From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date: Fri, 30 Nov 2018 11:28:28 +0000 (+0100)
Subject: ArmVirtPkg/NorFlashQemuLib: disregard our primary FV
X-Git-Tag: edk2-stable201903~530
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=5e27deed438b9d74a6b08bde85f1c23f007e01c0

ArmVirtPkg/NorFlashQemuLib: disregard our primary FV

The primary FV contains the firmware boot image, which is not
runtime updatable in our case. So exposing it to the NOR flash
driver is undesirable, since it may attempt to modify the NOR
flash contents. It is also rather pointless, since we don't
keep anything there that we care to expose. (the SEC and PEI
phase modules are not executable from DXE context, and the
contents of the embedded DXE phase FV are exposed by the DXE
core directly via the FVB2 protocol)

So let's disregard the NOR flash block that covers the primary
FV.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---

diff --git a/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.c b/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.c
index 2678f57eaa..d238e39a59 100644
--- a/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.c
+++ b/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.c
@@ -75,13 +75,22 @@ NorFlashPlatformGetDevices (
       Size = SwapBytes64 (ReadUnaligned64 ((VOID *)&Reg[2]));
       Reg += 4;
 
+      PropSize -= 4 * sizeof (UINT32);
+
+      //
+      // Disregard any flash devices that overlap with the primary FV.
+      // The firmware is not updatable from inside the guest anyway.
+      //
+      if ((PcdGet64 (PcdFvBaseAddress) + PcdGet32 (PcdFvSize) > Base) &&
+          (Base + Size) > PcdGet64 (PcdFvBaseAddress)) {
+        continue;
+      }
+
       mNorFlashDevices[Num].DeviceBaseAddress = (UINTN)Base;
       mNorFlashDevices[Num].RegionBaseAddress = (UINTN)Base;
       mNorFlashDevices[Num].Size              = (UINTN)Size;
       mNorFlashDevices[Num].BlockSize         = QEMU_NOR_BLOCK_SIZE;
       Num++;
-
-      PropSize -= 4 * sizeof (UINT32);
     }
   }
 
diff --git a/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.inf b/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.inf
index d86ff36dbd..c5752a243e 100644
--- a/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.inf
+++ b/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.inf
@@ -28,6 +28,7 @@
 [Packages]
   MdePkg/MdePkg.dec
   ArmPlatformPkg/ArmPlatformPkg.dec
+  ArmPkg/ArmPkg.dec
   ArmVirtPkg/ArmVirtPkg.dec
 
 [LibraryClasses]
@@ -40,3 +41,7 @@
 
 [Depex]
   gFdtClientProtocolGuid
+
+[Pcd]
+  gArmTokenSpaceGuid.PcdFvBaseAddress
+  gArmTokenSpaceGuid.PcdFvSize