1*19c3b8c2SApple OSS Distributions /* 2*19c3b8c2SApple OSS Distributions * Copyright (c) 2014 Apple Inc. All rights reserved. 3*19c3b8c2SApple OSS Distributions * 4*19c3b8c2SApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5*19c3b8c2SApple OSS Distributions * 6*19c3b8c2SApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code 7*19c3b8c2SApple OSS Distributions * as defined in and that are subject to the Apple Public Source License 8*19c3b8c2SApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in 9*19c3b8c2SApple OSS Distributions * compliance with the License. The rights granted to you under the License 10*19c3b8c2SApple OSS Distributions * may not be used to create, or enable the creation or redistribution of, 11*19c3b8c2SApple OSS Distributions * unlawful or unlicensed copies of an Apple operating system, or to 12*19c3b8c2SApple OSS Distributions * circumvent, violate, or enable the circumvention or violation of, any 13*19c3b8c2SApple OSS Distributions * terms of an Apple operating system software license agreement. 14*19c3b8c2SApple OSS Distributions * 15*19c3b8c2SApple OSS Distributions * Please obtain a copy of the License at 16*19c3b8c2SApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this file. 17*19c3b8c2SApple OSS Distributions * 18*19c3b8c2SApple OSS Distributions * The Original Code and all software distributed under the License are 19*19c3b8c2SApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20*19c3b8c2SApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21*19c3b8c2SApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22*19c3b8c2SApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23*19c3b8c2SApple OSS Distributions * Please see the License for the specific language governing rights and 24*19c3b8c2SApple OSS Distributions * limitations under the License. 25*19c3b8c2SApple OSS Distributions * 26*19c3b8c2SApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27*19c3b8c2SApple OSS Distributions */ 28*19c3b8c2SApple OSS Distributions 29*19c3b8c2SApple OSS Distributions #include <mach/vm_param.h> 30*19c3b8c2SApple OSS Distributions 31*19c3b8c2SApple OSS Distributions /* 32*19c3b8c2SApple OSS Distributions * This file is compiled and linked to be the last .o of the __const section 33*19c3b8c2SApple OSS Distributions * of the __DATA segment (see MakeInc.kernel, lastkernelconstructor is placed 34*19c3b8c2SApple OSS Distributions * in the __LAST segment.) 35*19c3b8c2SApple OSS Distributions * 36*19c3b8c2SApple OSS Distributions * This blank page allows us to safely map the const section RO while the rest 37*19c3b8c2SApple OSS Distributions * of __DATA is RW. This is needed since ld has no way of specifying section size 38*19c3b8c2SApple OSS Distributions * alignment and no straight forward way to specify section ordering. 39*19c3b8c2SApple OSS Distributions */ 40*19c3b8c2SApple OSS Distributions 41*19c3b8c2SApple OSS Distributions #if defined(__arm64__) 42*19c3b8c2SApple OSS Distributions /* PAGE_SIZE on ARM64 is an expression derived from a non-const global variable */ 43*19c3b8c2SApple OSS Distributions #define PAD_SIZE PAGE_MAX_SIZE 44*19c3b8c2SApple OSS Distributions #else 45*19c3b8c2SApple OSS Distributions #define PAD_SIZE PAGE_SIZE 46*19c3b8c2SApple OSS Distributions #endif 47*19c3b8c2SApple OSS Distributions 48*19c3b8c2SApple OSS Distributions static const uint8_t __attribute__((section("__DATA,__const"))) data_const_padding[PAD_SIZE] = {[0 ... PAD_SIZE - 1] = 0xFF}; 49*19c3b8c2SApple OSS Distributions const vm_offset_t __attribute__((section("__DATA,__data"))) _lastkerneldataconst = (vm_offset_t)&data_const_padding[0]; 50*19c3b8c2SApple OSS Distributions const vm_size_t __attribute__((section("__DATA,__data"))) _lastkerneldataconst_padsize = sizeof(data_const_padding); 51