source: mainline/boot/tools/ia64/vmaxlma.c@ 8ccd2ea

/*
 * Swap VMA and LMA in ELF header.
 *
 *  by Jakub Jermar <jermar@itbs.cz>
 *
 *  GPL'ed, copyleft
 */

/*
 * HP's IA-64 simulator Ski seems to confuse VMA and LMA in the ELF header.
 * Instead of using LMA, Ski loads sections at their VMA addresses.
 * This short program provides a workaround for this bug by simply
 * swapping VMA and LMA in the ELF header of the executable.
 *
 * Note that after applying this workaround, you will be able to load
 * ELF objects with different VMA and LMA in Ski, but the executable
 * will become wronged for other potential uses.
 */
 
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>

void syntax(char *prg)
{
        printf("%s ELF-file\n", prg);
        exit(1);
}

void error(char *msg)
{
        printf("Error: %s\n", msg);
        exit(2);
}

#define ELF_VMA (0x50/sizeof(unsigned long long))
#define ELF_LMA (0x58/sizeof(unsigned long long))
#define ELF_ENTRY (0x18/sizeof(unsigned long long))

#define LENGTH  0x98

int main(int argc, char *argv[])
{
        int fd;
        unsigned long long vma, lma,entry;
        unsigned long long *elf;

        if (argc != 2)
                syntax(argv[0]);
        
        fd = open(argv[1], O_RDWR);
        if (fd == -1)
                error("open failed");

        elf = mmap(NULL, LENGTH, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
        if ((void *) elf  == (void *) -1)
                error("map failed");
                
        lma = elf[ELF_LMA];
        elf[ELF_VMA] = lma;
        entry = lma;
        elf[ELF_ENTRY] = entry;
        
        if (munmap(elf, LENGTH) == -1)
                error("munmap failed");
        
        if (close(fd) == -1)
                error("close failed");
                
        return 0;
}