int vmspace_init(vmspace_t *vms, uintptr_t addr, uintptr_t sz) {
/* FIXME: Assert starts and finishes on a page boundary! */
range_t r;
r.start = addr;
r.extent = sz;
vms->start = addr;
vms->size = sz;
spinlock_init(&vms->lock);
size_t overhead = round_to_page_size(buddy_calc_overhead(r));
size_t npages = overhead >> get_page_shift();
uintptr_t start = r.start + r.extent - overhead;
int ok = map(start,
alloc_pages(PAGE_REQ_NONE, npages), npages,
PAGE_WRITE);
assert(ok == 0 && "map() failed in vmspace_init!");
r.extent -= overhead;
buddy_init(&vms->allocator, (uint8_t*)start, r, /*start_freed=*/0);
buddy_free_range(&vms->allocator, r);
return 0;
}
int mmap_create(const char* path, off_t size, int flags, mmap_handle_t* mmap_handle) {
int fd = -1;
char* mapped_region;
int oflags;
int prot;
/* round up size to page boundary */
size = round_to_page_size(size);
/* setting open/mmap flags */
prot = PROT_READ | PROT_WRITE;
oflags = O_RDWR | O_CREAT | O_EXCL;
/* opening file */
FAIL_ON((fd = open(path, oflags, S_IRUSR | S_IWUSR)) < 0);
/* set file size by seek and write */
FAIL_ON(lseek(fd, size - 1, SEEK_SET) == (off_t)-1);
FAIL_ON(write(fd, " ", 1) != 1);
/* memory-map the file */
mapped_region = mmap(/* addr = */ NULL, size, prot, flags, fd,
/* offset = */ 0);
FAIL_ON(mapped_region == MAP_FAILED);
/* copy to mmap_handle */
mmap_handle->path = path;
mmap_handle->start_addr = mapped_region;
mmap_handle->size = size;
/* close file descriptor */
(void) close(fd);
return 0;
fail:
if (fd >= 0) (void) close(fd);
return -1;
}