[PATCH 1/3] ArmVirtPkg/FdtClientDxe: take DT memory node 'status' property into account

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

In some cases, (e.g., when running QEMU with TrustZone emulation), the
DT may contain memory nodes whose status is set to 'secure'. Similarly,
the status may be set to 'disabled' if the consumer of the DT image is
expected to treat it as if it weren't there.

So check whether a 'status' property is present, and if so, ignore the
node if the status is not 'okay'.

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

diff --git a/ArmVirtPkg/FdtClientDxe/FdtClientDxe.c b/ArmVirtPkg/FdtClientDxe/FdtClientDxe.c
index 2d867b16fda8..fb6e0aeb9215 100644
--- a/ArmVirtPkg/FdtClientDxe/FdtClientDxe.c
+++ b/ArmVirtPkg/FdtClientDxe/FdtClientDxe.c
@@ -210,6 +210,7 @@ FindNextMemoryNodeReg (
 {
   INT32          Prev, Next;
   CONST CHAR8    *DeviceType;
+  CONST CHAR8    *NodeStatus;
   INT32          Len;
   EFI_STATUS     Status;
 
@@ -222,6 +223,13 @@ FindNextMemoryNodeReg (
       break;
     }
 
+    NodeStatus = fdt_getprop (mDeviceTreeBase, Next, "status", &Len);
+    if (NodeStatus != NULL && AsciiStrCmp (NodeStatus, "okay") != 0) {
+      DEBUG ((DEBUG_WARN, "%a: ignoring memory node with status \"%a\"\n",
+        __FUNCTION__, NodeStatus));
+      continue;
+    }
+
     DeviceType = fdt_getprop (mDeviceTreeBase, Next, "device_type", &Len);
     if (DeviceType != NULL && AsciiStrCmp (DeviceType, "memory") == 0) {
       //
-- 
2.9.3