1 /////////////////////////////////////////////////////////////////////////////// 2 // 3 /// \file arm.c 4 /// \brief Filter for ARM binaries 5 /// 6 // Authors: Igor Pavlov 7 // Lasse Collin 8 // 9 // This file has been put into the public domain. 10 // You can do whatever you want with this file. 11 // 12 /////////////////////////////////////////////////////////////////////////////// 13 14 #include "simple_private.h" 15 16 17 static size_t 18 arm_code(void *simple lzma_attribute((__unused__)), 19 uint32_t now_pos, bool is_encoder, 20 uint8_t *buffer, size_t size) 21 { 22 size_t i; 23 for (i = 0; i + 4 <= size; i += 4) { 24 if (buffer[i + 3] == 0xEB) { 25 uint32_t src = ((uint32_t)(buffer[i + 2]) << 16) 26 | ((uint32_t)(buffer[i + 1]) << 8) 27 | (uint32_t)(buffer[i + 0]); 28 src <<= 2; 29 30 uint32_t dest; 31 if (is_encoder) 32 dest = now_pos + (uint32_t)(i) + 8 + src; 33 else 34 dest = src - (now_pos + (uint32_t)(i) + 8); 35 36 dest >>= 2; 37 buffer[i + 2] = (dest >> 16); 38 buffer[i + 1] = (dest >> 8); 39 buffer[i + 0] = dest; 40 } 41 } 42 43 return i; 44 } 45 46 47 static lzma_ret 48 arm_coder_init(lzma_next_coder *next, const lzma_allocator *allocator, 49 const lzma_filter_info *filters, bool is_encoder) 50 { 51 return lzma_simple_coder_init(next, allocator, filters, 52 &arm_code, 0, 4, 4, is_encoder); 53 } 54 55 56 extern lzma_ret 57 lzma_simple_arm_encoder_init(lzma_next_coder *next, 58 const lzma_allocator *allocator, 59 const lzma_filter_info *filters) 60 { 61 return arm_coder_init(next, allocator, filters, true); 62 } 63 64 65 extern lzma_ret 66 lzma_simple_arm_decoder_init(lzma_next_coder *next, 67 const lzma_allocator *allocator, 68 const lzma_filter_info *filters) 69 { 70 return arm_coder_init(next, allocator, filters, false); 71 } 72