arch/ppc/boot/common/bootinfo.c

   1 /*
   2  * General bootinfo record utilities
   3  * Author: Randy Vinson <rvinson@mvista.com>
   4  *
   5  * 2002 (c) MontaVista Software, Inc. This file is licensed under the terms
   6  * of the GNU General Public License version 2. This program is licensed
   7  * "as is" without any warranty of any kind, whether express or implied.
   8  */
   9
  10 #include <linux/types.h>
  11 #include <linux/string.h>
  12 #include <asm/bootinfo.h>
  13
  14 #include "nonstdio.h"
  15
  16 static struct bi_record * birec = NULL;
  17
  18 static struct bi_record *
  19 __bootinfo_build(struct bi_record *rec, unsigned long tag, unsigned long size,
  20                  void *data)
  21 {
  22         /* set the tag */
  23         rec->tag = tag;
  24
  25         /* if the caller has any data, copy it */
  26         if (size)
  27                 memcpy(rec->data, (char *)data, size);
  28
  29         /* set the record size */
  30         rec->size = sizeof(struct bi_record) + size;
  31
  32         /* advance to the next available space */
  33         rec = (struct bi_record *)((unsigned long)rec + rec->size);
  34
  35         return rec;
  36 }
  37
  38 void
  39 bootinfo_init(struct bi_record *rec)
  40 {
  41
  42         /* save start of birec area */
  43         birec = rec;
  44
  45         /* create an empty list */
  46         rec = __bootinfo_build(rec, BI_FIRST, 0, NULL);
  47         (void) __bootinfo_build(rec, BI_LAST, 0, NULL);
  48
  49 }
  50
  51 void
  52 bootinfo_append(unsigned long tag, unsigned long size, void * data)
  53 {
  54
  55         struct bi_record *rec = birec;
  56
  57         /* paranoia */
  58         if ((rec == NULL) || (rec->tag != BI_FIRST))
  59                 return;
  60
  61         /* find the last entry in the list */
  62         while (rec->tag != BI_LAST)
  63                 rec = (struct bi_record *)((ulong)rec + rec->size);
  64
  65         /* overlay BI_LAST record with new one and tag on a new BI_LAST */
  66         rec = __bootinfo_build(rec, tag, size, data);
  67         (void) __bootinfo_build(rec, BI_LAST, 0, NULL);
  68 }