1 /* mkswap.c - Format swap device. 2 * 3 * Copyright 2009 Rob Landley <rob (at) landley.net> 4 5 USE_MKSWAP(NEWTOY(mkswap, "<1>1", TOYFLAG_SBIN)) 6 7 config MKSWAP 8 bool "mkswap" 9 default y 10 help 11 usage: mkswap DEVICE 12 13 Sets up a Linux swap area on a device or file. 14 */ 15 16 #include "toys.h" 17 18 void mkswap_main(void) 19 { 20 int fd = xopen(*toys.optargs, O_RDWR), pagesize = sysconf(_SC_PAGE_SIZE); 21 off_t len = fdlength(fd); 22 unsigned int pages = (len/pagesize)-1, *swap = (unsigned int *)toybuf; 23 24 // Write header. Note that older kernel versions checked signature 25 // on disk (not in cache) during swapon, so sync after writing. 26 27 swap[0] = 1; 28 swap[1] = pages; 29 xlseek(fd, 1024, SEEK_SET); 30 xwrite(fd, swap, 129*sizeof(unsigned int)); 31 xlseek(fd, pagesize-10, SEEK_SET); 32 xwrite(fd, "SWAPSPACE2", 10); 33 fsync(fd); 34 35 if (CFG_TOYBOX_FREE) close(fd); 36 37 printf("Swapspace size: %luk\n", pages*(unsigned long)(pagesize/1024)); 38 } 39
