1 /* 2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.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 <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 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 = alloc_bootmem(size); 40 41 if (load_initrd(initrd, area, size) == -1) 42 return 0; 43 44 initrd_start = (unsigned long) area; 45 initrd_end = initrd_start + size; 46 return 0; 47 } 48 49 static int __init uml_initrd_setup(char *line, int *add) 50 { 51 initrd = line; 52 return 0; 53 } 54 55 __uml_setup("initrd=", uml_initrd_setup, 56 "initrd=<initrd image>\n" 57 " This is used to boot UML from an initrd image. The argument is the\n" 58 " name of the file containing the image.\n\n" 59 ); 60 61 static int load_initrd(char *filename, void *buf, int size) 62 { 63 int fd, n; 64 65 fd = os_open_file(filename, of_read(OPENFLAGS()), 0); 66 if (fd < 0) { 67 printk(KERN_ERR "Opening '%s' failed - err = %d\n", filename, 68 -fd); 69 return -1; 70 } 71 n = os_read_file(fd, buf, size); 72 if (n != size) { 73 printk(KERN_ERR "Read of %d bytes from '%s' failed, " 74 "err = %d\n", size, 75 filename, -n); 76 return -1; 77 } 78 79 os_close_file(fd); 80 return 0; 81 } 82