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/* vi: set sw=4 ts=4:
*
* mkswap.c - Format swap device.
*
* Copyright 2009 Rob Landley <rob@landley.net>
*
* Not in SUSv4.
USE_MKSWAP(NEWTOY(mkswap, "<1>1", TOYFLAG_SBIN))
config MKSWAP
bool "mkswap"
default y
help
usage: mkswap DEVICE
Sets up a Linux swap area on a device or file.
*/
#include "toys.h"
void mkswap_main(void)
{
int fd = xopen(*toys.optargs, O_RDWR), pagesize = getpagesize();
off_t len = fdlength(fd);
unsigned int pages = (len/pagesize)-1, *swap = (unsigned int *)toybuf;
// Write header. Note that older kernel versions checked signature
// on disk (not in cache) during swapon, so sync after writing.
swap[0] = 1;
swap[1] = pages;
xlseek(fd, 1024, SEEK_SET);
xwrite(fd, swap, 129*sizeof(unsigned int));
xlseek(fd, pagesize-10, SEEK_SET);
xwrite(fd, "SWAPSPACE2", 10);
fsync(fd);
if (CFG_TOYBOX_FREE) close(fd);
printf("Swapspace size: %luk\n", pages*(unsigned long)(pagesize/1024));
}
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