src/atomics/init.c

   1 /*
   2  * Copyright (c) 2013 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #include <limits.h>
  25 #include <stdint.h>
  26 #include <stdlib.h>
  27 #include <machine/cpu_capabilities.h>
  28
  29 #include <_simple.h>
  30
  31 #include <platform/string.h>
  32 #include <platform/compat.h>
  33
  34 #include "OSAtomicFifo.h"
  35
  36 __attribute__ ((visibility ("hidden")))
  37 void *COMMPAGE_PFZ_BASE_PTR commpage_pfz_base = 0;
  38
  39 __attribute__ ((visibility ("hidden")))
  40 void
  41 __pfz_setup(const char *apple[])
  42 {
  43     const char *p = _simple_getenv(apple, "pfz");
  44         uintptr_t base = 0;
  45     if (p != NULL) {
  46         const char *q;
  47
  48         /* We are given hex starting with 0x */
  49         if (p[0] != '0' || p[1] != 'x') {
  50             goto __pfz_setup_clear;
  51         }
  52
  53         for (q = p + 2; *q; q++) {
  54             base <<= 4; // *= 16
  55
  56             if ('0' <= *q && *q <= '9') {
  57                 base += *q - '0';
  58             } else if ('a' <= *q && *q <= 'f') {
  59                 base += *q - 'a' + 10;
  60             } else if ('A' <= *q && *q <= 'F') {
  61                 base += *q - 'A' + 10;
  62             } else {
  63                 base=0;
  64                 goto __pfz_setup_clear;
  65             }
  66         }
  67
  68 __pfz_setup_clear:
  69         bzero((void *)((uintptr_t)p - 4), strlen(p) + 4);
  70     }
  71
  72         if (base != 0) {
  73                 commpage_pfz_base = base;
  74         }
  75 }
  76