#include <stdio.h> #include <stdlib.h> #include <netinet/in.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <string.h> #define ElfHeaderSize (64 * 1024) #define ElfPages (ElfHeaderSize / 4096) #define KERNELBASE (0xc000000000000000) void get4k(FILE *file, char *buf ) { unsigned j; unsigned num = fread(buf, 1, 4096, file); for ( j=num; j<4096; ++j ) buf[j] = 0; } void put4k(FILE *file, char *buf ) { fwrite(buf, 1, 4096, file); } void death(const char *msg, FILE *fdesc, const char *fname) { fprintf(stderr, msg); fclose(fdesc); unlink(fname); exit(1); } int main(int argc, char **argv) { char inbuf[4096]; FILE *ramDisk = NULL; FILE *sysmap = NULL; FILE *inputVmlinux = NULL; FILE *outputVmlinux = NULL; unsigned i = 0; unsigned long ramFileLen = 0; unsigned long ramLen = 0; unsigned long roundR = 0; unsigned long sysmapFileLen = 0; unsigned long sysmapLen = 0; unsigned long sysmapPages = 0; char* ptr_end = NULL; unsigned long offset_end = 0; unsigned long kernelLen = 0; unsigned long actualKernelLen = 0; unsigned long round = 0; unsigned long roundedKernelLen = 0; unsigned long ramStartOffs = 0; unsigned long ramPages = 0; unsigned long roundedKernelPages = 0; unsigned long hvReleaseData = 0; u_int32_t eyeCatcher = 0xc8a5d9c4; unsigned long naca = 0; unsigned long xRamDisk = 0; unsigned long xRamDiskSize = 0; long padPages = 0; if (argc < 2) { fprintf(stderr, "Name of RAM disk file missing.\n"); exit(1); } if (argc < 3) { fprintf(stderr, "Name of System Map input file is missing.\n"); exit(1); } if (argc < 4) { fprintf(stderr, "Name of vmlinux file missing.\n"); exit(1); } if (argc < 5) { fprintf(stderr, "Name of vmlinux output file missing.\n"); exit(1); } ramDisk = fopen(argv[1], "r"); if ( ! ramDisk ) { fprintf(stderr, "RAM disk file \"%s\" failed to open.\n", argv[1]); exit(1); } sysmap = fopen(argv[2], "r"); if ( ! sysmap ) { fprintf(stderr, "System Map file \"%s\" failed to open.\n", argv[2]); exit(1); } inputVmlinux = fopen(argv[3], "r"); if ( ! inputVmlinux ) { fprintf(stderr, "vmlinux file \"%s\" failed to open.\n", argv[3]); exit(1); } outputVmlinux = fopen(argv[4], "w+"); if ( ! outputVmlinux ) { fprintf(stderr, "output vmlinux file \"%s\" failed to open.\n", argv[4]); exit(1); } /* Input Vmlinux file */ fseek(inputVmlinux, 0, SEEK_END); kernelLen = ftell(inputVmlinux); fseek(inputVmlinux, 0, SEEK_SET); printf("kernel file size = %d\n", kernelLen); if ( kernelLen == 0 ) { fprintf(stderr, "You must have a linux kernel specified as argv[3]\n"); exit(1); } actualKernelLen = kernelLen - ElfHeaderSize; printf("actual kernel length (minus ELF header) = %d\n", actualKernelLen); round = actualKernelLen % 4096; roundedKernelLen = actualKernelLen; if ( round ) roundedKernelLen += (4096 - round); printf("Vmlinux length rounded up to a 4k multiple = %ld/0x%lx \n", roundedKernelLen, roundedKernelLen); roundedKernelPages = roundedKernelLen / 4096; printf("Vmlinux pages to copy = %ld/0x%lx \n", roundedKernelPages, roundedKernelPages); /* Input System Map file */ /* (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) */ fseek(sysmap, 0, SEEK_END); sysmapFileLen = ftell(sysmap); fseek(sysmap, 0, SEEK_SET); printf("%s file size = %ld/0x%lx \n", argv[2], sysmapFileLen, sysmapFileLen); sysmapLen = sysmapFileLen; roundR = 4096 - (sysmapLen % 4096); if (roundR) { printf("Rounding System Map file up to a multiple of 4096, adding %ld/0x%lx \n", roundR, roundR); sysmapLen += roundR; } printf("Rounded System Map size is %ld/0x%lx \n", sysmapLen, sysmapLen); /* Process the Sysmap file to determine where _end is */ sysmapPages = sysmapLen / 4096; /* read the whole file line by line, expect that it doesn't fail */ while ( fgets(inbuf, 4096, sysmap) ) ; /* search for _end in the last page of the system map */ ptr_end = strstr(inbuf, " _end"); if (!ptr_end) { fprintf(stderr, "Unable to find _end in the sysmap file \n"); fprintf(stderr, "inbuf: \n"); fprintf(stderr, "%s \n", inbuf); exit(1); } printf("Found _end in the last page of the sysmap - backing up 10 characters it looks like %s", ptr_end-10); /* convert address of _end in system map to hex offset. */ offset_end = (unsigned int)strtol(ptr_end-10, NULL, 16); /* calc how many pages we need to insert between the vmlinux and the start of the ram disk */ padPages = offset_end/4096 - roundedKernelPages; /* Check and see if the vmlinux is already larger than _end in System.map */ if (padPages < 0) { /* vmlinux is larger than _end - adjust the offset to the start of the embedded ram disk */ offset_end = roundedKernelLen; printf("vmlinux is larger than _end indicates it needs to be - offset_end = %lx \n", offset_end); padPages = 0; printf("will insert %lx pages between the vmlinux and the start of the ram disk \n", padPages); } else { /* _end is larger than vmlinux - use the offset to _end that we calculated from the system map */ printf("vmlinux is smaller than _end indicates is needed - offset_end = %lx \n", offset_end); printf("will insert %lx pages between the vmlinux and the start of the ram disk \n", padPages); } /* Input Ram Disk file */ // Set the offset that the ram disk will be started at. ramStartOffs = offset_end; /* determined from the input vmlinux file and the system map */ printf("Ram Disk will start at offset = 0x%lx \n", ramStartOffs); fseek(ramDisk, 0, SEEK_END); ramFileLen = ftell(ramDisk); fseek(ramDisk, 0, SEEK_SET); printf("%s file size = %ld/0x%lx \n", argv[1], ramFileLen, ramFileLen); ramLen = ramFileLen; roundR = 4096 - (ramLen % 4096); if ( roundR ) { printf("Rounding RAM disk file up to a multiple of 4096, adding %ld/0x%lx \n", roundR, roundR); ramLen += roundR; } printf("Rounded RAM disk size is %ld/0x%lx \n", ramLen, ramLen); ramPages = ramLen / 4096; printf("RAM disk pages to copy = %ld/0x%lx\n", ramPages, ramPages); // Copy 64K ELF header for (i=0; i<(ElfPages); ++i) { get4k( inputVmlinux, inbuf ); put4k( outputVmlinux, inbuf ); } /* Copy the vmlinux (as full pages). */ fseek(inputVmlinux, ElfHeaderSize, SEEK_SET); for ( i=0; i<roundedKernelPages; ++i ) { get4k( inputVmlinux, inbuf ); put4k( outputVmlinux, inbuf ); } /* Insert pad pages (if appropriate) that are needed between */ /* | the end of the vmlinux and the ram disk. */ for (i=0; i<padPages; ++i) { memset(inbuf, 0, 4096); put4k(outputVmlinux, inbuf); } /* Copy the ram disk (as full pages). */ for ( i=0; i<ramPages; ++i ) { get4k( ramDisk, inbuf ); put4k( outputVmlinux, inbuf ); } /* Close the input files */ fclose(ramDisk); fclose(inputVmlinux); /* And flush the written output file */ fflush(outputVmlinux); /* Fixup the new vmlinux to contain the ram disk starting offset (xRamDisk) and the ram disk size (xRamDiskSize) */ /* fseek to the hvReleaseData pointer */ fseek(outputVmlinux, ElfHeaderSize + 0x24, SEEK_SET); if (fread(&hvReleaseData, 4, 1, outputVmlinux) != 1) { death("Could not read hvReleaseData pointer\n", outputVmlinux, argv[4]); } hvReleaseData = ntohl(hvReleaseData); /* Convert to native int */ printf("hvReleaseData is at %08x\n", hvReleaseData); /* fseek to the hvReleaseData */ fseek(outputVmlinux, ElfHeaderSize + hvReleaseData, SEEK_SET); if (fread(inbuf, 0x40, 1, outputVmlinux) != 1) { death("Could not read hvReleaseData\n", outputVmlinux, argv[4]); } /* Check hvReleaseData sanity */ if (memcmp(inbuf, &eyeCatcher, 4) != 0) { death("hvReleaseData is invalid\n", outputVmlinux, argv[4]); } /* Get the naca pointer */ naca = ntohl(*((u_int32_t*) &inbuf[0x0C])) - KERNELBASE; printf("Naca is at offset 0x%lx \n", naca); /* fseek to the naca */ fseek(outputVmlinux, ElfHeaderSize + naca, SEEK_SET); if (fread(inbuf, 0x18, 1, outputVmlinux) != 1) { death("Could not read naca\n", outputVmlinux, argv[4]); } xRamDisk = ntohl(*((u_int32_t *) &inbuf[0x0c])); xRamDiskSize = ntohl(*((u_int32_t *) &inbuf[0x14])); /* Make sure a RAM disk isn't already present */ if ((xRamDisk != 0) || (xRamDiskSize != 0)) { death("RAM disk is already attached to this kernel\n", outputVmlinux, argv[4]); } /* Fill in the values */ *((u_int32_t *) &inbuf[0x0c]) = htonl(ramStartOffs); *((u_int32_t *) &inbuf[0x14]) = htonl(ramPages); /* Write out the new naca */ fflush(outputVmlinux); fseek(outputVmlinux, ElfHeaderSize + naca, SEEK_SET); if (fwrite(inbuf, 0x18, 1, outputVmlinux) != 1) { death("Could not write naca\n", outputVmlinux, argv[4]); } printf("Ram Disk of 0x%lx pages is attached to the kernel at offset 0x%08x\n", ramPages, ramStartOffs); /* Done */ fclose(outputVmlinux); /* Set permission to executable */ chmod(argv[4], S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH); return 0; }