1*4d495c6eSApple OSS Distributions /*
2*4d495c6eSApple OSS Distributions * Copyright (c) 2025 Apple Computer, Inc. All rights reserved.
3*4d495c6eSApple OSS Distributions *
4*4d495c6eSApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*4d495c6eSApple OSS Distributions *
6*4d495c6eSApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code
7*4d495c6eSApple OSS Distributions * as defined in and that are subject to the Apple Public Source License
8*4d495c6eSApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in
9*4d495c6eSApple OSS Distributions * compliance with the License. The rights granted to you under the License
10*4d495c6eSApple OSS Distributions * may not be used to create, or enable the creation or redistribution of,
11*4d495c6eSApple OSS Distributions * unlawful or unlicensed copies of an Apple operating system, or to
12*4d495c6eSApple OSS Distributions * circumvent, violate, or enable the circumvention or violation of, any
13*4d495c6eSApple OSS Distributions * terms of an Apple operating system software license agreement.
14*4d495c6eSApple OSS Distributions *
15*4d495c6eSApple OSS Distributions * Please obtain a copy of the License at
16*4d495c6eSApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*4d495c6eSApple OSS Distributions *
18*4d495c6eSApple OSS Distributions * The Original Code and all software distributed under the License are
19*4d495c6eSApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*4d495c6eSApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*4d495c6eSApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*4d495c6eSApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*4d495c6eSApple OSS Distributions * Please see the License for the specific language governing rights and
24*4d495c6eSApple OSS Distributions * limitations under the License.
25*4d495c6eSApple OSS Distributions *
26*4d495c6eSApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*4d495c6eSApple OSS Distributions */
28*4d495c6eSApple OSS Distributions #include <mach/vm_param.h>
29*4d495c6eSApple OSS Distributions #include <stdint.h>
30*4d495c6eSApple OSS Distributions
31*4d495c6eSApple OSS Distributions #define _STR(X) #X
32*4d495c6eSApple OSS Distributions #define STR(X) _STR(X)
33*4d495c6eSApple OSS Distributions
34*4d495c6eSApple OSS Distributions void start() asm ("start");
35*4d495c6eSApple OSS Distributions
36*4d495c6eSApple OSS Distributions /*
37*4d495c6eSApple OSS Distributions * A library-free routine to return the number of bytes in a pointer. This
38*4d495c6eSApple OSS Distributions * allows us to test the kernel loader policy without having an external
39*4d495c6eSApple OSS Distributions * dependency on dyld and/or the presence of a slice in a library dependency
40*4d495c6eSApple OSS Distributions * (which it often does not, even if the kernel supports the policy).
41*4d495c6eSApple OSS Distributions *
42*4d495c6eSApple OSS Distributions * No C code. The stack is not guaranteed to be aligned yet.
43*4d495c6eSApple OSS Distributions */
44*4d495c6eSApple OSS Distributions __attribute__((naked, noreturn))
45*4d495c6eSApple OSS Distributions void
start()46*4d495c6eSApple OSS Distributions start()
47*4d495c6eSApple OSS Distributions {
48*4d495c6eSApple OSS Distributions /* exit(__WORDSIZE/8) */
49*4d495c6eSApple OSS Distributions asm volatile (
50*4d495c6eSApple OSS Distributions "mov x0, " STR(__WORDSIZE/8) "\n"
51*4d495c6eSApple OSS Distributions "mov x16, #1\n"
52*4d495c6eSApple OSS Distributions "svc #(" STR(SWI_SYSCALL) ")\n");
53*4d495c6eSApple OSS Distributions }
54