Home | History | Annotate | Line # | Download | only in simple 
      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 &= ~(size_t)3;
     22 
     23 	size_t i;
     24 	for (i = 0; i < size; i += 4) {
     25 		if (buffer[i + 3] == 0xEB) {
     26 			uint32_t src = ((uint32_t)(buffer[i + 2]) << 16)
     27 					| ((uint32_t)(buffer[i + 1]) << 8)
     28 					| (uint32_t)(buffer[i + 0]);
     29 			src <<= 2;
     30 
     31 			uint32_t dest;
     32 			if (is_encoder)
     33 				dest = now_pos + (uint32_t)(i) + 8 + src;
     34 			else
     35 				dest = src - (now_pos + (uint32_t)(i) + 8);
     36 
     37 			dest >>= 2;
     38 			buffer[i + 2] = (dest >> 16);
     39 			buffer[i + 1] = (dest >> 8);
     40 			buffer[i + 0] = dest;
     41 		}
     42 	}
     43 
     44 	return i;
     45 }
     46 
     47 
     48 static lzma_ret
     49 arm_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
     50 		const lzma_filter_info *filters, bool is_encoder)
     51 {
     52 	return lzma_simple_coder_init(next, allocator, filters,
     53 			&arm_code, 0, 4, 4, is_encoder);
     54 }
     55 
     56 
     57 #ifdef HAVE_ENCODER_ARM
     58 extern lzma_ret
     59 lzma_simple_arm_encoder_init(lzma_next_coder *next,
     60 		const lzma_allocator *allocator,
     61 		const lzma_filter_info *filters)
     62 {
     63 	return arm_coder_init(next, allocator, filters, true);
     64 }
     65 #endif
     66 
     67 
     68 #ifdef HAVE_DECODER_ARM
     69 extern lzma_ret
     70 lzma_simple_arm_decoder_init(lzma_next_coder *next,
     71 		const lzma_allocator *allocator,
     72 		const lzma_filter_info *filters)
     73 {
     74 	return arm_coder_init(next, allocator, filters, false);
     75 }
     76 #endif
     77