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/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 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 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 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