[PATCH 2/3] ArmVirtPkg/FdtClientDxe: install DT configuration table at ReadyToBoot

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

Wait for ReadyToBoot to install the FDT configuration table. This allows
any driver to make modifications in the mean time, and will also allow us
to defer the decision of whether to install it in the first place to later
on in the boot.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 ArmVirtPkg/FdtClientDxe/FdtClientDxe.c   | 41 ++++++++++++++++----
 ArmVirtPkg/FdtClientDxe/FdtClientDxe.inf |  1 +
 2 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/ArmVirtPkg/FdtClientDxe/FdtClientDxe.c b/ArmVirtPkg/FdtClientDxe/FdtClientDxe.c
index 7cc0c44ca12a..0327af5739f2 100644
--- a/ArmVirtPkg/FdtClientDxe/FdtClientDxe.c
+++ b/ArmVirtPkg/FdtClientDxe/FdtClientDxe.c
@@ -303,6 +303,30 @@ STATIC FDT_CLIENT_PROTOCOL mFdtClientProtocol = {
   GetOrInsertChosenNode,
 };
 
+STATIC
+VOID
+EFIAPI
+OnReadyToBoot (
+  EFI_EVENT       Event,
+  VOID            *Context
+  )
+{
+  EFI_STATUS      Status;
+
+  if (!FeaturePcdGet (PcdPureAcpiBoot)) {
+    //
+    // Only install the FDT as a configuration table if we want to leave it up
+    // to the OS to decide whether it prefers ACPI over DT.
+    //
+    Status = gBS->InstallConfigurationTable (&gFdtTableGuid, mDeviceTreeBase);
+    ASSERT_EFI_ERROR (Status);
+  }
+
+  gBS->CloseEvent (Event);
+}
+
+STATIC EFI_EVENT         ReadyToBootEvent;
+
 EFI_STATUS
 EFIAPI
 InitializeFdtClientDxe (
@@ -330,14 +354,15 @@ InitializeFdtClientDxe (
 
   DEBUG ((EFI_D_INFO, "%a: DTB @ 0x%p\n", __FUNCTION__, mDeviceTreeBase));
 
-  if (!FeaturePcdGet (PcdPureAcpiBoot)) {
-    //
-    // Only install the FDT as a configuration table if we want to leave it up
-    // to the OS to decide whether it prefers ACPI over DT.
-    //
-    Status = gBS->InstallConfigurationTable (&gFdtTableGuid, DeviceTreeBase);
-    ASSERT_EFI_ERROR (Status);
-  }
+  Status = gBS->CreateEventEx (
+                  EVT_NOTIFY_SIGNAL,
+                  TPL_CALLBACK,
+                  OnReadyToBoot,
+                  NULL,
+                  &gEfiEventReadyToBootGuid,
+                  &ReadyToBootEvent
+                  );
+  ASSERT_EFI_ERROR (Status);
 
   return gBS->InstallProtocolInterface (&ImageHandle, &gFdtClientProtocolGuid,
                 EFI_NATIVE_INTERFACE, &mFdtClientProtocol);
diff --git a/ArmVirtPkg/FdtClientDxe/FdtClientDxe.inf b/ArmVirtPkg/FdtClientDxe/FdtClientDxe.inf
index 3a0cd37040eb..00017727c32c 100644
--- a/ArmVirtPkg/FdtClientDxe/FdtClientDxe.inf
+++ b/ArmVirtPkg/FdtClientDxe/FdtClientDxe.inf
@@ -42,6 +42,7 @@ [Protocols]
   gFdtClientProtocolGuid                  ## PRODUCES
 
 [Guids]
+  gEfiEventReadyToBootGuid
   gFdtHobGuid
   gFdtTableGuid
 
-- 
2.7.4