src/system/mtdutils: Add files from mtd-utils

- based on mtd-utils http://git.infradead.org/mtd-utils.git commit ab8c6fb93ce9db0f09401c4b819b0b277dc00340 (2013-07-01) - Add files for create jffs2 image and using sumtool - Creating classes for mkfs.jffs2 and sumtool Origin commit data ------------------ Commit: d8957d17ac Author: Michael Liebmann <tuxcode.bbg@gmail.com> Date: 2013-09-01 (Sun, 01 Sep 2013) Origin message was: ------------------ src/system/mtdutils: Add files from mtd-utils - based on mtd-utils http://git.infradead.org/mtd-utils.git commit ab8c6fb93ce9db0f09401c4b819b0b277dc00340 (2013-07-01) - Add files for create jffs2 image and using sumtool - Creating classes for mkfs.jffs2 and sumtool
2025-09-01 01:41:12 +02:00 · 2013-09-01 17:57:41 +02:00
parent 1a4b568ceb
commit d87eeae5ce
33 changed files with 9672 additions and 0 deletions
--- a/src/system/mtdutils/compr_rtime.cpp
+++ b/src/system/mtdutils/compr_rtime.cpp
@@ -0,0 +1,124 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright (C) 2001-2003 Red Hat, Inc.
+ *
+ * Created by Arjan van de Ven <arjanv@redhat.com>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ * Very simple lz77-ish encoder.
+ *
+ * Theory of operation: Both encoder and decoder have a list of "last
+ * occurrences" for every possible source-value; after sending the
+ * first source-byte, the second byte indicated the "run" length of
+ * matches
+ *
+ * The algorithm is intended to only send "whole bytes", no bit-messing.
+ *
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include "compr.h"
+
+/* _compress returns the compressed size, -1 if bigger */
+static int jffs2_rtime_compress(unsigned char *data_in, unsigned char *cpage_out,
+		uint32_t *sourcelen, uint32_t *dstlen)
+{
+	short positions[256];
+	int outpos = 0;
+	int pos=0;
+
+	memset(positions,0,sizeof(positions));
+
+	while (pos < (*sourcelen) && outpos+2 <= (*dstlen)) {
+		int backpos, runlen=0;
+		unsigned char value;
+
+		value = data_in[pos];
+
+		cpage_out[outpos++] = data_in[pos++];
+
+		backpos = positions[value];
+		positions[value]=pos;
+
+		while ((backpos < pos) && (pos < (*sourcelen)) &&
+				(data_in[pos]==data_in[backpos++]) && (runlen<255)) {
+			pos++;
+			runlen++;
+		}
+		cpage_out[outpos++] = runlen;
+	}
+
+	if (outpos >= pos) {
+		/* We failed */
+		return -1;
+	}
+
+	/* Tell the caller how much we managed to compress, and how much space it took */
+	*sourcelen = pos;
+	*dstlen = outpos;
+	return 0;
+}
+
+
+static int jffs2_rtime_decompress(unsigned char *data_in, unsigned char *cpage_out,
+		__attribute__((unused)) uint32_t srclen, uint32_t destlen)
+{
+	short positions[256];
+	uint32_t outpos = 0;
+	int pos=0;
+
+	memset(positions,0,sizeof(positions));
+
+	while (outpos<destlen) {
+		unsigned char value;
+		uint32_t backoffs;
+		uint32_t repeat;
+
+		value = data_in[pos++];
+		cpage_out[outpos++] = value; /* first the verbatim copied byte */
+		repeat = data_in[pos++];
+		backoffs = positions[value];
+
+		positions[value]=outpos;
+		if (repeat) {
+			if (backoffs + repeat >= outpos) {
+				while(repeat) {
+					cpage_out[outpos++] = cpage_out[backoffs++];
+					repeat--;
+				}
+			} else {
+				memcpy(&cpage_out[outpos],&cpage_out[backoffs],repeat);
+				outpos+=repeat;
+			}
+		}
+	}
+	return 0;
+}
+
+static struct jffs2_compressor jffs2_rtime_comp;
+void fill_jffs2_rtime_compressor_struct();
+
+void fill_jffs2_rtime_compressor_struct()
+{
+	jffs2_rtime_comp.priority 	= JFFS2_RTIME_PRIORITY;
+	jffs2_rtime_comp.name 		= "rtime";
+	jffs2_rtime_comp.disabled 	= 0;
+	jffs2_rtime_comp.compr 		= JFFS2_COMPR_RTIME;
+	jffs2_rtime_comp.compress 	= &jffs2_rtime_compress;
+	jffs2_rtime_comp.decompress	= &jffs2_rtime_decompress;
+}
+
+int jffs2_rtime_init(void)
+{
+	fill_jffs2_rtime_compressor_struct();
+	return jffs2_register_compressor(&jffs2_rtime_comp);
+}
+
+void jffs2_rtime_exit(void)
+{
+	fill_jffs2_rtime_compressor_struct();
+	jffs2_unregister_compressor(&jffs2_rtime_comp);
+}