1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 */
5
6 #include <linux/init.h>
7 #include <linux/memblock.h>
8 #include <linux/initrd.h>
9 #include <asm/types.h>
10 #include <init.h>
11 #include <os.h>
12
13 /* Changed by uml_initrd_setup, which is a setup */
14 static char *initrd __initdata = NULL;
15 static int load_initrd(char *filename, void *buf, int size);
16
read_initrd(void)17 int __init read_initrd(void)
18 {
19 void *area;
20 long long size;
21 int err;
22
23 if (initrd == NULL)
24 return 0;
25
26 err = os_file_size(initrd, &size);
27 if (err)
28 return 0;
29
30 /*
31 * This is necessary because alloc_bootmem craps out if you
32 * ask for no memory.
33 */
34 if (size == 0) {
35 printk(KERN_ERR "\"%s\" is a zero-size initrd\n", initrd);
36 return 0;
37 }
38
39 area = memblock_alloc(size, SMP_CACHE_BYTES);
40 if (!area)
41 panic("%s: Failed to allocate %llu bytes\n", __func__, size);
42
43 if (load_initrd(initrd, area, size) == -1)
44 return 0;
45
46 initrd_start = (unsigned long) area;
47 initrd_end = initrd_start + size;
48 return 0;
49 }
50
uml_initrd_setup(char * line,int * add)51 static int __init uml_initrd_setup(char *line, int *add)
52 {
53 initrd = line;
54 return 0;
55 }
56
57 __uml_setup("initrd=", uml_initrd_setup,
58 "initrd=<initrd image>\n"
59 " This is used to boot UML from an initrd image. The argument is the\n"
60 " name of the file containing the image.\n\n"
61 );
62
load_initrd(char * filename,void * buf,int size)63 static int load_initrd(char *filename, void *buf, int size)
64 {
65 int fd, n;
66
67 fd = os_open_file(filename, of_read(OPENFLAGS()), 0);
68 if (fd < 0) {
69 printk(KERN_ERR "Opening '%s' failed - err = %d\n", filename,
70 -fd);
71 return -1;
72 }
73 n = os_read_file(fd, buf, size);
74 if (n != size) {
75 printk(KERN_ERR "Read of %d bytes from '%s' failed, "
76 "err = %d\n", size,
77 filename, -n);
78 return -1;
79 }
80
81 os_close_file(fd);
82 return 0;
83 }
84