 0;
  55         unsigned long round = 0;
  56         unsigned long roundedKernelLen = 0;
  57         unsigned long ramStartOffs = 0;
  58         unsigned long ramPages = 0;
  59         unsigned long roundedKernelPages = 0;
  60         unsigned long hvReleaseData = 0;
  61         u_int32_t eyeCatcher = 0xc8a5d9c4;
  62         unsigned long naca = 0;
  63         unsigned long xRamDisk = 0;
  64         unsigned long xRamDiskSize = 0;
  65         long padPages = 0;
  66
  67
  68         if (argc < 2) {
  69                 fprintf(stderr, "Name of RAM disk file missing.\n");
  70                 exit(1);
  71         }
  72
  73         if (argc < 3) {
  74                 fprintf(stderr, "Name of System Map input file is missing.\n");
  75                 exit(1);
  76         }
  77
  78         if (argc < 4) {
  79                 fprintf(stderr, "Name of vmlinux file missing.\n");
  80                 exit(1);
  81         }
  82
  83         if (argc < 5) {
  84                 fprintf(stderr, "Name of vmlinux output file missing.\n");
  85                 exit(1);
  86         }
  87
  88
  89         ramDisk = fopen(argv[1], "r");
  90         if ( ! ramDisk ) {
  91                 fprintf(stderr, "RAM disk file \"%s\" failed to open.\n", argv[1]);
  92                 exit(1);
  93         }
  94
  95         sysmap = fopen(argv[2], "r");
  96         if ( ! sysmap ) {
  97                 fprintf(stderr, "System Map file \"%s\" failed to open.\n", argv[2]);
  98                 exit(1);
  99         }
 100
 101         inputVmlinux = fopen(argv[3], "r");
 102         if ( ! inputVmlinux ) {
 103                 fprintf(stderr, "vmlinux file \"%s\" failed to open.\n", argv[3]);
 104                 exit(1);
 105         }
 106
 107         outputVmlinux = fopen(argv[4], "w+");
 108         if ( ! outputVmlinux ) {
 109                 fprintf(stderr, "output vmlinux file \"%s\" failed to open.\n", argv[4]);
 110                 exit(1);
 111         }
 112
 113
 114
 115         /* Input Vmlinux file */
 116         fseek(inputVmlinux, 0, SEEK_END);
 117         kernelLen = ftell(inputVmlinux);
 118         fseek(inputVmlinux, 0, SEEK_SET);
 119         printf("kernel file size = %d\n", kernelLen);
 120         if ( kernelLen == 0 ) {
 121                 fprintf(stderr, "You must have a linux kernel specified as argv[3]\n");
 122                 exit(1);
 123         }
 124
 125         actualKernelLen = kernelLen - ElfHeaderSize;
 126
 127         printf("actual kernel length (minus ELF header) = %d\n", actualKernelLen);
 128
 129         round = actualKernelLen % 4096;
 130         roundedKernelLen = actualKernelLen;
 131         if ( round )
 132                 roundedKernelLen += (4096 - round);
 133         printf("Vmlinux length rounded up to a 4k multiple = %ld/0x%lx \n", roundedKernelLen, roundedKernelLen);
 134         roundedKernelPages = roundedKernelLen / 4096;
 135         printf("Vmlinux pages to copy = %ld/0x%lx \n", roundedKernelPages, roundedKernelPages);
 136
 137
 138
 139         /* Input System Map file */
 140         /* (needs to be processed simply to determine if we need to add pad pages due to the static variables not being included in the vmlinux) */
 141         fseek(sysmap, 0, SEEK_END);
 142         sysmapFileLen = ftell(sysmap);
 143         fseek(sysmap, 0, SEEK_SET);
 144         printf("%s file size = %ld/0x%lx \n", argv[2], sysmapFileLen, sysmapFileLen);
 145
 146         sysmapLen = sysmapFileLen;
 147
 148         roundR = 4096 - (sysmapLen % 4096);
 149         if (roundR) {
 150                 printf("Rounding System Map file up to a multiple of 4096, adding %ld/0x%lx \n", roundR, roundR);
 151                 sysmapLen += roundR;
 152         }
 153         printf("Rounded System Map size is %ld/0x%lx \n", sysmapLen, sysmapLen);
 154
 155         /* Process the Sysmap file to determine where _end is */
 156         sysmapPages = sysmapLen / 4096;
 157         /* read the whole file line by line, expect that it doesn't fail */
 158         while ( fgets(inbuf, 4096, sysmap) )  ;
 159         /* search for _end in the last page of the system map */
 160         ptr_end = strstr(inbuf, " _end");
 161         if (!ptr_end) {
 162                 fprintf(stderr, "Unable to find _end in the sysmap file \n");
 163                 fprintf(stderr, "inbuf: \n");
 164                 fprintf(stderr, "%s \n", inbuf);
 165                 exit(1);
 166         }
 167         printf("Found _end in the last page of the sysmap - backing up 10 characters it looks like %s", ptr_end-10);
 168         /* convert address of _end in system map to hex offset. */
 169         offset_end = (unsigned int)strtol(ptr_end-10, NULL, 16);
 170         /* calc how many pages we need to insert between the vmlinux and the start of the ram disk */
 171         padPages = offset_end/4096 - roundedKernelPages;
 172
 173         /* Check and see if the vmlinux is already larger than _end in System.map */
 174         if (padPages < 0) {
 175                 /* vmlinux is larger than _end - adjust the offset to the start of the embedded ram disk */
 176                 offset_end = roundedKernelLen;
 177                 printf("vmlinux is larger than _end indicates it needs to be - offset_end = %lx \n", offset_end);
 178                 padPages = 0;
 179                 printf("will insert %lx pages between the vmlinux and the start of the ram disk \n", padPages);
 180         }
 181         else {
 182                 /* _end is larger than vmlinux - use the offset to _end that we calculated from the system map */
 183                 printf("vmlinux is smaller than _end indicates is needed - offset_end = %lx \n", offset_end);
 184                 printf("will insert %lx pages between the vmlinux and the start of the ram disk \n", padPages);
 185         }
 186
 187
 188
 189         /* Input Ram Disk file */
 190         // Set the offset that the ram disk will be started at.
 191         ramStartOffs = offset_end;  /* determined from the input vmlinux file and the system map */
 192         printf("Ram Disk will start at offset = 0x%lx \n", ramStartOffs);
 193
 194         fseek(ramDisk, 0, SEEK_END);
 195         ramFileLen = ftell(ramDisk);
 196         fseek(ramDisk, 0, SEEK_SET);
 197         printf("%s file size = %ld/0x%lx \n", argv[1], ramFileLen, ramFileLen);
 198
 199         ramLen = ramFileLen;
 200
 201         roundR = 4096 - (ramLen % 4096);
 202         if ( roundR ) {
 203                 printf("Rounding RAM disk file up to a multiple of 4096, adding %ld/0x%lx \n", roundR, roundR);
 204                 ramLen += roundR;
 205         }
 206
 207         printf("Rounded RAM disk size is %ld/0x%lx \n", ramLen, ramLen);
 208         ramPages = ramLen / 4096;
 209         printf("RAM disk pages to copy = %ld/0x%lx\n", ramPages, ramPages);
 210
 211
 212
 213   // Copy 64K ELF header
 214         for (i=0; i<(ElfPages); ++i) {
 215                 get4k( inputVmlinux, inbuf );
 216                 put4k( outputVmlinux, inbuf );
 217         }
 218
 219         /* Copy the vmlinux (as full pages). */
 220         fseek(inputVmlinux, ElfHeaderSize, SEEK_SET);
 221         for ( i=0; i<roundedKernelPages; ++i ) {
 222                 get4k( inputVmlinux, inbuf );
 223                 put4k( outputVmlinux, inbuf );
 224         }
 225
 226         /* Insert pad pages (if appropriate) that are needed between */
 227         /* | the end of the vmlinux and the ram disk. */
 228         for (i=0; i<padPages; ++i) {
 229                 memset(inbuf, 0, 4096);
 230                 put4k(outputVmlinux, inbuf);
 231         }
 232
 233         /* Copy the ram disk (as full pages). */
 234         for ( i=0; i<ramPages; ++i ) {
 235                 get4k( ramDisk, inbuf );
 236                 put4k( outputVmlinux, inbuf );
 237         }
 238
 239         /* Close the input files */
 240         fclose(ramDisk);
 241         fclose(inputVmlinux);
 242         /* And flush the written output file */
 243         fflush(outputVmlinux);
 244
 245
 246
 247         /* Fixup the new vmlinux to contain the ram disk starting offset (xRamDisk) and the ram disk size (xRamDiskSize) */
 248         /* fseek to the hvReleaseData pointer */
 249         fseek(outputVmlinux, ElfHeaderSize + 0x24, SEEK_SET);
 250         if (fread(&hvReleaseData, 4, 1, outputVmlinux) != 1) {
 251                 death("Could not read hvReleaseData pointer\n", outputVmlinux, argv[4]);
 252         }
 253         hvReleaseData = ntohl(hvReleaseData); /* Convert to native int */
 254         printf("hvReleaseData is at %08x\n", hvReleaseData);
 255
 256         /* fseek to the hvReleaseData */
 257         fseek(outputVmlinux, ElfHeaderSize + hvReleaseData, SEEK_SET);
 258         if (fread(inbuf, 0x40, 1, outputVmlinux) != 1) {
 259                 death("Could not read hvReleaseData\n", outputVmlinux, argv[4]);
 260         }
 261         /* Check hvReleaseData sanity */
 262         if (memcmp(inbuf, &eyeCatcher, 4) != 0) {
 263                 death("hvReleaseData is invalid\n", outputVmlinux, argv[4]);
 264         }
 265         /* Get the naca pointer */
 266         naca = ntohl(*((u_int32_t*) &inbuf[0x0C])) - KERNELBASE;
 267         printf("Naca is at offset 0x%lx \n", naca);
 268
 269         /* fseek to the naca */
 270         fseek(outputVmlinux, ElfHeaderSize + naca, SEEK_SET);
 271         if (fread(inbuf, 0x18, 1, outputVmlinux) != 1) {
 272                 death("Could not read naca\n", outputVmlinux, argv[4]);
 273         }
 274         xRamDisk = ntohl(*((u_int32_t *) &inbuf[0x0c]));
 275         xRamDiskSize = ntohl(*((u_int32_t *) &inbuf[0x14]));
 276         /* Make sure a RAM disk isn't already present */
 277         if ((xRamDisk != 0) || (xRamDiskSize != 0)) {
 278                 death("RAM disk is already attached to this kernel\n", outputVmlinux, argv[4]);
 279         }
 280         /* Fill in the values */
 281         *((u_int32_t *) &inbuf[0x0c]) = htonl(ramStartOffs);
 282         *((u_int32_t *) &inbuf[0x14]) = htonl(ramPages);
 283
 284         /* Write out the new naca */
 285         fflush(outputVmlinux);
 286         fseek(outputVmlinux, ElfHeaderSize + naca, SEEK_SET);
 287         if (fwrite(inbuf, 0x18, 1, outputVmlinux) != 1) {
 288                 death("Could not write naca\n", outputVmlinux, argv[4]);
 289         }
 290         printf("Ram Disk of 0x%lx pages is attached to the kernel at offset 0x%08x\n",
 291                ramPages, ramStartOffs);
 292
 293         /* Done */
 294         fclose(outputVmlinux);
 295         /* Set permission to executable */
 296         chmod(argv[4], S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH);
 297
 298         return 0;
 299 }
 300