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 static 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 if (area == NULL) 41 return 0; 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 51 __uml_postsetup(read_initrd); 52 53 static int __init uml_initrd_setup(char *line, int *add) 54 { 55 initrd = line; 56 return 0; 57 } 58 59 __uml_setup("initrd=", uml_initrd_setup, 60 "initrd=<initrd image>\n" 61 " This is used to boot UML from an initrd image. The argument is the\n" 62 " name of the file containing the image.\n\n" 63 ); 64 65 static int load_initrd(char *filename, void *buf, int size) 66 { 67 int fd, n; 68 69 fd = os_open_file(filename, of_read(OPENFLAGS()), 0); 70 if (fd < 0) { 71 printk(KERN_ERR "Opening '%s' failed - err = %d\n", filename, 72 -fd); 73 return -1; 74 } 75 n = os_read_file(fd, buf, size); 76 if (n != size) { 77 printk(KERN_ERR "Read of %d bytes from '%s' failed, " 78 "err = %d\n", size, 79 filename, -n); 80 return -1; 81 } 82 83 os_close_file(fd); 84 return 0; 85 } 86