1 /////////////////////////////////////////////////////////////////////////////// 2 // 3 /// \file powerpc.c 4 /// \brief Filter for PowerPC (big endian) 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 powerpc_code(lzma_simple *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 // PowerPC branch 6(48) 24(Offset) 1(Abs) 1(Link) 25 if ((buffer[i] >> 2) == 0x12 26 && ((buffer[i + 3] & 3) == 1)) { 27 28 const uint32_t src = ((buffer[i + 0] & 3) << 24) 29 | (buffer[i + 1] << 16) 30 | (buffer[i + 2] << 8) 31 | (buffer[i + 3] & (~3)); 32 33 uint32_t dest; 34 if (is_encoder) 35 dest = now_pos + (uint32_t)(i) + src; 36 else 37 dest = src - (now_pos + (uint32_t)(i)); 38 39 buffer[i + 0] = 0x48 | ((dest >> 24) & 0x03); 40 buffer[i + 1] = (dest >> 16); 41 buffer[i + 2] = (dest >> 8); 42 buffer[i + 3] &= 0x03; 43 buffer[i + 3] |= dest; 44 } 45 } 46 47 return i; 48 } 49 50 51 static lzma_ret 52 powerpc_coder_init(lzma_next_coder *next, const lzma_allocator *allocator, 53 const lzma_filter_info *filters, bool is_encoder) 54 { 55 return lzma_simple_coder_init(next, allocator, filters, 56 &powerpc_code, 0, 4, 4, is_encoder); 57 } 58 59 60 extern lzma_ret 61 lzma_simple_powerpc_encoder_init(lzma_next_coder *next, 62 const lzma_allocator *allocator, 63 const lzma_filter_info *filters) 64 { 65 return powerpc_coder_init(next, allocator, filters, true); 66 } 67 68 69 extern lzma_ret 70 lzma_simple_powerpc_decoder_init(lzma_next_coder *next, 71 const lzma_allocator *allocator, 72 const lzma_filter_info *filters) 73 { 74 return powerpc_coder_init(next, allocator, filters, false); 75 } 76