| /////////////////////////////////////////////////////////////////////////////// |
| // |
| /// \file armthumb.c |
| /// \brief Filter for ARM-Thumb binaries |
| // |
| // Copyright (C) 1999-2006 Igor Pavlov |
| // Copyright (C) 2007 Lasse Collin |
| // |
| // This library is free software; you can redistribute it and/or |
| // modify it under the terms of the GNU Lesser General Public |
| // License as published by the Free Software Foundation; either |
| // version 2.1 of the License, or (at your option) any later version. |
| // |
| // This library 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 |
| // Lesser General Public License for more details. |
| // |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| #include "simple_private.h" |
| |
| |
| static size_t |
| armthumb_code(lzma_simple *simple lzma_attribute((unused)), |
| uint32_t now_pos, bool is_encoder, |
| uint8_t *buffer, size_t size) |
| { |
| uint32_t i; |
| for (i = 0; i + 4 <= size; i += 2) { |
| if ((buffer[i + 1] & 0xF8) == 0xF0 |
| && (buffer[i + 3] & 0xF8) == 0xF8) { |
| uint32_t src = ((buffer[i + 1] & 0x7) << 19) |
| | (buffer[i + 0] << 11) |
| | ((buffer[i + 3] & 0x7) << 8) |
| | (buffer[i + 2]); |
| |
| src <<= 1; |
| |
| uint32_t dest; |
| if (is_encoder) |
| dest = now_pos + (uint32_t)(i) + 4 + src; |
| else |
| dest = src - (now_pos + (uint32_t)(i) + 4); |
| |
| dest >>= 1; |
| buffer[i + 1] = 0xF0 | ((dest >> 19) & 0x7); |
| buffer[i + 0] = (dest >> 11); |
| buffer[i + 3] = 0xF8 | ((dest >> 8) & 0x7); |
| buffer[i + 2] = (dest); |
| i += 2; |
| } |
| } |
| |
| return i; |
| } |
| |
| |
| static lzma_ret |
| armthumb_coder_init(lzma_next_coder *next, lzma_allocator *allocator, |
| const lzma_filter_info *filters, bool is_encoder) |
| { |
| return lzma_simple_coder_init(next, allocator, filters, |
| &armthumb_code, 0, 4, is_encoder); |
| } |
| |
| |
| extern lzma_ret |
| lzma_simple_armthumb_encoder_init(lzma_next_coder *next, |
| lzma_allocator *allocator, const lzma_filter_info *filters) |
| { |
| return armthumb_coder_init(next, allocator, filters, true); |
| } |
| |
| |
| extern lzma_ret |
| lzma_simple_armthumb_decoder_init(lzma_next_coder *next, |
| lzma_allocator *allocator, const lzma_filter_info *filters) |
| { |
| return armthumb_coder_init(next, allocator, filters, false); |
| } |