ArmVirtPkg/FdtPL011SerialPortLib: honor DT node 'status' property

In some cases, (e.g., when running QEMU with TrustZone emulation), the
DT may contain DT 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>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/ArmVirtPkg/Library/FdtPL011SerialPortLib/EarlyFdtPL011SerialPortLib.c b/ArmVirtPkg/Library/FdtPL011SerialPortLib/EarlyFdtPL011SerialPortLib.c
index c458abb..e28750f 100644
--- a/ArmVirtPkg/Library/FdtPL011SerialPortLib/EarlyFdtPL011SerialPortLib.c
+++ b/ArmVirtPkg/Library/FdtPL011SerialPortLib/EarlyFdtPL011SerialPortLib.c
@@ -66,6 +66,7 @@ SerialPortGetBaseAddress (
   INT32               Node, Prev;

   INT32               Len;

   CONST CHAR8         *Compatible;

+  CONST CHAR8         *NodeStatus;

   CONST CHAR8         *CompatibleItem;

   CONST UINT64        *RegProperty;

   UINTN               UartBase;

@@ -98,6 +99,11 @@ SerialPortGetBaseAddress (
       CompatibleItem += 1 + AsciiStrLen (CompatibleItem)) {

 

       if (AsciiStrCmp (CompatibleItem, "arm,pl011") == 0) {

+        NodeStatus = fdt_getprop (DeviceTreeBase, Node, "status", &Len);

+        if (NodeStatus != NULL && AsciiStrCmp (NodeStatus, "okay") != 0) {

+          continue;

+        }

+

         RegProperty = fdt_getprop (DeviceTreeBase, Node, "reg", &Len);

         if (Len != 16) {

           return 0;