xref: /freebsd/contrib/xz/src/liblzma/simple/powerpc.c (revision 3b35e7ee8de9b0260149a2b77e87a2b9c7a36244)
1*3b35e7eeSXin LI // SPDX-License-Identifier: 0BSD
2*3b35e7eeSXin LI 
381ad8388SMartin Matuska ///////////////////////////////////////////////////////////////////////////////
481ad8388SMartin Matuska //
581ad8388SMartin Matuska /// \file       powerpc.c
681ad8388SMartin Matuska /// \brief      Filter for PowerPC (big endian) binaries
781ad8388SMartin Matuska ///
881ad8388SMartin Matuska //  Authors:    Igor Pavlov
981ad8388SMartin Matuska //              Lasse Collin
1081ad8388SMartin Matuska //
1181ad8388SMartin Matuska ///////////////////////////////////////////////////////////////////////////////
1281ad8388SMartin Matuska 
1381ad8388SMartin Matuska #include "simple_private.h"
1481ad8388SMartin Matuska 
1581ad8388SMartin Matuska 
1681ad8388SMartin Matuska static size_t
171456f0f9SXin LI powerpc_code(void *simple lzma_attribute((__unused__)),
1881ad8388SMartin Matuska 		uint32_t now_pos, bool is_encoder,
1981ad8388SMartin Matuska 		uint8_t *buffer, size_t size)
2081ad8388SMartin Matuska {
2181ad8388SMartin Matuska 	size_t i;
2281ad8388SMartin Matuska 	for (i = 0; i + 4 <= size; i += 4) {
2381ad8388SMartin Matuska 		// PowerPC branch 6(48) 24(Offset) 1(Abs) 1(Link)
2481ad8388SMartin Matuska 		if ((buffer[i] >> 2) == 0x12
2581ad8388SMartin Matuska 				&& ((buffer[i + 3] & 3) == 1)) {
2681ad8388SMartin Matuska 
27a8675d92SXin LI 			const uint32_t src
28a8675d92SXin LI 				= (((uint32_t)(buffer[i + 0]) & 3) << 24)
29a8675d92SXin LI 				| ((uint32_t)(buffer[i + 1]) << 16)
30a8675d92SXin LI 				| ((uint32_t)(buffer[i + 2]) << 8)
31a8675d92SXin LI 				| ((uint32_t)(buffer[i + 3]) & ~UINT32_C(3));
3281ad8388SMartin Matuska 
3381ad8388SMartin Matuska 			uint32_t dest;
3481ad8388SMartin Matuska 			if (is_encoder)
3581ad8388SMartin Matuska 				dest = now_pos + (uint32_t)(i) + src;
3681ad8388SMartin Matuska 			else
3781ad8388SMartin Matuska 				dest = src - (now_pos + (uint32_t)(i));
3881ad8388SMartin Matuska 
3981ad8388SMartin Matuska 			buffer[i + 0] = 0x48 | ((dest >> 24) &  0x03);
4081ad8388SMartin Matuska 			buffer[i + 1] = (dest >> 16);
4181ad8388SMartin Matuska 			buffer[i + 2] = (dest >> 8);
4281ad8388SMartin Matuska 			buffer[i + 3] &= 0x03;
4381ad8388SMartin Matuska 			buffer[i + 3] |= dest;
4481ad8388SMartin Matuska 		}
4581ad8388SMartin Matuska 	}
4681ad8388SMartin Matuska 
4781ad8388SMartin Matuska 	return i;
4881ad8388SMartin Matuska }
4981ad8388SMartin Matuska 
5081ad8388SMartin Matuska 
5181ad8388SMartin Matuska static lzma_ret
5253200025SRui Paulo powerpc_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
5381ad8388SMartin Matuska 		const lzma_filter_info *filters, bool is_encoder)
5481ad8388SMartin Matuska {
5581ad8388SMartin Matuska 	return lzma_simple_coder_init(next, allocator, filters,
5681ad8388SMartin Matuska 			&powerpc_code, 0, 4, 4, is_encoder);
5781ad8388SMartin Matuska }
5881ad8388SMartin Matuska 
5981ad8388SMartin Matuska 
6073ed8e77SXin LI #ifdef HAVE_ENCODER_POWERPC
6181ad8388SMartin Matuska extern lzma_ret
6281ad8388SMartin Matuska lzma_simple_powerpc_encoder_init(lzma_next_coder *next,
6353200025SRui Paulo 		const lzma_allocator *allocator,
6453200025SRui Paulo 		const lzma_filter_info *filters)
6581ad8388SMartin Matuska {
6681ad8388SMartin Matuska 	return powerpc_coder_init(next, allocator, filters, true);
6781ad8388SMartin Matuska }
6873ed8e77SXin LI #endif
6981ad8388SMartin Matuska 
7081ad8388SMartin Matuska 
7173ed8e77SXin LI #ifdef HAVE_DECODER_POWERPC
7281ad8388SMartin Matuska extern lzma_ret
7381ad8388SMartin Matuska lzma_simple_powerpc_decoder_init(lzma_next_coder *next,
7453200025SRui Paulo 		const lzma_allocator *allocator,
7553200025SRui Paulo 		const lzma_filter_info *filters)
7681ad8388SMartin Matuska {
7781ad8388SMartin Matuska 	return powerpc_coder_init(next, allocator, filters, false);
7881ad8388SMartin Matuska }
7973ed8e77SXin LI #endif
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