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giulcioffigiulcioffi
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Add lzss libraries in SBUBoot for decode and SBU_LoadLZSS for encode
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‎libraries/SBU/examples/SBU_LoadLZSS/lzss.cpp

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/**************************************************************************************
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INCLUDE
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**************************************************************************************/
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#include "lzss.h"
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#include <stdlib.h>
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#include <stdint.h>
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#include <MKRNB.h>
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#include <FlashStorage.h>
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/**************************************************************************************
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DEFINE
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**************************************************************************************/
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#define EI 11 /* typically 10..13 */
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#define EJ 4 /* typically 4..5 */
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#define P 1 /* If match length <= P then output one character */
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#define N (1 << EI) /* buffer size */
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#define F ((1 << EJ) + 1) /* lookahead buffer size */
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#define LZSS_EOF (-1)
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#define FPUTC_BUF_SIZE (512)
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#define FGETC_BUF_SIZE (512)
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/**************************************************************************************
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GLOBAL VARIABLES
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**************************************************************************************/
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extern NBFileUtils fileUtils;
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extern FlashClass mcu_flash;
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extern const char * UPDATE_FILE_NAME_LZSS;
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static uint32_t SKETCH_START = 0;
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static uint32_t LZSS_FILE_SIZE = 0;
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int bit_buffer = 0, bit_mask = 128;
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unsigned long codecount = 0, textcount = 0;
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unsigned char buffer[N * 2];
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static char write_buf[FPUTC_BUF_SIZE];
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static size_t write_buf_num_bytes = 0;
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static size_t bytes_written_fputc = 0;
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static size_t bytes_written_flash = 0;
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static uint32_t flash_addr = 0;
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bool fromLZSStoBIN = true;
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bool append = false;
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bool endOfFile = false;
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/**************************************************************************************
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PUBLIC FUNCTIONS
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**************************************************************************************/
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void lzss_init(uint32_t const sketch_start, bool LZSStoBIN)
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{
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fromLZSStoBIN = LZSStoBIN;
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if (LZSStoBIN) {
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SKETCH_START = sketch_start;
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flash_addr = sketch_start;
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LZSS_FILE_SIZE = fileUtils.listFile("UPDATE.BIN.LZSS");
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}
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}
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void lzss_flush()
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{
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bytes_written_fputc += write_buf_num_bytes;
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if (fromLZSStoBIN) {
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/* Only write to the flash once we've surpassed
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* the SBU in the update binary.
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*/
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if (bytes_written_fputc > (SKETCH_START - 0x2000))
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{
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mcu_flash.write((void*)flash_addr, write_buf, write_buf_num_bytes);
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flash_addr += write_buf_num_bytes;
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}
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} else {
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fileUtils.downloadFile("UPDATE.BIN.LZSS", write_buf, write_buf_num_bytes, append);
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append = true;
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}
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write_buf_num_bytes = 0;
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}
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/**************************************************************************************
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PRIVATE FUNCTIONS
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**************************************************************************************/
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void lzss_fputc(int const c)
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{
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/* Buffer the decompressed data into a buffer so
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* we can perform block writes and don't need to
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* write every byte singly on the flash (which
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* wouldn't be possible anyway).
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*/
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write_buf[write_buf_num_bytes] = static_cast<char>(c);
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write_buf_num_bytes++;
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/* The write buffer is full of decompressed
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* data, write it to the flash now.
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*/
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if (write_buf_num_bytes == FPUTC_BUF_SIZE || endOfFile)
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lzss_flush();
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}
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/**************************************************************************************
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LZSS FUNCTIONS
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**************************************************************************************/
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void putbit1(void)
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{
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bit_buffer |= bit_mask;
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if ((bit_mask >>= 1) == 0) {
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lzss_fputc(bit_buffer);
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bit_buffer = 0; bit_mask = 128;
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}
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}
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void putbit0(void)
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{
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if ((bit_mask >>= 1) == 0) {
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lzss_fputc(bit_buffer);
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bit_buffer = 0; bit_mask = 128;
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}
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}
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void flush_bit_buffer(void)
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{
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if (bit_mask != 128) {
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//if (fputc(bit_buffer, outfile) == EOF) error();
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lzss_fputc(bit_buffer);
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codecount++;
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}
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}
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void output1(int c)
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{
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int mask;
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putbit1();
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mask = 256;
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while (mask >>= 1) {
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if (c & mask) putbit1();
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else putbit0();
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}
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}
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void output2(int x, int y)
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{
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int mask;
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putbit0();
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mask = N;
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while (mask >>= 1) {
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if (x & mask) putbit1();
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else putbit0();
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}
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mask = (1 << EJ);
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while (mask >>= 1) {
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if (y & mask) putbit1();
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else putbit0();
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}
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}
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int lzss_encode(const char buf_in[], uint32_t size)
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{
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int i, j, f1, x, y, r, s, bufferend, c;
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for (i = 0; i < N - F; i++) buffer[i] = ' ';
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for (i = N - F; i < N * 2; i++) {
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if (textcount >= size) {
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endOfFile = true;
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break;
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} else {
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buffer[i] = buf_in[textcount];
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textcount++;
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}
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}
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bufferend = i; r = N - F; s = 0;
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while (r < bufferend) {
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f1 = (F <= bufferend - r) ? F : bufferend - r;
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x = 0; y = 1; c = buffer[r];
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for (i = r - 1; i >= s; i--)
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if (buffer[i] == c) {
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for (j = 1; j < f1; j++)
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if (buffer[i + j] != buffer[r + j]) break;
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if (j > y) {
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x = i; y = j;
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}
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}
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if (y <= P) { y = 1; output1(c); }
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else output2(x & (N - 1), y - 2);
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r += y; s += y;
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if (r >= N * 2 - F) {
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for (i = 0; i < N; i++) buffer[i] = buffer[i + N];
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bufferend -= N; r -= N; s -= N;
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while (bufferend < N * 2) {
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if (textcount >= size) {
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endOfFile = true;
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break;
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} else {
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buffer[bufferend++] = buf_in[textcount];
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textcount++;
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}
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}
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}
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}
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flush_bit_buffer();
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return bytes_written_fputc;
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}

‎libraries/SBU/examples/SBU_LoadLZSS/lzss.h

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#ifndef SBU_LZSS_H_
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#define SBU_LZSS_H_
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/**************************************************************************************
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INCLUDE
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**************************************************************************************/
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#include <stdint.h>
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/**************************************************************************************
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FUNCTION DEFINITION
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**************************************************************************************/
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void lzss_init(uint32_t const sketch_start, bool LZSStoBIN);
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void lzss_flush();
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int lzss_encode(const char buf_in[], uint32_t size);
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#endif /* SBU_LZSS_H_ */

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