void __init setup_physmem(unsigned long start, unsigned long reserve_end,
unsigned long len, unsigned long long highmem)
{
unsigned long reserve = reserve_end - start;
int pfn = PFN_UP(__pa(reserve_end));
int delta = (len - reserve) >> PAGE_SHIFT;
int err, offset, bootmap_size;
physmem_fd = create_mem_file(len + highmem);
offset = uml_reserved - uml_physmem;
err = os_map_memory((void *) uml_reserved, physmem_fd, offset,
len - offset, 1, 1, 1);
if (err < 0) {
printf("setup_physmem - mapping %ld bytes of memory at 0x%p "
"failed - errno = %d\n", len - offset,
(void *) uml_reserved, err);
exit(1);
}
/*
* Special kludge - This page will be mapped in to userspace processes
* from physmem_fd, so it needs to be written out there.
*/
os_seek_file(physmem_fd, __pa(&__syscall_stub_start));
os_write_file(physmem_fd, &__syscall_stub_start, PAGE_SIZE);
bootmap_size = init_bootmem(pfn, pfn + delta);
free_bootmem(__pa(reserve_end) + bootmap_size,
len - bootmap_size - reserve);
}
int __init can_drop_memory(void)
{
void *addr;
int fd, ok = 0;
printk("Checking host MADV_REMOVE support...");
fd = create_mem_file(UM_KERN_PAGE_SIZE);
if(fd < 0){
printk("Creating test memory file failed, err = %d\n", -fd);
goto out;
}
addr = mmap64(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
MAP_SHARED, fd, 0);
if(addr == MAP_FAILED){
printk("Mapping test memory file failed, err = %d\n", -errno);
goto out_close;
}
if(madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0){
printk("MADV_REMOVE failed, err = %d\n", -errno);
goto out_unmap;
}
printk("OK\n");
ok = 1;
out_unmap:
munmap(addr, UM_KERN_PAGE_SIZE);
out_close:
close(fd);
out:
return ok;
}
void remap_data(void *segment_start, void *segment_end, int w)
{
void *addr;
unsigned long size;
int data, prot;
if(w) prot = PROT_WRITE;
else prot = 0;
prot |= PROT_READ | PROT_EXEC;
size = (unsigned long) segment_end -
(unsigned long) segment_start;
data = create_mem_file(size);
addr = mmap(NULL, size, PROT_WRITE | PROT_READ, MAP_SHARED, data, 0);
if(addr == MAP_FAILED){
perror("mapping new data segment");
exit(1);
}
memcpy(addr, segment_start, size);
if(switcheroo(data, prot, addr, segment_start, size) < 0){
printf("switcheroo failed\n");
exit(1);
}
}
int
main (int argc, char* argv[])
{
int fd, kernel_fd = -1;
/* scanning whether there's -h or --help in the options */
char c, *unit;
while ((c = getopt_long(argc, argv, ":skmdx:", longopts, 0)) != -1) {
switch (c) {
case 'h':
printf (" -d <path>, --disk=<path> specify normal disk\n"
" -k <path>, --kernel=<path> specify kernel file\n"
" -m NUM , --memsize=NUM specify memory size\n"
" -s <path>, --swap=<path> specify swap disk\n"
" -h, --help print this message and exit\n");
return 0;
break;
case 'k':
if ((kernel_fd = open (optarg, O_RDONLY)) < 0)
return 1;
break;
case 'm':
memsize = strtol (optarg, &unit, 10);
if (*unit == 'K' || *unit == 'k')
memsize <<= 10;
else if (*unit == 'M' || *unit == 'm')
memsize <<= 20;
break;
default:
/* ignore other options now */
break;
}
}
if (kernel_fd < 0) {
printf ("No kernel file specified.\n");
return 1;
}
struct stat buf;
fstat (kernel_fd, &buf);
fd = create_mem_file (memsize);
/* map the temp file & copy boot and kernel code to the memory */
int brk_end = (int)sbrk (0);
mmap ((void*)brk_end, memsize, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_SHARED, fd, 0);
read_kernel (kernel_fd, brk_end - KERNBASE);
/* map the reserved part to where it really should be */
mmap ((void*)KERNBASE, RESERVED_SIZE, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_SHARED, fd, 0);
/* Now we have access to ginfo normally. */
ginfo->mem_fd = fd;
e820_init (kernel_fd);
parse_opts (argc, argv);
/* unmap useless page table entries */
memcpy ((void*)(BOOT_CODE), (void*)&__boot_start, PGSIZE);
stk_init (brk_end, fd);
void (*boot_start) (void);
boot_start = __pa (__boot_entry);
boot_start ();
return 0;
}