arch/ppc/boot/common/bootinfo.c

   1 /*
   2  * arch/ppc/common/bootinfo.c
   3  *
   4  * General bootinfo record utilities
   5  * Author: Randy Vinson <rvinson@mvista.com>
   6  *
   7  * 2002 (c) MontaVista Software, Inc. This file is licensed under the terms
   8  * of the GNU General Public License version 2. This program is licensed
   9  * "as is" without any warranty of any kind, whether express or implied.
  10  */
  11
  12 #include <linux/types.h>
  13 #include <linux/string.h>
  14 #include <asm/bootinfo.h>
  15
  16 #include "nonstdio.h"
  17
  18 static struct bi_record * birec = NULL;
  19
  20 static struct bi_record *
  21 __bootinfo_build(struct bi_record *rec, unsigned long tag, unsigned long size,
  22                  void *data)
  23 {
  24         /* set the tag */
  25         rec->tag = tag;
  26
  27         /* if the caller has any data, copy it */
  28         if (size)
  29                 memcpy(rec->data, (char *)data, size);
  30
  31         /* set the record size */
  32         rec->size = sizeof(struct bi_record) + size;
  33
  34         /* advance to the next available space */
  35         rec = (struct bi_record *)((unsigned long)rec + rec->size);
  36
  37         return rec;
  38 }
  39
  40 void
  41 bootinfo_init(struct bi_record *rec)
  42 {
  43
  44         /* save start of birec area */
  45         birec = rec;
  46
  47         /* create an empty list */
  48         rec = __bootinfo_build(rec, BI_FIRST, 0, NULL);
  49         (void) __bootinfo_build(rec, BI_LAST, 0, NULL);
  50
  51 }
  52
  53 void
  54 bootinfo_append(unsigned long tag, unsigned long size, void * data)
  55 {
  56
  57         struct bi_record *rec = birec;
  58
  59         /* paranoia */
  60         if ((rec == NULL) || (rec->tag != BI_FIRST))
  61                 return;
  62
  63         /* find the last entry in the list */
  64         while (rec->tag != BI_LAST)
  65                 rec = (struct bi_record *)((ulong)rec + rec->size);
  66
  67         /* overlay BI_LAST record with new one and tag on a new BI_LAST */
  68         rec = __bootinfo_build(rec, tag, size, data);
  69         (void) __bootinfo_build(rec, BI_LAST, 0, NULL);
  70 }