| | 1 | /* |
| | 2 | * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. |
| | 3 | * |
| | 4 | * @APPLE_LICENSE_OSREFERENCE_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. The rights granted to you under the |
| | 10 | * License may not be used to create, or enable the creation or |
| | 11 | * redistribution of, unlawful or unlicensed copies of an Apple operating |
| | 12 | * system, or to circumvent, violate, or enable the circumvention or |
| | 13 | * violation of, any terms of an Apple operating system software license |
| | 14 | * agreement. |
| | 15 | * |
| | 16 | * Please obtain a copy of the License at |
| | 17 | * http://www.opensource.apple.com/apsl/ and read it before using this |
| | 18 | * file. |
| | 19 | * |
| | 20 | * The Original Code and all software distributed under the License are |
| | 21 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
| | 22 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
| | 23 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
| | 24 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
| | 25 | * Please see the License for the specific language governing rights and |
| | 26 | * limitations under the License. |
| | 27 | * |
| | 28 | * @APPLE_LICENSE_OSREFERENCE_HEADER_END@ |
| | 29 | */ |
| | 30 | /* |
| | 31 | 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. |
| | 32 | |
| | 33 | If you do any maintenance on any of the following files make sure great care is taken to keep them in Sync. |
| | 34 | KernelModule.bproj/kmod.make |
| | 35 | KernelModule.bproj/CreateKModInfo.perl |
| | 36 | KernelModule.bproj/kmodc++/pure.c |
| | 37 | KernelModule.bproj/kmodc++/cplus_start.c |
| | 38 | KernelModule.bproj/kmodc++/cplus_start.c |
| | 39 | KernelModule.bproj/kmodc/c_start.c |
| | 40 | KernelModule.bproj/kmodc/c_stop.c |
| | 41 | |
| | 42 | 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. |
| | 43 | |
| | 44 | The linkline must look like this. |
| | 45 | *.o -lkmodc++ kmod_info.o -lkmod |
| | 46 | */ |
| | 47 | #include <mach/mach_types.h> |
| | 48 | |
| | 49 | // These global symbols will be defined by CreateInfo script's info.c file. |
| | 50 | extern kmod_start_func_t *_realmain; |
| | 51 | |
| | 52 | __private_extern__ kern_return_t _start(kmod_info_t *ki, void *data) |
| | 53 | { |
| | 54 | if (_realmain) |
| | 55 | return (*_realmain)(ki, data); |
| | 56 | else |
| | 57 | return KERN_SUCCESS; |
| | 58 | } |
projects / apple / xnu.git / blame_incremental