vbe: Start a common header file

Move a few things into a new, common header file so that vbe-simple can
share code with the upcoming abrec.

Put struct simple_nvdata in it and rename it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/vbe_common.h b/boot/vbe_common.h
new file mode 100644
index 0000000..1fc70ee
--- /dev/null
+++ b/boot/vbe_common.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Verified Boot for Embedded (VBE) common functions
+ *
+ * Copyright 2024 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#ifndef __VBE_COMMON_H
+#define __VBE_COMMON_H
+
+#include <linux/types.h>
+
+struct udevice;
+
+enum {
+	MAX_VERSION_LEN		= 256,
+
+	NVD_HDR_VER_SHIFT	= 0,
+	NVD_HDR_VER_MASK	= 0xf,
+	NVD_HDR_SIZE_SHIFT	= 4,
+	NVD_HDR_SIZE_MASK	= 0xf << NVD_HDR_SIZE_SHIFT,
+
+	/* Firmware key-version is in the top 16 bits of fw_ver */
+	FWVER_KEY_SHIFT		= 16,
+	FWVER_FW_MASK		= 0xffff,
+
+	NVD_HDR_VER_CUR		= 1,	/* current version */
+};
+
+/**
+ * struct vbe_nvdata - basic storage format for non-volatile data
+ *
+ * This is used for all VBE methods
+ *
+ * @crc8: crc8 for the entire record except @crc8 field itself
+ * @hdr: header size and version (NVD_HDR_...)
+ * @spare1: unused, must be 0
+ * @fw_vernum: version and key version (FWVER_...)
+ * @flags: Flags controlling operation (enum vbe_flags)
+ */
+struct vbe_nvdata {
+	u8 crc8;
+	u8 hdr;
+	u16 spare1;
+	u32 fw_vernum;
+	u32 flags;
+	u8 spare2[0x34];
+};
+
+#endif /* __VBE_ABREC_H */