From 3f22930b1fced27081d110ebf0d7f825ed4e07ae Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sebastien@milkymist.org>
Date: Tue, 19 Feb 2013 13:22:35 +0100
Subject: [PATCH] tools: add byteswap

---
 .gitignore       |  1 +
 tools/Makefile   |  4 ++--
 tools/byteswap.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 63 insertions(+), 2 deletions(-)
 create mode 100644 tools/byteswap.c

diff --git a/.gitignore b/.gitignore
index 378e5117..04f48b42 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,3 +8,4 @@ build/*
 tools/bin2hex
 tools/flterm
 tools/mkmmimg
+tools/byteswap
diff --git a/tools/Makefile b/tools/Makefile
index 134be463..582ed48c 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -1,5 +1,5 @@
-TARGETS=mkmmimg flterm
-CC=clang
+TARGETS=mkmmimg flterm byteswap
+CC=gcc
 
 all: $(TARGETS)
 
diff --git a/tools/byteswap.c b/tools/byteswap.c
new file mode 100644
index 00000000..8d12b632
--- /dev/null
+++ b/tools/byteswap.c
@@ -0,0 +1,60 @@
+/*
+ * Milkymist SoC
+ * Copyright (C) 2007, 2008, 2009, 2010 Sebastien Bourdeauducq
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+int main(int argc, char *argv[])
+{
+	FILE *fdi, *fdo;
+	unsigned short wi;
+	unsigned short wo;
+	int i;
+	
+	if(argc != 3) {
+		fprintf(stderr, "Usage: byteswap <infile> <outfile>\n");
+		return 1;
+	}
+	fdi = fopen(argv[1], "rb");
+	if(!fdi) {
+		perror("Unable to open input file");
+		return 1;
+	}
+	fdo = fopen(argv[2], "w");
+	if(!fdo) {
+		perror("Unable to open output file");
+		fclose(fdi);
+		return 1;
+	}
+	while(1) {
+		if(fread(&wi, 2, 1, fdi) <= 0) break;
+		wo = 0;
+		for(i=0;i<16;i++)
+			if(wi & (1 << i))
+				wo |= (0x8000 >> i);
+		/* comment out the next line on big endian machines! */
+		wo = ((wo & 0x00ff) << 8) | ((wo & 0xff00) >> 8);
+		fwrite(&wo, 2, 1, fdo);
+	}
+	fclose(fdi);
+	if(fclose(fdo) != 0) {
+		perror("Unable to close output file");
+		return 1;
+	}
+	return 0;
+}
-- 
2.30.2