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1 | /* |
2 | * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. | |
3 | * | |
8f6c56a5 | 4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
1c79356b | 5 | * |
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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. The rights granted to you under the License | |
10 | * may not be used to create, or enable the creation or redistribution of, | |
11 | * unlawful or unlicensed copies of an Apple operating system, or to | |
12 | * circumvent, violate, or enable the circumvention or violation of, any | |
13 | * terms of an Apple operating system software license agreement. | |
14 | * | |
15 | * Please obtain a copy of the License at | |
16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. | |
17 | * | |
18 | * The Original Code and all software distributed under the License are | |
19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, | |
21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. | |
23 | * Please see the License for the specific language governing rights and | |
8ad349bb | 24 | * limitations under the License. |
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25 | * |
26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ | |
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27 | */ |
28 | /* | |
29 | Subtle combination of files and libraries make up the C++ runtime system for kernel modules. We are dependant on the KernelModule kmod.make and CreateKModInfo.perl scripts to be exactly instep with both this library module and the libkmod module as well. | |
30 | ||
31 | If you do any maintenance on any of the following files make sure great care is taken to keep them in Sync. | |
32 | KernelModule.bproj/kmod.make | |
33 | KernelModule.bproj/CreateKModInfo.perl | |
34 | KernelModule.bproj/kmodc++/pure.c | |
35 | KernelModule.bproj/kmodc++/cplus_start.c | |
36 | KernelModule.bproj/kmodc++/cplus_start.c | |
37 | KernelModule.bproj/kmodc/c_start.c | |
38 | KernelModule.bproj/kmodc/c_stop.c | |
39 | ||
40 | The trick is that the linkline links all of the developers modules. If any static constructors are used .constructors_used will be left as an undefined symbol. This symbol is exported by the cplus_start.c routine which automatically brings in the appropriate C++ _start routine. However the actual _start symbol is only required by the kmod_info structure that is created and initialized by the CreateKModInfo.perl script. If no C++ was used the _start will be an undefined symbol that is finally satisfied by the c_start module in the kmod library. | |
41 | ||
42 | The linkline must look like this. | |
43 | *.o -lkmodc++ kmod_info.o -lkmod | |
44 | */ | |
45 | #include <mach/mach_types.h> | |
46 | ||
47 | asm(".constructors_used = 0"); | |
48 | asm(".private_extern .constructors_used"); | |
49 | ||
50 | // This global symbols will be defined by CreateInfo script's info.c file. | |
51 | extern kmod_start_func_t *_realmain; | |
52 | ||
53 | // Functions defined in libkern/c++/OSRuntime.cpp | |
54 | extern kern_return_t OSRuntimeInitializeCPP(kmod_info_t *ki, void *data); | |
55 | ||
56 | __private_extern__ kern_return_t _start(kmod_info_t *ki, void *data) | |
57 | { | |
58 | kern_return_t res = OSRuntimeInitializeCPP(ki, data); | |
59 | ||
60 | if (!res && _realmain) | |
61 | res = (*_realmain)(ki, data); | |
62 | ||
63 | return res; | |
64 | } |