| /* |
| * Copyright 2012 Google Inc. |
| * |
| * See file CREDITS for list of people who contributed to this |
| * project. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License as |
| * published by the Free Software Foundation; either version 2 of |
| * the License, or (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but without any warranty; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| * MA 02111-1307 USA |
| */ |
| |
| #include <elf.h> |
| #include <stdio.h> |
| |
| #include "base/container_of.h" |
| #include "base/lzma/lzma.h" |
| #include "base/xalloc.h" |
| #include "module/module.h" |
| #include "module/symbols.h" |
| #include "module/trampoline/trampoline.h" |
| |
| int start_module(const void *compressed_image, uint32_t size) |
| { |
| // Put the decompressed module at the end of the trampoline. |
| Elf32_Ehdr *elf = (Elf32_Ehdr *)&_tramp_end; |
| |
| //XXX This is a hack for now which assumes the decompression area |
| // ends at the end of the kernel area. Once some sort of global |
| // memory allocator exists which can keep track of these things |
| // explicitly (as opposed to by convention) then this can go away. |
| uint8_t *decomp_end = (uint8_t *)(uintptr_t)(CONFIG_KERNEL_START + |
| CONFIG_KERNEL_SIZE); |
| |
| // Decompress the trampoline itself. |
| uint32_t out_size = ulzman(&_binary_trampoline_start, |
| (uintptr_t)&_binary_trampoline_size, |
| (unsigned char *)elf, |
| decomp_end - &_tramp_end); |
| if (!out_size) { |
| printf("Error decompressing trampoline.\n"); |
| return -1; |
| } |
| |
| // Expand the trampoline into place. |
| if (elf_check_header(elf)) |
| return -1; |
| elf_load(elf); |
| |
| // Decompress the target image. |
| out_size = ulzman(compressed_image, size, (unsigned char *)elf, |
| decomp_end - &_tramp_end); |
| if (!out_size) { |
| printf("Error decompressing module.\n"); |
| return -1; |
| } |
| |
| // Do some basic checks on the headers. |
| if (elf_check_header(elf)) |
| return -1; |
| |
| enter_trampoline(elf); |
| |
| // We should never actually reach the end of this function. |
| return 0; |
| } |
| |
| static int dc_module_default_start(DcModuleOps *me) |
| { |
| DcModule *module = container_of(me, DcModule, ops); |
| |
| int size = storage_size(module->storage); |
| if (size < 0) |
| return 1; |
| |
| void *image = xmalloc(size); |
| if (storage_read(module->storage, image, 0, size)) { |
| free(image); |
| return 1; |
| } |
| |
| start_module(image, size); |
| free(image); |
| // If we ever get back to this function, something didn't work. |
| return 1; |
| } |
| |
| DcModule *new_dc_module(StorageOps *storage) |
| { |
| DcModule *module = xzalloc(sizeof(*module)); |
| module->ops.start = &dc_module_default_start; |
| module->storage = storage; |
| return module; |
| } |