void
mminit(char *file, int mode)
{
Dir *d;
uintptr va;
void *p, *np;
int hashsize; /* make it a power of two -- see why later */
ventifd = open(file, mode);
if (ventifd < 0)
sysfatal("Can't open %s: %r\n", file);
d = dirfstat(ventifd);
if (! d)
sysfatal("Can't stat %s: %r", file);
/* allocate: size for the file, 1/32 that size for the map, and
* start it at the 1 GB boundary, please.
*/
/* get top of heap */
p = segbrk(0, 0);
va = (uintptr)p;
/* no non-nix systems we just usr sbrk and only have little pages */
hashsize = d->length/32;
maxmap = hashsize / sizeof(*maps);
hashb = log2(maxmap);
if (va == (uintptr)-1) {
p = sbrk(0);
va = (uintptr)p;
maps = (void *)va;
va += hashsize;
mmventidatabase = mmventidata = (void *)va;
va += d->length;
va = ROUNDUP((va), 4096);
if (brk((void *)va) < 0)
sysfatal("brk to %#p failed\n", (void *)va);
} else {
va = ROUNDUP((va), 1ULL*GiB);
maps = (void *)va;
va += hashsize;
mmventidatabase = mmventidata = (void *)va;
va += d->length;
va = ROUNDUP((va), 1ULL*GiB);
segbrk(0, (void *)va);
}
fprint(2, "mmventidatabase is %#p\n", mmventidatabase);
fprint(2, "File size %lld, hashsize %d, maps %#p, data %#p\n", d->length,
hashsize, maps, mmventidata);
/* morecore */
np=(void*)va;
segbrk(p, np);
reload();
}
void
main(void)
{
char *p = segbrk((void *)(1024ULL * 1024 * 1024 * 1024), nil);
print("%p\n", p);
memset(p, 0, 4096);
}
