#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 = %d\n", kernelLen);
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);
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 %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, 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%08x\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;
}
