49 lines
1.1 KiB
C
49 lines
1.1 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/* mkswap.c - format swap device (Linux v1 only)
|
|
*
|
|
* Copyright 2006 Rob Landley <rob@landley.net>
|
|
*
|
|
* Licensed under GPL version 2, see file LICENSE in this tarball for details.
|
|
*/
|
|
|
|
#include "libbb.h"
|
|
|
|
int mkswap_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
|
int mkswap_main(int argc, char **argv)
|
|
{
|
|
int fd, pagesize;
|
|
off_t len;
|
|
unsigned int hdr[129];
|
|
|
|
// No options supported.
|
|
|
|
if (argc != 2) bb_show_usage();
|
|
|
|
// Figure out how big the device is and announce our intentions.
|
|
|
|
fd = xopen(argv[1], O_RDWR);
|
|
len = fdlength(fd);
|
|
pagesize = getpagesize();
|
|
printf("Setting up swapspace version 1, size = %"OFF_FMT"d bytes\n",
|
|
len - pagesize);
|
|
|
|
// Make a header.
|
|
|
|
memset(hdr, 0, sizeof(hdr));
|
|
hdr[0] = 1;
|
|
hdr[1] = (len / pagesize) - 1;
|
|
|
|
// Write the header. Sync to disk because some kernel versions check
|
|
// signature on disk (not in cache) during swapon.
|
|
|
|
xlseek(fd, 1024, SEEK_SET);
|
|
xwrite(fd, hdr, sizeof(hdr));
|
|
xlseek(fd, pagesize-10, SEEK_SET);
|
|
xwrite(fd, "SWAPSPACE2", 10);
|
|
fsync(fd);
|
|
|
|
if (ENABLE_FEATURE_CLEAN_UP) close(fd);
|
|
|
|
return 0;
|
|
}
|