arch/ppc/boot/utils/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 (0xc0000000)
  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     printf(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 *inputVmlinux = NULL;
  39     FILE *outputVmlinux = NULL;
  40     unsigned i = 0;
  41     u_int32_t ramFileLen = 0;
  42     u_int32_t ramLen = 0;
  43     u_int32_t roundR = 0;
  44     u_int32_t kernelLen = 0;
  45     u_int32_t actualKernelLen = 0;
  46     u_int32_t round = 0;
  47     u_int32_t roundedKernelLen = 0;
  48     u_int32_t ramStartOffs = 0;
  49     u_int32_t ramPages = 0;
  50     u_int32_t roundedKernelPages = 0;
  51     u_int32_t hvReleaseData = 0;
  52     u_int32_t eyeCatcher = 0xc8a5d9c4;
  53     u_int32_t naca = 0;
  54     u_int32_t xRamDisk = 0;
  55     u_int32_t xRamDiskSize = 0;
  56     if ( argc < 2 ) {
  57         printf("Name of RAM disk file missing.\n");
  58         exit(1);
  59     }
  60
  61     if ( argc < 3 ) {
  62         printf("Name of vmlinux file missing.\n");
  63         exit(1);
  64     }
  65
  66     if ( argc < 4 ) {
  67         printf("Name of vmlinux output file missing.\n");
  68         exit(1);
  69     }
  70
  71     ramDisk = fopen(argv[1], "r");
  72     if ( ! ramDisk ) {
  73         printf("RAM disk file \"%s\" failed to open.\n", argv[1]);
  74         exit(1);
  75     }
  76     inputVmlinux = fopen(argv[2], "r");
  77     if ( ! inputVmlinux ) {
  78         printf("vmlinux file \"%s\" failed to open.\n", argv[2]);
  79         exit(1);
  80     }
  81     outputVmlinux = fopen(argv[3], "w+");
  82     if ( ! outputVmlinux ) {
  83         printf("output vmlinux file \"%s\" failed to open.\n", argv[3]);
  84         exit(1);
  85     }
  86     fseek(ramDisk, 0, SEEK_END);
  87     ramFileLen = ftell(ramDisk);
  88     fseek(ramDisk, 0, SEEK_SET);
  89     printf("%s file size = %d\n", argv[1], ramFileLen);
  90
  91     ramLen = ramFileLen;
  92
  93     roundR = 4096 - (ramLen % 4096);
  94     if ( roundR ) {
  95         printf("Rounding RAM disk file up to a multiple of 4096, adding %d\n", roundR);
  96         ramLen += roundR;
  97     }
  98
  99     printf("Rounded RAM disk size is %d\n", ramLen);
 100     fseek(inputVmlinux, 0, SEEK_END);
 101     kernelLen = ftell(inputVmlinux);
 102     fseek(inputVmlinux, 0, SEEK_SET);
 103     printf("kernel file size = %d\n", kernelLen);
 104     if ( kernelLen == 0 ) {
 105         printf("You must have a linux kernel specified as argv[2]\n");
 106         exit(1);
 107     }
 108
 109     actualKernelLen = kernelLen - ElfHeaderSize;
 110
 111     printf("actual kernel length (minus ELF header) = %d\n", actualKernelLen);
 112
 113     round = actualKernelLen % 4096;
 114     roundedKernelLen = actualKernelLen;
 115     if ( round )
 116         roundedKernelLen += (4096 - round);
 117
 118     printf("actual kernel length rounded up to a 4k multiple = %d\n", roundedKernelLen);
 119
 120     ramStartOffs = roundedKernelLen;
 121     ramPages = ramLen / 4096;
 122
 123     printf("RAM disk pages to copy = %d\n", ramPages);
 124
 125     // Copy 64K ELF header
 126       for (i=0; i<(ElfPages); ++i) {
 127           get4k( inputVmlinux, inbuf );
 128           put4k( outputVmlinux, inbuf );
 129       }
 130
 131     roundedKernelPages = roundedKernelLen / 4096;
 132
 133     fseek(inputVmlinux, ElfHeaderSize, SEEK_SET);
 134
 135     for ( i=0; i<roundedKernelPages; ++i ) {
 136         get4k( inputVmlinux, inbuf );
 137         put4k( outputVmlinux, inbuf );
 138     }
 139
 140     for ( i=0; i<ramPages; ++i ) {
 141         get4k( ramDisk, inbuf );
 142         put4k( outputVmlinux, inbuf );
 143     }
 144
 145     /* Close the input files */
 146     fclose(ramDisk);
 147     fclose(inputVmlinux);
 148     /* And flush the written output file */
 149     fflush(outputVmlinux);
 150
 151     /* fseek to the hvReleaseData pointer */
 152     fseek(outputVmlinux, ElfHeaderSize + 0x24, SEEK_SET);
 153     if (fread(&hvReleaseData, 4, 1, outputVmlinux) != 1) {
 154         death("Could not read hvReleaseData pointer\n", outputVmlinux, argv[3]);
 155     }
 156     hvReleaseData = ntohl(hvReleaseData); /* Convert to native int */
 157     printf("hvReleaseData is at %08x\n", hvReleaseData);
 158
 159     /* fseek to the hvReleaseData */
 160     fseek(outputVmlinux, ElfHeaderSize + hvReleaseData, SEEK_SET);
 161     if (fread(inbuf, 0x40, 1, outputVmlinux) != 1) {
 162         death("Could not read hvReleaseData\n", outputVmlinux, argv[3]);
 163     }
 164     /* Check hvReleaseData sanity */
 165     if (memcmp(inbuf, &eyeCatcher, 4) != 0) {
 166         death("hvReleaseData is invalid\n", outputVmlinux, argv[3]);
 167     }
 168     /* Get the naca pointer */
 169     naca = ntohl(*((u_int32_t *) &inbuf[0x0c])) - KERNELBASE;
 170     printf("naca is at %08x\n", naca);
 171
 172     /* fseek to the naca */
 173     fseek(outputVmlinux, ElfHeaderSize + naca, SEEK_SET);
 174     if (fread(inbuf, 0x18, 1, outputVmlinux) != 1) {
 175         death("Could not read naca\n", outputVmlinux, argv[3]);
 176     }
 177     xRamDisk = ntohl(*((u_int32_t *) &inbuf[0x0c]));
 178     xRamDiskSize = ntohl(*((u_int32_t *) &inbuf[0x14]));
 179     /* Make sure a RAM disk isn't already present */
 180     if ((xRamDisk != 0) || (xRamDiskSize != 0)) {
 181         death("RAM disk is already attached to this kernel\n", outputVmlinux, argv[3]);
 182     }
 183     /* Fill in the values */
 184     *((u_int32_t *) &inbuf[0x0c]) = htonl(ramStartOffs);
 185     *((u_int32_t *) &inbuf[0x14]) = htonl(ramPages);
 186
 187     /* Write out the new naca */
 188     fflush(outputVmlinux);
 189     fseek(outputVmlinux, ElfHeaderSize + naca, SEEK_SET);
 190     if (fwrite(inbuf, 0x18, 1, outputVmlinux) != 1) {
 191         death("Could not write naca\n", outputVmlinux, argv[3]);
 192     }
 193     printf("RAM Disk of 0x%x pages size is attached to the kernel at offset 0x%08x\n",
 194             ramPages, ramStartOffs);
 195
 196     /* Done */
 197     fclose(outputVmlinux);
 198     /* Set permission to executable */
 199     chmod(argv[3], S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH);
 200
 201     return 0;
 202 }
 203