xref: /openbmc/linux/arch/um/kernel/initrd.c (revision 87c2ce3b)
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 "user_util.h"
11 #include "kern_util.h"
12 #include "initrd.h"
13 #include "init.h"
14 #include "os.h"
15 
16 /* Changed by uml_initrd_setup, which is a setup */
17 static char *initrd __initdata = NULL;
18 
19 static int __init read_initrd(void)
20 {
21 	void *area;
22 	long long size;
23 	int err;
24 
25 	if(initrd == NULL) return 0;
26 	err = os_file_size(initrd, &size);
27 	if(err) return 0;
28 	area = alloc_bootmem(size);
29 	if(area == NULL) return 0;
30 	if(load_initrd(initrd, area, size) == -1) return 0;
31 	initrd_start = (unsigned long) area;
32 	initrd_end = initrd_start + size;
33 	return 0;
34 }
35 
36 __uml_postsetup(read_initrd);
37 
38 static int __init uml_initrd_setup(char *line, int *add)
39 {
40 	initrd = line;
41 	return 0;
42 }
43 
44 __uml_setup("initrd=", uml_initrd_setup,
45 "initrd=<initrd image>\n"
46 "    This is used to boot UML from an initrd image.  The argument is the\n"
47 "    name of the file containing the image.\n\n"
48 );
49 
50 int load_initrd(char *filename, void *buf, int size)
51 {
52 	int fd, n;
53 
54 	fd = os_open_file(filename, of_read(OPENFLAGS()), 0);
55 	if(fd < 0){
56 		printk("Opening '%s' failed - err = %d\n", filename, -fd);
57 		return(-1);
58 	}
59 	n = os_read_file(fd, buf, size);
60 	if(n != size){
61 		printk("Read of %d bytes from '%s' failed, err = %d\n", size,
62 		       filename, -n);
63 		return(-1);
64 	}
65 
66 	os_close_file(fd);
67 	return(0);
68 }
69 /*
70  * Overrides for Emacs so that we follow Linus's tabbing style.
71  * Emacs will notice this stuff at the end of the file and automatically
72  * adjust the settings for this buffer only.  This must remain at the end
73  * of the file.
74  * ---------------------------------------------------------------------------
75  * Local variables:
76  * c-file-style: "linux"
77  * End:
78  */
79