[PATCH 03/13] OvmfPkg: introduce QemuLoadImageLib library class

["Ard Biesheuvel" <ard.biesheuvel@linaro.org>]

Introduce the QemuLoadImageLib library class that we will instantiate
to load the kernel image passed via the QEMU command line using the
standard LoadImage boot service.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2566
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 OvmfPkg/Include/Library/QemuLoadImageLib.h | 78 ++++++++++++++++++++
 OvmfPkg/OvmfPkg.dec                        |  5 ++
 2 files changed, 83 insertions(+)

diff --git a/OvmfPkg/Include/Library/QemuLoadImageLib.h b/OvmfPkg/Include/Library/QemuLoadImageLib.h
new file mode 100644
index 000000000000..304853096593
--- /dev/null
+++ b/OvmfPkg/Include/Library/QemuLoadImageLib.h
@@ -0,0 +1,78 @@
+/** @file
+  Load a kernel image and command line passed to QEMU via
+  the command line
+
+  Copyright (C) 2020, Arm, Limited.
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#ifndef QEMU_LOAD_IMAGE_LIB_H__
+#define QEMU_LOAD_IMAGE_LIB_H__
+
+#include <Uefi/UefiBaseType.h>
+#include <Base.h>
+
+#include <Protocol/LoadedImage.h>
+
+/**
+  Download the kernel, the initial ramdisk, and the kernel command line from
+  QEMU's fw_cfg. The kernel will be instructed via its command line to load
+  the initrd from the same Simple FileSystem.
+
+  @param[out] ImageHandle       The image handle that was allocated for
+                                loading the image
+
+  @retval EFI_SUCCESS           The image was loaded successfully.
+  @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.
+**/
+EFI_STATUS
+EFIAPI
+QemuLoadKernelImage (
+  OUT EFI_HANDLE          *ImageHandle
+  );
+
+/**
+  Transfer control to a kernel image loaded with QemuLoadKernelImage ()
+
+  @param[in]  ImageHandle         Handle of image to be started.
+
+  @retval EFI_INVALID_PARAMETER   ImageHandle is either an invalid image handle
+                                  or the image has already been initialized with
+                                  StartImage
+  @retval EFI_SECURITY_VIOLATION  The current platform policy specifies that the
+                                  image should not be started.
+
+  @return                         Error codes returned by the started image.
+                                  On success, the function doesn't return.
+**/
+EFI_STATUS
+EFIAPI
+QemuStartKernelImage (
+  IN  EFI_HANDLE          ImageHandle
+  );
+
+/**
+  Unloads an image loaded with QemuLoadKernelImage ().
+
+  @param  ImageHandle             Handle that identifies the image to be
+                                  unloaded.
+
+  @retval EFI_SUCCESS             The image has been unloaded.
+  @retval EFI_UNSUPPORTED         The image has been started, and does not
+                                  support unload.
+  @retval EFI_INVALID_PARAMETER   ImageHandle is not a valid image handle.
+
+**/
+EFI_STATUS
+EFIAPI
+QemuUnloadKernelImage (
+  IN  EFI_HANDLE          ImageHandle
+  );
+
+#endif
diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
index d88778600517..26f977bad795 100644
--- a/OvmfPkg/OvmfPkg.dec
+++ b/OvmfPkg/OvmfPkg.dec
@@ -58,6 +58,11 @@ [LibraryClasses]
   #
   QemuBootOrderLib|Include/Library/QemuBootOrderLib.h
 
+  ##  @libraryclass  Load a kernel image and command line passed to QEMU via
+  #                  the command line
+  #
+  QemuLoadImageLib|Include/Library/QemuLoadImageLib.h
+
   ##  @libraryclass  Serialize (and deserialize) variables
   #
   SerializeVariablesLib|Include/Library/SerializeVariablesLib.h
-- 
2.17.1