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Diffstat (limited to '')
-rw-r--r-- | src/liblzma/simple/armthumb.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/src/liblzma/simple/armthumb.c b/src/liblzma/simple/armthumb.c new file mode 100644 index 0000000..25d8dbd --- /dev/null +++ b/src/liblzma/simple/armthumb.c @@ -0,0 +1,80 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file armthumb.c +/// \brief Filter for ARM-Thumb 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 +armthumb_code(void *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 += 2) { + if ((buffer[i + 1] & 0xF8) == 0xF0 + && (buffer[i + 3] & 0xF8) == 0xF8) { + uint32_t src = (((uint32_t)(buffer[i + 1]) & 7) << 19) + | ((uint32_t)(buffer[i + 0]) << 11) + | (((uint32_t)(buffer[i + 3]) & 7) << 8) + | (uint32_t)(buffer[i + 2]); + + src <<= 1; + + uint32_t dest; + if (is_encoder) + dest = now_pos + (uint32_t)(i) + 4 + src; + else + dest = src - (now_pos + (uint32_t)(i) + 4); + + dest >>= 1; + buffer[i + 1] = 0xF0 | ((dest >> 19) & 0x7); + buffer[i + 0] = (dest >> 11); + buffer[i + 3] = 0xF8 | ((dest >> 8) & 0x7); + buffer[i + 2] = (dest); + i += 2; + } + } + + return i; +} + + +static lzma_ret +armthumb_coder_init(lzma_next_coder *next, const lzma_allocator *allocator, + const lzma_filter_info *filters, bool is_encoder) +{ + return lzma_simple_coder_init(next, allocator, filters, + &armthumb_code, 0, 4, 2, is_encoder); +} + + +#ifdef HAVE_ENCODER_ARMTHUMB +extern lzma_ret +lzma_simple_armthumb_encoder_init(lzma_next_coder *next, + const lzma_allocator *allocator, + const lzma_filter_info *filters) +{ + return armthumb_coder_init(next, allocator, filters, true); +} +#endif + + +#ifdef HAVE_DECODER_ARMTHUMB +extern lzma_ret +lzma_simple_armthumb_decoder_init(lzma_next_coder *next, + const lzma_allocator *allocator, + const lzma_filter_info *filters) +{ + return armthumb_coder_init(next, allocator, filters, false); +} +#endif |