1 // SPDX-License-Identifier: 0BSD 2 3 /////////////////////////////////////////////////////////////////////////////// 4 // 5 /// \file arm.c 6 /// \brief Filter for ARM binaries 7 /// 8 // Authors: Igor Pavlov 9 // Lasse Collin 10 // 11 /////////////////////////////////////////////////////////////////////////////// 12 13 #include "simple_private.h" 14 15 16 static size_t 17 arm_code(void *simple lzma_attribute((__unused__)), 18 uint32_t now_pos, bool is_encoder, 19 uint8_t *buffer, size_t size) 20 { 21 size_t i; 22 for (i = 0; i + 4 <= size; i += 4) { 23 if (buffer[i + 3] == 0xEB) { 24 uint32_t src = ((uint32_t)(buffer[i + 2]) << 16) 25 | ((uint32_t)(buffer[i + 1]) << 8) 26 | (uint32_t)(buffer[i + 0]); 27 src <<= 2; 28 29 uint32_t dest; 30 if (is_encoder) 31 dest = now_pos + (uint32_t)(i) + 8 + src; 32 else 33 dest = src - (now_pos + (uint32_t)(i) + 8); 34 35 dest >>= 2; 36 buffer[i + 2] = (dest >> 16); 37 buffer[i + 1] = (dest >> 8); 38 buffer[i + 0] = dest; 39 } 40 } 41 42 return i; 43 } 44 45 46 static lzma_ret 47 arm_coder_init(lzma_next_coder *next, const lzma_allocator *allocator, 48 const lzma_filter_info *filters, bool is_encoder) 49 { 50 return lzma_simple_coder_init(next, allocator, filters, 51 &arm_code, 0, 4, 4, is_encoder); 52 } 53 54 55 #ifdef HAVE_ENCODER_ARM 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 #endif 64 65 66 #ifdef HAVE_DECODER_ARM 67 extern lzma_ret 68 lzma_simple_arm_decoder_init(lzma_next_coder *next, 69 const lzma_allocator *allocator, 70 const lzma_filter_info *filters) 71 { 72 return arm_coder_init(next, allocator, filters, false); 73 } 74 #endif 75