#include <stdio.h> #include <stdlib.h> #include <netinet/in.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <string.h> #include <elf.h> #define ElfHeaderSize (64 * 1024) #define ElfPages (ElfHeaderSize / 4096) #define KERNELBASE (0xc000000000000000) #define _ALIGN_UP(addr,size) (((addr)+((size)-1))&(~((size)-1))) struct addr_range { unsigned long long addr; unsigned long memsize; unsigned long offset; }; static int check_elf64(void *p, int size, struct addr_range *r) { Elf64_Ehdr *elf64 = p; Elf64_Phdr *elf64ph; if (elf64->e_ident[EI_MAG0] != ELFMAG0 || elf64->e_ident[EI_MAG1] != ELFMAG1 || elf64->e_ident[EI_MAG2] != ELFMAG2 || elf64->e_ident[EI_MAG3] != ELFMAG3 || elf64->e_ident[EI_CLASS] != ELFCLASS64 || elf64->e_ident[EI_DATA] != ELFDATA2MSB || elf64->e_type != ET_EXEC || elf64->e_machine != EM_PPC64) return 0; if ((elf64->e_phoff + sizeof(Elf64_Phdr)) > size) return 0; elf64ph = (Elf64_Phdr *) ((unsigned long)elf64 + (unsigned long)elf64->e_phoff); r->memsize = (unsigned long)elf64ph->p_memsz; r->offset = (unsigned long)elf64ph->p_offset; r->addr = (unsigned long long)elf64ph->p_vaddr; #ifdef DEBUG printf("PPC64 ELF file, ph:\n"); printf("p_type 0x%08x\n", elf64ph->p_type); printf("p_flags 0x%08x\n", elf64ph->p_flags); printf("p_offset 0x%016llx\n", elf64ph->p_offset); printf("p_vaddr 0x%016llx\n", elf64ph->p_vaddr); printf("p_paddr 0x%016llx\n", elf64ph->p_paddr); printf("p_filesz 0x%016llx\n", elf64ph->p_filesz); printf("p_memsz 0x%016llx\n", elf64ph->p_memsz); printf("p_align 0x%016llx\n", elf64ph->p_align); printf("... skipping 0x%08lx bytes of ELF header\n", (unsigned long)elf64ph->p_offset); #endif return 64; } 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]; struct addr_range vmlinux; FILE *ramDisk; FILE *inputVmlinux; FILE *outputVmlinux; char *rd_name, *lx_name, *out_name; size_t i; unsigned long ramFileLen; unsigned long ramLen; unsigned long roundR; unsigned long offset_end; unsigned long kernelLen; unsigned long actualKernelLen; unsigned long round; unsigned long roundedKernelLen; unsigned long ramStartOffs; unsigned long ramPages; unsigned long roundedKernelPages; unsigned long hvReleaseData; u_int32_t eyeCatcher = 0xc8a5d9c4; unsigned long naca; unsigned long xRamDisk; unsigned long xRamDiskSize; long padPages; if (argc < 2) { fprintf(stderr, "Name of RAM disk file missing.\n"); exit(1); } rd_name = argv[1]; if (argc < 3) { fprintf(stderr, "Name of vmlinux file missing.\n"); exit(1); } lx_name = argv[2]; if (argc < 4) { fprintf(stderr, "Name of vmlinux output file missing.\n"); exit(1); } out_name = argv[3]; ramDisk = fopen(rd_name, "r"); if ( ! ramDisk ) { fprintf(stderr, "RAM disk file \"%s\" failed to open.\n", rd_name); exit(1); } inputVmlinux = fopen(lx_name, "r"); if ( ! inputVmlinux ) { fprintf(stderr, "vmlinux file \"%s\" failed to open.\n", lx_name); exit(1); } outputVmlinux = fopen(out_name, "w+"); if ( ! outputVmlinux ) { fprintf(stderr, "output vmlinux file \"%s\" failed to open.\n", out_name); exit(1); } i = fread(inbuf, 1, sizeof(inbuf), inputVmlinux); if (i != sizeof(inbuf)) { fprintf(stderr, "can not read vmlinux file %s: %u\n", lx_name, i); exit(1); } i = check_elf64(inbuf, sizeof(inbuf), &vmlinux); if (i == 0) { fprintf(stderr, "You must have a linux kernel specified as argv[2]\n"); exit(1); } /* Input Vmlinux file */ fseek(inputVmlinux, 0, SEEK_END); kernelLen = ftell(inputVmlinux); fseek(inputVmlinux, 0, SEEK_SET); printf("kernel file size = %lu\n", kernelLen); actualKernelLen = kernelLen - ElfHeaderSize; printf("actual kernel length (minus ELF header) = %lu\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); offset_end = _ALIGN_UP(vmlinux.memsize, 4096); /* 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", rd_name, 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, out_name); } hvReleaseData = ntohl(hvReleaseData); /* Convert to native int */ printf("hvReleaseData is at %08lx\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, out_name); } /* Check hvReleaseData sanity */ if (memcmp(inbuf, &eyeCatcher, 4) != 0) { death("hvReleaseData is invalid\n", outputVmlinux, out_name); } /* 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, out_name); } 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, out_name); } /* 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, out_name); } printf("Ram Disk of 0x%lx pages is attached to the kernel at offset 0x%08lx\n", ramPages, ramStartOffs); /* Done */ fclose(outputVmlinux); /* Set permission to executable */ chmod(out_name, S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH); return 0; }