arch/um/kernel/initrd.c

   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 "kern_util.h"
  11 #include "initrd.h"
  12 #include "init.h"
  13 #include "os.h"
  14
  15 /* Changed by uml_initrd_setup, which is a setup */
  16 static char *initrd __initdata = NULL;
  17
  18 static int __init read_initrd(void)
  19 {
  20         void *area;
  21         long long size;
  22         int err;
  23
  24         if(initrd == NULL)
  25                 return 0;
  26
  27         err = os_file_size(initrd, &size);
  28         if(err)
  29                 return 0;
  30
  31         area = alloc_bootmem(size);
  32         if(area == NULL)
  33                 return 0;
  34
  35         if(load_initrd(initrd, area, size) == -1)
  36                 return 0;
  37
  38         initrd_start = (unsigned long) area;
  39         initrd_end = initrd_start + size;
  40         return 0;
  41 }
  42
  43 __uml_postsetup(read_initrd);
  44
  45 static int __init uml_initrd_setup(char *line, int *add)
  46 {
  47         initrd = line;
  48         return 0;
  49 }
  50
  51 __uml_setup("initrd=", uml_initrd_setup,
  52 "initrd=<initrd image>\n"
  53 "    This is used to boot UML from an initrd image.  The argument is the\n"
  54 "    name of the file containing the image.\n\n"
  55 );
  56
  57 int load_initrd(char *filename, void *buf, int size)
  58 {
  59         int fd, n;
  60
  61         fd = os_open_file(filename, of_read(OPENFLAGS()), 0);
  62         if(fd < 0){
  63                 printk("Opening '%s' failed - err = %d\n", filename, -fd);
  64                 return -1;
  65         }
  66         n = os_read_file(fd, buf, size);
  67         if(n != size){
  68                 printk("Read of %d bytes from '%s' failed, err = %d\n", size,
  69                        filename, -n);
  70                 return -1;
  71         }
  72
  73         os_close_file(fd);
  74         return 0;
  75 }