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(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 // 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 29 = (((uint32_t)(buffer[i + 0]) & 3) << 24) 30 | ((uint32_t)(buffer[i + 1]) << 16) 31 | ((uint32_t)(buffer[i + 2]) << 8) 32 | ((uint32_t)(buffer[i + 3]) & ~UINT32_C(3)); 33 34 uint32_t dest; 35 if (is_encoder) 36 dest = now_pos + (uint32_t)(i) + src; 37 else 38 dest = src - (now_pos + (uint32_t)(i)); 39 40 buffer[i + 0] = 0x48 | ((dest >> 24) & 0x03); 41 buffer[i + 1] = (dest >> 16); 42 buffer[i + 2] = (dest >> 8); 43 buffer[i + 3] &= 0x03; 44 buffer[i + 3] |= dest; 45 } 46 } 47 48 return i; 49 } 50 51 52 static lzma_ret 53 powerpc_coder_init(lzma_next_coder *next, const lzma_allocator *allocator, 54 const lzma_filter_info *filters, bool is_encoder) 55 { 56 return lzma_simple_coder_init(next, allocator, filters, 57 &powerpc_code, 0, 4, 4, is_encoder); 58 } 59 60 61 #ifdef HAVE_ENCODER_POWERPC 62 extern lzma_ret 63 lzma_simple_powerpc_encoder_init(lzma_next_coder *next, 64 const lzma_allocator *allocator, 65 const lzma_filter_info *filters) 66 { 67 return powerpc_coder_init(next, allocator, filters, true); 68 } 69 #endif 70 71 72 #ifdef HAVE_DECODER_POWERPC 73 extern lzma_ret 74 lzma_simple_powerpc_decoder_init(lzma_next_coder *next, 75 const lzma_allocator *allocator, 76 const lzma_filter_info *filters) 77 { 78 return powerpc_coder_init(next, allocator, filters, false); 79 } 80 #endif 81