arch/ppc-sam440/kernel/tags.c

   1 /*
   2     Copyright © 1995-2014, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <inttypes.h>
   7 #include <utility/tagitem.h>
   8
   9 #include "kernel_intern.h"
  10
  11 struct TagItem *krnNextTagItem(struct TagItem **tagListPtr)
  12 {
  13     if (!(*tagListPtr)) return 0;
  14
  15     while(1)
  16     {
  17         switch((*tagListPtr)->ti_Tag)
  18         {
  19             case TAG_MORE:
  20                 if (!((*tagListPtr) = (struct TagItem *)(*tagListPtr)->ti_Data))
  21                     return NULL;
  22                 continue;
  23             case TAG_IGNORE:
  24                 break;
  25
  26             case TAG_END:
  27                 (*tagListPtr) = 0;
  28                 return NULL;
  29
  30             case TAG_SKIP:
  31                 (*tagListPtr) += (*tagListPtr)->ti_Data + 1;
  32                 continue;
  33
  34             default:
  35                 return (struct TagItem *)(*tagListPtr)++;
  36         }
  37
  38         (*tagListPtr)++;
  39     }
  40 }
  41
  42 struct TagItem *krnFindTagItem(Tag tagValue, struct TagItem *tagList)
  43 {
  44     struct TagItem *tag;
  45     struct TagItem *tagptr = tagList;
  46
  47     while((tag = krnNextTagItem(&tagptr)))
  48     {
  49         if (tag->ti_Tag == tagValue)
  50             return tag;
  51     }
  52
  53     return 0;
  54 }
  55
  56 intptr_t krnGetTagData(Tag tagValue, intptr_t defaultVal, struct TagItem *tagList)
  57 {
  58     struct TagItem *ti = 0;
  59
  60     if (tagList && (ti = krnFindTagItem(tagValue, tagList)))
  61         return ti->ti_Data;
  62
  63         return defaultVal;
  64 }
  65