xref: /openbmc/linux/arch/um/kernel/initrd.c (revision 64c70b1c)
1 /*
2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5 
6 #include "linux/init.h"
7 #include "linux/bootmem.h"
8 #include "linux/initrd.h"
9 #include "asm/types.h"
10 #include "kern_util.h"
11 #include "initrd.h"
12 #include "init.h"
13 #include "os.h"
14 
15 /* Changed by uml_initrd_setup, which is a setup */
16 static char *initrd __initdata = NULL;
17 
18 static int __init read_initrd(void)
19 {
20 	void *area;
21 	long long size;
22 	int err;
23 
24 	if(initrd == NULL)
25 		return 0;
26 
27 	err = os_file_size(initrd, &size);
28 	if(err)
29 		return 0;
30 
31 	area = alloc_bootmem(size);
32 	if(area == NULL)
33 		return 0;
34 
35 	if(load_initrd(initrd, area, size) == -1)
36 		return 0;
37 
38 	initrd_start = (unsigned long) area;
39 	initrd_end = initrd_start + size;
40 	return 0;
41 }
42 
43 __uml_postsetup(read_initrd);
44 
45 static int __init uml_initrd_setup(char *line, int *add)
46 {
47 	initrd = line;
48 	return 0;
49 }
50 
51 __uml_setup("initrd=", uml_initrd_setup,
52 "initrd=<initrd image>\n"
53 "    This is used to boot UML from an initrd image.  The argument is the\n"
54 "    name of the file containing the image.\n\n"
55 );
56 
57 int load_initrd(char *filename, void *buf, int size)
58 {
59 	int fd, n;
60 
61 	fd = os_open_file(filename, of_read(OPENFLAGS()), 0);
62 	if(fd < 0){
63 		printk("Opening '%s' failed - err = %d\n", filename, -fd);
64 		return -1;
65 	}
66 	n = os_read_file(fd, buf, size);
67 	if(n != size){
68 		printk("Read of %d bytes from '%s' failed, err = %d\n", size,
69 		       filename, -n);
70 		return -1;
71 	}
72 
73 	os_close_file(fd);
74 	return 0;
75 }
76