ArmVirtPkg: Move PlatformBootManagerLib to OvmfPkg

Moved the PlatformBootManagerLib to OvmfPkg and renamed to
PlatformBootManagerLibLight for easy use by other ARCH.

Build-tested only (with "ArmVirtQemu.dsc and OvmfPkgX64.dsc").

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4663

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Leif Lindholm <quic_llindhol@quicinc.com>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Lazlo Ersek <lersek@redhat.com>
Signed-off-by: Chao Li <lichao@loongson.cn>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

OvmfPkg/Library/PlatformBootManagerLibLight/PlatformBm.h

@@ -0,0 +1,45 @@
+/** @file
+  Head file for BDS Platform specific code
+
+  Copyright (C) 2015-2016, Red Hat, Inc.
+  Copyright (c) 2004 - 2008, Intel Corporation. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef _PLATFORM_BM_H_
+#define _PLATFORM_BM_H_
+
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/DevicePathLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+
+/**
+  Download the kernel, the initial ramdisk, and the kernel command line from
+  QEMU's fw_cfg. Construct a minimal SimpleFileSystem that contains the two
+  image files, and load and start the kernel from it.
+
+  The kernel will be instructed via its command line to load the initrd from
+  the same Simple FileSystem.
+
+  @retval EFI_NOT_FOUND         Kernel image was not found.
+  @retval EFI_OUT_OF_RESOURCES  Memory allocation failed.
+  @retval EFI_PROTOCOL_ERROR    Unterminated kernel command line.
+
+  @return                       Error codes from any of the underlying
+                                functions. On success, the function doesn't
+                                return.
+**/
+EFI_STATUS
+EFIAPI
+TryRunningQemuKernel (
+  VOID
+  );
+
+#endif // _PLATFORM_BM_H_