LXR linux/arch/powerpc/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#include <elf.h>
   9
  10#define ElfHeaderSize  (64 * 1024)
  11#define ElfPages  (ElfHeaderSize / 4096)
  12#define KERNELBASE (0xc000000000000000)
  13#define _ALIGN_UP(addr,size)    (((addr)+((size)-1))&(~((size)-1)))
  14
  15struct addr_range {
  16        unsigned long long addr;
  17        unsigned long memsize;
  18        unsigned long offset;
  19};
  20
  21static int check_elf64(void *p, int size, struct addr_range *r)
  22{
  23        Elf64_Ehdr *elf64 = p;
  24        Elf64_Phdr *elf64ph;
  25
  26        if (elf64->e_ident[EI_MAG0] != ELFMAG0 ||
  27            elf64->e_ident[EI_MAG1] != ELFMAG1 ||
  28            elf64->e_ident[EI_MAG2] != ELFMAG2 ||
  29            elf64->e_ident[EI_MAG3] != ELFMAG3 ||
  30            elf64->e_ident[EI_CLASS] != ELFCLASS64 ||
  31            elf64->e_ident[EI_DATA] != ELFDATA2MSB ||
  32            elf64->e_type != ET_EXEC || elf64->e_machine != EM_PPC64)
  33                return 0;
  34
  35        if ((elf64->e_phoff + sizeof(Elf64_Phdr)) > size)
  36                return 0;
  37
  38        elf64ph = (Elf64_Phdr *) ((unsigned long)elf64 +
  39                                  (unsigned long)elf64->e_phoff);
  40
  41        r->memsize = (unsigned long)elf64ph->p_memsz;
  42        r->offset = (unsigned long)elf64ph->p_offset;
  43        r->addr = (unsigned long long)elf64ph->p_vaddr;
  44
  45#ifdef DEBUG
  46        printf("PPC64 ELF file, ph:\n");
  47        printf("p_type   0x%08x\n", elf64ph->p_type);
  48        printf("p_flags  0x%08x\n", elf64ph->p_flags);
  49        printf("p_offset 0x%016llx\n", elf64ph->p_offset);
  50        printf("p_vaddr  0x%016llx\n", elf64ph->p_vaddr);
  51        printf("p_paddr  0x%016llx\n", elf64ph->p_paddr);
  52        printf("p_filesz 0x%016llx\n", elf64ph->p_filesz);
  53        printf("p_memsz  0x%016llx\n", elf64ph->p_memsz);
  54        printf("p_align  0x%016llx\n", elf64ph->p_align);
  55        printf("... skipping 0x%08lx bytes of ELF header\n",
  56               (unsigned long)elf64ph->p_offset);
  57#endif
  58
  59        return 64;
  60}
  61static void get4k(FILE *file, char *buf )
  62{
  63        unsigned j;
  64        unsigned num = fread(buf, 1, 4096, file);
  65        for ( j=num; j<4096; ++j )
  66                buf[j] = 0;
  67}
  68
  69static void put4k(FILE *file, char *buf )
  70{
  71        fwrite(buf, 1, 4096, file);
  72}
  73
  74static void death(const char *msg, FILE *fdesc, const char *fname)
  75{
  76        fprintf(stderr, msg);
  77        fclose(fdesc);
  78        unlink(fname);
  79        exit(1);
  80}
  81
  82int main(int argc, char **argv)
  83{
  84        char inbuf[4096];
  85        struct addr_range vmlinux;
  86        FILE *ramDisk;
  87        FILE *inputVmlinux;
  88        FILE *outputVmlinux;
  89
  90        char *rd_name, *lx_name, *out_name;
  91
  92        size_t i;
  93        unsigned long ramFileLen;
  94        unsigned long ramLen;
  95        unsigned long roundR;
  96        unsigned long offset_end;
  97
  98        unsigned long kernelLen;
  99        unsigned long actualKernelLen;
 100        unsigned long round;
 101        unsigned long roundedKernelLen;
 102        unsigned long ramStartOffs;
 103        unsigned long ramPages;
 104        unsigned long roundedKernelPages;
 105        unsigned long hvReleaseData;
 106        u_int32_t eyeCatcher = 0xc8a5d9c4;
 107        unsigned long naca;
 108        unsigned long xRamDisk;
 109        unsigned long xRamDiskSize;
 110        long padPages;
 111  
 112  
 113        if (argc < 2) {
 114                fprintf(stderr, "Name of RAM disk file missing.\n");
 115                exit(1);
 116        }
 117        rd_name = argv[1];
 118
 119        if (argc < 3) {
 120                fprintf(stderr, "Name of vmlinux file missing.\n");
 121                exit(1);
 122        }
 123        lx_name = argv[2];
 124
 125        if (argc < 4) {
 126                fprintf(stderr, "Name of vmlinux output file missing.\n");
 127                exit(1);
 128        }
 129        out_name = argv[3];
 130
 131
 132        ramDisk = fopen(rd_name, "r");
 133        if ( ! ramDisk ) {
 134                fprintf(stderr, "RAM disk file \"%s\" failed to open.\n", rd_name);
 135                exit(1);
 136        }
 137
 138        inputVmlinux = fopen(lx_name, "r");
 139        if ( ! inputVmlinux ) {
 140                fprintf(stderr, "vmlinux file \"%s\" failed to open.\n", lx_name);
 141                exit(1);
 142        }
 143  
 144        outputVmlinux = fopen(out_name, "w+");
 145        if ( ! outputVmlinux ) {
 146                fprintf(stderr, "output vmlinux file \"%s\" failed to open.\n", out_name);
 147                exit(1);
 148        }
 149
 150        i = fread(inbuf, 1, sizeof(inbuf), inputVmlinux);
 151        if (i != sizeof(inbuf)) {
 152                fprintf(stderr, "can not read vmlinux file %s: %u\n", lx_name, i);
 153                exit(1);
 154        }
 155
 156        i = check_elf64(inbuf, sizeof(inbuf), &vmlinux);
 157        if (i == 0) {
 158                fprintf(stderr, "You must have a linux kernel specified as argv[2]\n");
 159                exit(1);
 160        }
 161
 162        /* Input Vmlinux file */
 163        fseek(inputVmlinux, 0, SEEK_END);
 164        kernelLen = ftell(inputVmlinux);
 165        fseek(inputVmlinux, 0, SEEK_SET);
 166        printf("kernel file size = %lu\n", kernelLen);
 167
 168        actualKernelLen = kernelLen - ElfHeaderSize;
 169
 170        printf("actual kernel length (minus ELF header) = %lu\n", actualKernelLen);
 171
 172        round = actualKernelLen % 4096;
 173        roundedKernelLen = actualKernelLen;
 174        if ( round )
 175                roundedKernelLen += (4096 - round);
 176        printf("Vmlinux length rounded up to a 4k multiple = %ld/0x%lx \n", roundedKernelLen, roundedKernelLen);
 177        roundedKernelPages = roundedKernelLen / 4096;
 178        printf("Vmlinux pages to copy = %ld/0x%lx \n", roundedKernelPages, roundedKernelPages);
 179
 180        offset_end = _ALIGN_UP(vmlinux.memsize, 4096);
 181        /* calc how many pages we need to insert between the vmlinux and the start of the ram disk */
 182        padPages = offset_end/4096 - roundedKernelPages;
 183
 184        /* Check and see if the vmlinux is already larger than _end in System.map */
 185        if (padPages < 0) {
 186                /* vmlinux is larger than _end - adjust the offset to the start of the embedded ram disk */ 
 187                offset_end = roundedKernelLen;
 188                printf("vmlinux is larger than _end indicates it needs to be - offset_end = %lx \n", offset_end);
 189                padPages = 0;
 190                printf("will insert %lx pages between the vmlinux and the start of the ram disk \n", padPages);
 191        }
 192        else {
 193                /* _end is larger than vmlinux - use the offset to _end that we calculated from the system map */
 194                printf("vmlinux is smaller than _end indicates is needed - offset_end = %lx \n", offset_end);
 195                printf("will insert %lx pages between the vmlinux and the start of the ram disk \n", padPages);
 196        }
 197
 198
 199
 200        /* Input Ram Disk file */
 201        // Set the offset that the ram disk will be started at.
 202        ramStartOffs = offset_end;  /* determined from the input vmlinux file and the system map */
 203        printf("Ram Disk will start at offset = 0x%lx \n", ramStartOffs);
 204  
 205        fseek(ramDisk, 0, SEEK_END);
 206        ramFileLen = ftell(ramDisk);
 207        fseek(ramDisk, 0, SEEK_SET);
 208        printf("%s file size = %ld/0x%lx \n", rd_name, ramFileLen, ramFileLen);
 209
 210        ramLen = ramFileLen;
 211
 212        roundR = 4096 - (ramLen % 4096);
 213        if ( roundR ) {
 214                printf("Rounding RAM disk file up to a multiple of 4096, adding %ld/0x%lx \n", roundR, roundR);
 215                ramLen += roundR;
 216        }
 217
 218        printf("Rounded RAM disk size is %ld/0x%lx \n", ramLen, ramLen);
 219        ramPages = ramLen / 4096;
 220        printf("RAM disk pages to copy = %ld/0x%lx\n", ramPages, ramPages);
 221
 222
 223
 224  // Copy 64K ELF header
 225        for (i=0; i<(ElfPages); ++i) {
 226                get4k( inputVmlinux, inbuf );
 227                put4k( outputVmlinux, inbuf );
 228        }
 229
 230        /* Copy the vmlinux (as full pages). */
 231        fseek(inputVmlinux, ElfHeaderSize, SEEK_SET);
 232        for ( i=0; i<roundedKernelPages; ++i ) {
 233                get4k( inputVmlinux, inbuf );
 234                put4k( outputVmlinux, inbuf );
 235        }
 236  
 237        /* Insert pad pages (if appropriate) that are needed between */
 238        /* | the end of the vmlinux and the ram disk. */
 239        for (i=0; i<padPages; ++i) {
 240                memset(inbuf, 0, 4096);
 241                put4k(outputVmlinux, inbuf);
 242        }
 243
 244        /* Copy the ram disk (as full pages). */
 245        for ( i=0; i<ramPages; ++i ) {
 246                get4k( ramDisk, inbuf );
 247                put4k( outputVmlinux, inbuf );
 248        }
 249
 250        /* Close the input files */
 251        fclose(ramDisk);
 252        fclose(inputVmlinux);
 253        /* And flush the written output file */
 254        fflush(outputVmlinux);
 255
 256
 257
 258        /* Fixup the new vmlinux to contain the ram disk starting offset (xRamDisk) and the ram disk size (xRamDiskSize) */
 259        /* fseek to the hvReleaseData pointer */
 260        fseek(outputVmlinux, ElfHeaderSize + 0x24, SEEK_SET);
 261        if (fread(&hvReleaseData, 4, 1, outputVmlinux) != 1) {
 262                death("Could not read hvReleaseData pointer\n", outputVmlinux, out_name);
 263        }
 264        hvReleaseData = ntohl(hvReleaseData); /* Convert to native int */
 265        printf("hvReleaseData is at %08lx\n", hvReleaseData);
 266
 267        /* fseek to the hvReleaseData */
 268        fseek(outputVmlinux, ElfHeaderSize + hvReleaseData, SEEK_SET);
 269        if (fread(inbuf, 0x40, 1, outputVmlinux) != 1) {
 270                death("Could not read hvReleaseData\n", outputVmlinux, out_name);
 271        }
 272        /* Check hvReleaseData sanity */
 273        if (memcmp(inbuf, &eyeCatcher, 4) != 0) {
 274                death("hvReleaseData is invalid\n", outputVmlinux, out_name);
 275        }
 276        /* Get the naca pointer */
 277        naca = ntohl(*((u_int32_t*) &inbuf[0x0C])) - KERNELBASE;
 278        printf("Naca is at offset 0x%lx \n", naca);
 279
 280        /* fseek to the naca */
 281        fseek(outputVmlinux, ElfHeaderSize + naca, SEEK_SET);
 282        if (fread(inbuf, 0x18, 1, outputVmlinux) != 1) {
 283                death("Could not read naca\n", outputVmlinux, out_name);
 284        }
 285        xRamDisk = ntohl(*((u_int32_t *) &inbuf[0x0c]));
 286        xRamDiskSize = ntohl(*((u_int32_t *) &inbuf[0x14]));
 287        /* Make sure a RAM disk isn't already present */
 288        if ((xRamDisk != 0) || (xRamDiskSize != 0)) {
 289                death("RAM disk is already attached to this kernel\n", outputVmlinux, out_name);
 290        }
 291        /* Fill in the values */
 292        *((u_int32_t *) &inbuf[0x0c]) = htonl(ramStartOffs);
 293        *((u_int32_t *) &inbuf[0x14]) = htonl(ramPages);
 294
 295        /* Write out the new naca */
 296        fflush(outputVmlinux);
 297        fseek(outputVmlinux, ElfHeaderSize + naca, SEEK_SET);
 298        if (fwrite(inbuf, 0x18, 1, outputVmlinux) != 1) {
 299                death("Could not write naca\n", outputVmlinux, out_name);
 300        }
 301        printf("Ram Disk of 0x%lx pages is attached to the kernel at offset 0x%08lx\n",
 302               ramPages, ramStartOffs);
 303
 304        /* Done */
 305        fclose(outputVmlinux);
 306        /* Set permission to executable */
 307        chmod(out_name, S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH);
 308
 309        return 0;
 310}
 311
 312