board: Introduce xenguest_arm64 board

Introduce a minimal Xen guest board running as a virtual
machine under Xen Project's hypervisor [1], [2].

Part of the code is ported from Xen mini-os and also uses
work initially done by different authors from NXP: please see
relevant files for their copyrights.

[1] https://xenbits.xen.org
[2] https://wiki.xenproject.org/

Signed-off-by: Andrii Anisov <andrii_anisov@epam.com>
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Anastasiia Lukianenko <anastasiia_lukianenko@epam.com>

include/configs/xenguest_arm64.h

@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0+
+ *
+ * (C) Copyright 2020 EPAM Systemc Inc.
+ */
+#ifndef __XENGUEST_ARM64_H
+#define __XENGUEST_ARM64_H
+
+#ifndef __ASSEMBLY__
+#include <linux/types.h>
+#endif
+
+#define CONFIG_BOARD_EARLY_INIT_F
+
+#define CONFIG_EXTRA_ENV_SETTINGS
+
+#undef CONFIG_NR_DRAM_BANKS
+#undef CONFIG_SYS_SDRAM_BASE
+
+#define CONFIG_NR_DRAM_BANKS          1
+
+/*
+ * This can be any arbitrary address as we are using PIE, but
+ * please note, that CONFIG_SYS_TEXT_BASE must match the below.
+ */
+#define CONFIG_SYS_LOAD_ADDR                    0x40000000
+#define CONFIG_LNX_KRNL_IMG_TEXT_OFFSET_BASE    CONFIG_SYS_LOAD_ADDR
+
+/* Size of malloc() pool */
+#define CONFIG_SYS_MALLOC_LEN         (32 * 1024 * 1024)
+
+/* Monitor Command Prompt */
+#define CONFIG_SYS_PROMPT_HUSH_PS2    "> "
+#define CONFIG_SYS_CBSIZE             1024
+#define CONFIG_SYS_MAXARGS            64
+#define CONFIG_SYS_BARGSIZE           CONFIG_SYS_CBSIZE
+#define CONFIG_SYS_PBSIZE             (CONFIG_SYS_CBSIZE + \
+				      sizeof(CONFIG_SYS_PROMPT) + 16)
+
+#define CONFIG_OF_SYSTEM_SETUP
+
+#define CONFIG_CMDLINE_TAG            1
+#define CONFIG_INITRD_TAG             1
+
+#endif /* __XENGUEST_ARM64_H */