kernel/krtld/kobj_subr.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #pragma ident   "%Z%%M% %I%     %E% SMI"
  27
  28 #include <sys/types.h>
  29 #include <sys/param.h>
  30 #include <sys/systm.h>
  31
  32 #include <sys/bootconf.h>
  33 #include <sys/kobj_impl.h>
  34 #include <sys/cmn_err.h>
  35
  36 /*
  37  * Standalone utility functions for use within krtld.
  38  * Many platforms implement optimized platmod versions of
  39  * utilities such as bcopy and any such are not yet available
  40  * until the kernel is more completely stitched together.
  41  * These standalones are referenced through vectors
  42  * kobj_bzero, etc.  Throughout krtld, the usual utility
  43  * is redefined to reference through the corresponding
  44  * vector so that krtld may simply refer to bzero etc.
  45  * as usual.  See kobj_impl.h.
  46  */
  47
  48 /*ARGSUSED*/
  49 static void
  50 kprintf(void *op, const char *fmt, ...)
  51 {
  52         va_list adx;
  53
  54         va_start(adx, fmt);
  55         vprintf(fmt, adx);
  56         va_end(adx);
  57 }
  58
  59 static void
  60 stand_bzero(void *p_arg, size_t count)
  61 {
  62         char zero = 0;
  63         caddr_t p = p_arg;
  64
  65         while (count != 0)
  66                 *p++ = zero, count--;
  67 }
  68
  69 static void
  70 stand_bcopy(const void *src_arg, void *dest_arg, size_t count)
  71 {
  72         caddr_t src = (caddr_t)src_arg;
  73         caddr_t dest = dest_arg;
  74
  75         if (src < dest && (src + count) > dest) {
  76                 /* overlap copy */
  77                 while (--count != -1)
  78                         *(dest + count) = *(src + count);
  79         } else {
  80                 while (--count != -1)
  81                         *dest++ = *src++;
  82         }
  83 }
  84
  85 static size_t
  86 stand_strlcat(char *dst, const char *src, size_t dstsize)
  87 {
  88         char *df = dst;
  89         size_t left = dstsize;
  90         size_t l1;
  91         size_t l2 = strlen(src);
  92         size_t copied;
  93
  94         while (left-- != 0 && *df != '\0')
  95                 df++;
  96         l1 = df - dst;
  97         if (dstsize == l1)
  98                 return (l1 + l2);
  99
 100         copied = l1 + l2 >= dstsize ? dstsize - l1 - 1 : l2;
 101         bcopy(src, dst + l1, copied);
 102         dst[l1+copied] = '\0';
 103         return (l1 + l2);
 104 }
 105
 106 /*
 107  * Set up the krtld standalone utilty vectors
 108  */
 109 void
 110 kobj_setup_standalone_vectors()
 111 {
 112         _kobj_printf = (void (*)(void *, const char *, ...))bop_printf;
 113         kobj_bcopy = stand_bcopy;
 114         kobj_bzero = stand_bzero;
 115         kobj_strlcat = stand_strlcat;
 116 }
 117
 118 /*
 119  * Restore the kprintf/bcopy/bzero kobj vectors.
 120  * We need to undefine the override macros to
 121  * accomplish this.
 122  *
 123  * Do NOT add new code after the point or at least
 124  * certainly not code using bcopy or bzero which would
 125  * need to be vectored to the krtld equivalents.
 126  */
 127 #undef  bcopy
 128 #undef  bzero
 129 #undef  strlcat
 130
 131 void
 132 kobj_restore_vectors()
 133 {
 134         _kobj_printf = kprintf;
 135         kobj_bcopy = bcopy;
 136         kobj_bzero = bzero;
 137         kobj_strlcat = strlcat;
 138 }