scripts/mod/mk_elfconfig.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <stdio.h>
0003 #include <stdlib.h>
0004 #include <string.h>
0005 #include <elf.h>
0006
0007 int
0008 main(int argc, char **argv)
0009 {
0010     unsigned char ei[EI_NIDENT];
0011     union { short s; char c[2]; } endian_test;
0012
0013     if (fread(ei, 1, EI_NIDENT, stdin) != EI_NIDENT) {
0014         fprintf(stderr, "Error: input truncated\n");
0015         return 1;
0016     }
0017     if (memcmp(ei, ELFMAG, SELFMAG) != 0) {
0018         fprintf(stderr, "Error: not ELF\n");
0019         return 1;
0020     }
0021     switch (ei[EI_CLASS]) {
0022     case ELFCLASS32:
0023         printf("#define KERNEL_ELFCLASS ELFCLASS32\n");
0024         break;
0025     case ELFCLASS64:
0026         printf("#define KERNEL_ELFCLASS ELFCLASS64\n");
0027         break;
0028     default:
0029         exit(1);
0030     }
0031     switch (ei[EI_DATA]) {
0032     case ELFDATA2LSB:
0033         printf("#define KERNEL_ELFDATA ELFDATA2LSB\n");
0034         break;
0035     case ELFDATA2MSB:
0036         printf("#define KERNEL_ELFDATA ELFDATA2MSB\n");
0037         break;
0038     default:
0039         exit(1);
0040     }
0041
0042     if (sizeof(unsigned long) == 4) {
0043         printf("#define HOST_ELFCLASS ELFCLASS32\n");
0044     } else if (sizeof(unsigned long) == 8) {
0045         printf("#define HOST_ELFCLASS ELFCLASS64\n");
0046     }
0047
0048     endian_test.s = 0x0102;
0049     if (memcmp(endian_test.c, "\x01\x02", 2) == 0)
0050         printf("#define HOST_ELFDATA ELFDATA2MSB\n");
0051     else if (memcmp(endian_test.c, "\x02\x01", 2) == 0)
0052         printf("#define HOST_ELFDATA ELFDATA2LSB\n");
0053     else
0054         exit(1);
0055
0056     return 0;
0057 }