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 17static size_t 18powerpc_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 52static lzma_ret 53powerpc_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 61extern lzma_ret 62lzma_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 69 70extern lzma_ret 71lzma_simple_powerpc_decoder_init(lzma_next_coder *next, 72 const lzma_allocator *allocator, 73 const lzma_filter_info *filters) 74{ 75 return powerpc_coder_init(next, allocator, filters, false); 76} 77