linux/arch/um/kernel/initrd.c

86 lines
1.7 KiB
C

/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include "linux/init.h"
#include "linux/bootmem.h"
#include "linux/initrd.h"
#include "asm/types.h"
#include "init.h"
#include "os.h"
/* Changed by uml_initrd_setup, which is a setup */
static char *initrd __initdata = NULL;
static int load_initrd(char *filename, void *buf, int size);
static int __init read_initrd(void)
{
void *area;
long long size;
int err;
if (initrd == NULL)
return 0;
err = os_file_size(initrd, &size);
if (err)
return 0;
/*
* This is necessary because alloc_bootmem craps out if you
* ask for no memory.
*/
if (size == 0) {
printk(KERN_ERR "\"%s\" is a zero-size initrd\n", initrd);
return 0;
}
area = alloc_bootmem(size);
if (area == NULL)
return 0;
if (load_initrd(initrd, area, size) == -1)
return 0;
initrd_start = (unsigned long) area;
initrd_end = initrd_start + size;
return 0;
}
__uml_postsetup(read_initrd);
static int __init uml_initrd_setup(char *line, int *add)
{
initrd = line;
return 0;
}
__uml_setup("initrd=", uml_initrd_setup,
"initrd=<initrd image>\n"
" This is used to boot UML from an initrd image. The argument is the\n"
" name of the file containing the image.\n\n"
);
static int load_initrd(char *filename, void *buf, int size)
{
int fd, n;
fd = os_open_file(filename, of_read(OPENFLAGS()), 0);
if (fd < 0) {
printk(KERN_ERR "Opening '%s' failed - err = %d\n", filename,
-fd);
return -1;
}
n = os_read_file(fd, buf, size);
if (n != size) {
printk(KERN_ERR "Read of %d bytes from '%s' failed, "
"err = %d\n", size,
filename, -n);
return -1;
}
os_close_file(fd);
return 0;
}