1 // SPDX-License-Identifier: 0BSD 2 3 /////////////////////////////////////////////////////////////////////////////// 4 // 5 /// \file powerpc.c 6 /// \brief Filter for PowerPC (big endian) binaries 7 /// 8 // Authors: Igor Pavlov 9 // Lasse Collin 10 // 11 /////////////////////////////////////////////////////////////////////////////// 12 13 #include "simple_private.h" 14 15 16 static size_t 17 powerpc_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 // PowerPC branch 6(48) 24(Offset) 1(Abs) 1(Link) 24 if ((buffer[i] >> 2) == 0x12 25 && ((buffer[i + 3] & 3) == 1)) { 26 27 const uint32_t src 28 = (((uint32_t)(buffer[i + 0]) & 3) << 24) 29 | ((uint32_t)(buffer[i + 1]) << 16) 30 | ((uint32_t)(buffer[i + 2]) << 8) 31 | ((uint32_t)(buffer[i + 3]) & ~UINT32_C(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 #ifdef HAVE_ENCODER_POWERPC 61 extern lzma_ret 62 lzma_simple_powerpc_encoder_init(lzma_next_coder *next, 63 const lzma_allocator *allocator, 64 const lzma_filter_info *filters) 65 { 66 return powerpc_coder_init(next, allocator, filters, true); 67 } 68 #endif 69 70 71 #ifdef HAVE_DECODER_POWERPC 72 extern lzma_ret 73 lzma_simple_powerpc_decoder_init(lzma_next_coder *next, 74 const lzma_allocator *allocator, 75 const lzma_filter_info *filters) 76 { 77 return powerpc_coder_init(next, allocator, filters, false); 78 } 79 #endif 80