1 files changed, 127 insertions, 0 deletions
diff --git a/sys/boot/arm/at91/libat91/xmodem.c b/sys/boot/arm/at91/libat91/xmodem.c
new file mode 100644
index 0000000..c3903aa
--- /dev/null
+++ b/sys/boot/arm/at91/libat91/xmodem.c
@@ -0,0 +1,127 @@
+/*-
+ * Copyright (c) 2006 M. Warner Losh.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software is derived from software provide by Kwikbyte who specifically
+ * disclaimed copyright on the code.  This version of xmodem has been nearly
+ * completely rewritten, but the CRC is from the original.
+ *
+ * $FreeBSD$
+ */
+
+#include "lib.h"
+
+#define PACKET_SIZE	128
+
+/* Line control codes */
+#define SOH			0x01	/* start of header */
+#define ACK			0x06	/* Acknowledge */
+#define NAK			0x15	/* Negative acknowledge */
+#define CAN			0x18	/* Cancel */
+#define EOT			0x04	/* end of text */
+
+/*
+ * int GetRecord(char , char *)
+ *  This private function receives a x-modem record to the pointer and
+ * returns non-zero on success.
+ */
+static int
+GetRecord(char blocknum, char *dest)
+{
+	int		size;
+	int		ch;
+	unsigned	chk, j;
+
+	chk = 0;
+
+	if ((ch = getc(1)) == -1)
+		goto err;
+	if (ch != blocknum)
+		goto err;
+	if ((ch = getc(1)) == -1)
+		goto err;
+	if (ch != (~blocknum & 0xff))
+		goto err;
+	
+	for (size = 0; size < PACKET_SIZE; ++size) {
+		if ((ch = getc(1)) == -1)
+			goto err;
+		chk = chk ^ ch << 8;
+		for (j = 0; j < 8; ++j) {
+			if (chk & 0x8000)
+				chk = chk << 1 ^ 0x1021;
+			else
+				chk = chk << 1;
+		}
+		*dest++ = ch;
+	}
+
+	chk &= 0xFFFF;
+
+	if (((ch = getc(1)) == -1) || ((ch & 0xff) != ((chk >> 8) & 0xFF)))
+	    goto err;
+	if (((ch = getc(1)) == -1) || ((ch & 0xff) != (chk & 0xFF)))
+	    goto err;
+	putchar(ACK);
+
+	return (1);
+err:;
+	putchar(CAN);
+	// We should allow for resend, but we don't.
+	return (0);
+}
+
+/*
+ * int xmodem_rx(char *)
+ *  This global function receives a x-modem transmission consisting of
+ * (potentially) several blocks.  Returns the number of bytes received or
+ * -1 on error.
+ */
+int
+xmodem_rx(char *dest)
+{
+	int		starting, ch;
+	char		packetNumber, *startAddress = dest;
+
+	packetNumber = 1;
+	starting = 1;
+
+	while (1) {
+		if (starting)
+			putchar('C');
+		if (((ch = getc(1)) == -1) || (ch != SOH && ch != EOT))
+			continue;
+		if (ch == EOT) {
+			putchar(ACK);
+			return (dest - startAddress);
+		}
+		starting = 0;
+		// Xmodem packets: SOH PKT# ~PKT# 128-bytes CRC16
+		if (!GetRecord(packetNumber, dest))
+			return (-1);
+		dest += PACKET_SIZE;
+		packetNumber++;
+	}
+
+	// the loop above should return in all cases
+	return (-1);
+}