minix/commands/ramdisk/ramdisk.c
Ben Gras ed1af3c86c VM: full munmap
complete munmap implementation; single-page references made
a general munmap() implementation possible to write cleanly.

	. memory: let the MIOCRAMSIZE ioctl set the imgrd device
	  size (but only to 0)
	. let the ramdisk command set sizes to 0
	. use this command to set /dev/imgrd to 0 after mounting /usr
	  in /etc/rc, so the boot time ramdisk is freed (about 4MB
	  currently)
2012-09-18 13:17:52 +02:00

46 lines
697 B
C

#include <paths.h>
#include <sys/ioc_memory.h>
#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
int
main(int argc, char *argv[])
{
int fd;
signed long size;
char *d;
if(argc < 2 || argc > 3) {
fprintf(stderr, "usage: %s <size in kB> [device]\n",
argv[0]);
return 1;
}
d = argc == 2 ? _PATH_RAMDISK : argv[2];
if((fd=open(d, O_RDONLY)) < 0) {
perror(d);
return 1;
}
#define KFACTOR 1024
size = atol(argv[1])*KFACTOR;
if(size < 0) {
fprintf(stderr, "size should be non-negative.\n");
return 1;
}
if(ioctl(fd, MIOCRAMSIZE, &size) < 0) {
perror("MIOCRAMSIZE");
return 1;
}
fprintf(stderr, "size on %s set to %dkB\n", d, size/KFACTOR);
return 0;
}