ar71xx: add library code for RLE decoding

It will be used for the MikroTik boards. SVN-Revision: 33337
12 years ago · 73df240bb3
parent f4be8a76de
commit 73df240bb3
2 changed files with 115 additions and 0 deletions
--- a/target/linux/ar71xx/config-3.3
+++ b/target/linux/ar71xx/config-3.3
@ -188,6 +188,7 @@ CONFIG_PCI_DOMAINS=y
 CONFIG_PERF_USE_VMALLOC=y
 CONFIG_PHYLIB=y
 # CONFIG_PREEMPT_RCU is not set
+# CONFIG_RLE_DECOMPRESS is not set
 CONFIG_RTL8306_PHY=y
 CONFIG_RTL8366RB_PHY=y
 CONFIG_RTL8366S_PHY=y
--- a/target/linux/ar71xx/patches-3.3/310-lib-add-rle-decompression.patch
+++ b/target/linux/ar71xx/patches-3.3/310-lib-add-rle-decompression.patch
@ -0,0 +1,114 @@
+--- a/lib/Kconfig
+++ b/lib/Kconfig
+@@ -124,6 +124,9 @@ config LZMA_COMPRESS
+ config LZMA_DECOMPRESS
+     tristate
+ 
+config RLE_DECOMPRESS
+	tristate
+
+ #
+ # These all provide a common interface (hence the apparent duplication with
+ # ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
+--- a/lib/Makefile
+++ b/lib/Makefile
+@@ -85,6 +85,7 @@ obj-$(CONFIG_XZ_DEC) += xz/
+ obj-$(CONFIG_RAID6_PQ) += raid6/
+ obj-$(CONFIG_LZMA_COMPRESS) += lzma/
+ obj-$(CONFIG_LZMA_DECOMPRESS) += lzma/
+obj-$(CONFIG_RLE_DECOMPRESS) += rle.o
+ 
+ lib-$(CONFIG_DECOMPRESS_GZIP) += decompress_inflate.o
+ lib-$(CONFIG_DECOMPRESS_BZIP2) += decompress_bunzip2.o
+--- /dev/null
+++ b/include/linux/rle.h
+@@ -0,0 +1,8 @@
+#ifndef _RLE_H_
+#define _RLE_H_
+
+int rle_decode(const unsigned char *src, size_t srclen,
+	       unsigned char *dst, size_t dstlen,
+	       size_t *src_done, size_t *dst_done);
+
+#endif /* _RLE_H_ */
+--- /dev/null
+++ b/lib/rle.c
+@@ -0,0 +1,78 @@
+/*
+ *  RLE decoding routine
+ *
+ *  Copyright (C) 2012 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rle.h>
+
+int rle_decode(const unsigned char *src, size_t srclen,
+	       unsigned char *dst, size_t dstlen,
+	       size_t *src_done, size_t *dst_done)
+{
+	size_t srcpos, dstpos;
+	int ret;
+
+	srcpos = 0;
+	dstpos = 0;
+	ret = -EINVAL;
+
+	/* sanity checks */
+	if (!src || !srclen || !dst || !dstlen)
+		goto out;
+
+	while (1) {
+		char count;
+
+		if (srcpos >= srclen)
+			break;
+
+		count = (char) src[srcpos++];
+		if (count == 0) {
+			ret = 0;
+			break;
+		}
+
+		if (count > 0) {
+			unsigned char c;
+
+			if (srcpos >= srclen)
+				break;
+
+			c = src[srcpos++];
+
+			while (count--) {
+				if (dstpos >= dstlen)
+					break;
+
+				dst[dstpos++] = c;
+			}
+		} else {
+			count *= -1;
+
+			while (count--) {
+				if (srcpos >= srclen)
+					break;
+				if (dstpos >= dstlen)
+					break;
+				dst[dstpos++] = src[srcpos++];
+			}
+		}
+	}
+
+out:
+	if (src_done)
+		*src_done = srcpos;
+	if (dst_done)
+		*dst_done = dstpos;
+
+	return ret;
+}
+
+EXPORT_SYMBOL_GPL(rle_decode);