1 files changed, 92 insertions, 0 deletions
diff --git a/src/drivers/vpd/vpd_decode.c b/src/drivers/vpd/vpd_decode.c
new file mode 100644
index 0000000000..0eab704ca8
--- /dev/null
+++ b/src/drivers/vpd/vpd_decode.c
@@ -0,0 +1,92 @@
+/*
+ * Copyright 2014 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * This is a copy from upstream:
+ * https://chromium.googlesource.com/chromiumos/platform/vpd/+/master/lib/vpd_decode.c
+ */
+#include "vpd_decode.h"
+
+int vpd_decode_len(
+		const u32 max_len, const u8 *in, u32 *length, u32 *decoded_len)
+{
+	u8 more;
+	int i = 0;
+
+	if (!length || !decoded_len)
+		return VPD_DECODE_FAIL;
+
+	*length = 0;
+	do {
+		if (i >= max_len)
+			return VPD_DECODE_FAIL;
+
+		more = in[i] & 0x80;
+		*length <<= 7;
+		*length |= in[i] & 0x7f;
+		++i;
+	} while (more);
+
+	*decoded_len = i;
+	return VPD_DECODE_OK;
+}
+
+int vpd_decode_string(
+		const u32 max_len, const u8 *input_buf, u32 *consumed,
+		vpd_decode_callback callback, void *callback_arg)
+{
+	int type;
+	int res;
+	u32 key_len;
+	u32 value_len;
+	u32 decoded_len;
+	const u8 *key;
+	const u8 *value;
+
+	/* type */
+	if (*consumed >= max_len)
+		return VPD_DECODE_FAIL;
+
+	type = input_buf[*consumed];
+
+	switch (type) {
+	case VPD_TYPE_INFO:
+	case VPD_TYPE_STRING:
+		(*consumed)++;
+
+		/* key */
+		res = vpd_decode_len(max_len - *consumed, &input_buf[*consumed],
+				     &key_len, &decoded_len);
+		/* key name cannot be empty, and must be followed by value. */
+		if (res != VPD_DECODE_OK || key_len < 1 ||
+		    *consumed + decoded_len + key_len >= max_len)
+			return VPD_DECODE_FAIL;
+
+		*consumed += decoded_len;
+		key = &input_buf[*consumed];
+		*consumed += key_len;
+
+		/* value */
+		res = vpd_decode_len(max_len - *consumed, &input_buf[*consumed],
+				     &value_len, &decoded_len);
+		/* value can be empty (value_len = 0). */
+		if (res != VPD_DECODE_OK ||
+		    *consumed + decoded_len + value_len > max_len)
+			return VPD_DECODE_FAIL;
+
+		*consumed += decoded_len;
+		value = &input_buf[*consumed];
+		*consumed += value_len;
+
+		if (type == VPD_TYPE_STRING)
+			return callback(key, key_len, value, value_len,
+					callback_arg);
+		break;
+
+	default:
+		return VPD_DECODE_FAIL;
+	}
+
+	return VPD_DECODE_OK;
+}