| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #include "private/KernelArgumentBlock.h" |
| |
| extern const char linker_code_start; |
| extern const char original_start; |
| extern const char linker_entry; |
| |
| /* |
| * This is the entry point for the linker wrapper, which finds |
| * the real linker, then bootstraps into it. |
| */ |
| extern "C" ElfW(Addr) __linker_init(void* raw_args) { |
| KernelArgumentBlock args(raw_args); |
| |
| static uintptr_t linker_offset = reinterpret_cast<uintptr_t>(&linker_code_start); |
| static uintptr_t linktime_addr = reinterpret_cast<uintptr_t>(&linktime_addr); |
| ElfW(Addr) my_addr = reinterpret_cast<uintptr_t>(&linktime_addr) - linktime_addr; |
| |
| // Set AT_ENTRY to the proper entry point |
| for (ElfW(auxv_t)* v = args.auxv; v->a_type != AT_NULL; ++v) { |
| if (v->a_type == AT_BASE) { |
| v->a_un.a_val = my_addr + linker_offset; |
| } |
| if (v->a_type == AT_ENTRY) { |
| v->a_un.a_val = my_addr + reinterpret_cast<uintptr_t>(&original_start); |
| } |
| } |
| |
| // Return address of linker entry point -- may need to ensure that raw_args |
| // was saved. |
| return my_addr + linker_offset + reinterpret_cast<uintptr_t>(&linker_entry); |
| } |