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powerpc.c
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powerpc.c
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///////////////////////////////////////////////////////////////////////////////
//
/// \file powerpc.c
/// \brief Filter for PowerPC (big endian) binaries
///
// Authors: Igor Pavlov
// Lasse Collin
//
// This file has been put into the public domain.
// You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////
#include "simple_private.h"
static size_t
powerpc_code(lzma_simple *simple lzma_attribute((unused)),
uint32_t now_pos, bool is_encoder,
uint8_t *buffer, size_t size)
{
size_t i;
for (i = 0; i + 4 <= size; i += 4) {
// PowerPC branch 6(48) 24(Offset) 1(Abs) 1(Link)
if ((buffer[i] >> 2) == 0x12
&& ((buffer[i + 3] & 3) == 1)) {
const uint32_t src = ((buffer[i + 0] & 3) << 24)
| (buffer[i + 1] << 16)
| (buffer[i + 2] << 8)
| (buffer[i + 3] & (~3));
uint32_t dest;
if (is_encoder)
dest = now_pos + (uint32_t)(i) + src;
else
dest = src - (now_pos + (uint32_t)(i));
buffer[i + 0] = 0x48 | ((dest >> 24) & 0x03);
buffer[i + 1] = (dest >> 16);
buffer[i + 2] = (dest >> 8);
buffer[i + 3] &= 0x03;
buffer[i + 3] |= dest;
}
}
return i;
}
static lzma_ret
powerpc_coder_init(lzma_next_coder *next, lzma_allocator *allocator,
const lzma_filter_info *filters, bool is_encoder)
{
return lzma_simple_coder_init(next, allocator, filters,
&powerpc_code, 0, 4, 4, is_encoder);
}
extern lzma_ret
lzma_simple_powerpc_encoder_init(lzma_next_coder *next,
lzma_allocator *allocator, const lzma_filter_info *filters)
{
return powerpc_coder_init(next, allocator, filters, true);
}
extern lzma_ret
lzma_simple_powerpc_decoder_init(lzma_next_coder *next,
lzma_allocator *allocator, const lzma_filter_info *filters)
{
return powerpc_coder_init(next, allocator, filters, false);
}