com32/lib/syslinux/initramfs.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2007-2008 H. Peter Anvin - All Rights Reserved
   4  *
   5  *   Permission is hereby granted, free of charge, to any person
   6  *   obtaining a copy of this software and associated documentation
   7  *   files (the "Software"), to deal in the Software without
   8  *   restriction, including without limitation the rights to use,
   9  *   copy, modify, merge, publish, distribute, sublicense, and/or
  10  *   sell copies of the Software, and to permit persons to whom
  11  *   the Software is furnished to do so, subject to the following
  12  *   conditions:
  13  *
  14  *   The above copyright notice and this permission notice shall
  15  *   be included in all copies or substantial portions of the Software.
  16  *
  17  *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  18  *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  19  *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  20  *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  21  *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  22  *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23  *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  24  *   OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  * ----------------------------------------------------------------------- */
  27
  28 /*
  29  * initramfs.c
  30  *
  31  * Utility functions for initramfs manipulation
  32  */
  33
  34 #include <stdlib.h>
  35 #include <syslinux/linux.h>
  36
  37 struct initramfs *initramfs_init(void)
  38 {
  39     struct initramfs *ir;
  40
  41     ir = calloc(sizeof(*ir), 1);
  42     if (!ir)
  43         return NULL;
  44
  45     ir->prev = ir->next = ir;
  46     return ir;
  47 }
  48
  49 int initramfs_add_data(struct initramfs *ihead, const void *data,
  50                        size_t data_len, size_t len, size_t align)
  51 {
  52     struct initramfs *in;
  53
  54     if (!len)
  55         return 0;               /* Nothing to add... */
  56
  57     /* Alignment must be a power of 2, and <= INITRAMFS_MAX_ALIGN */
  58     if (!align || (align & (align - 1)) || align > INITRAMFS_MAX_ALIGN)
  59         return -1;
  60
  61     in = malloc(sizeof(*in));
  62     if (!in)
  63         return -1;
  64
  65     in->len = len;
  66     in->data = data;
  67     in->data_len = data_len;
  68     in->align = align;
  69
  70     in->next = ihead;
  71     in->prev = ihead->prev;
  72     ihead->prev->next = in;
  73     ihead->prev = in;
  74
  75     return 0;
  76 }