[PATCH 1/2] ArmPlatformPkg/NorFlashDxe: use one GUID plus index to identify flash banks

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

Currently, each flash bank controlled by ArmPlatformPkg/NorFlashDxe
has its own VendorHw GUID, and instances of NorFlashPlatformLib
describe each bank to the driver, along with the GUID for each.

This works ok for bare metal platforms, but it would be useful for
virtual platforms if we could obtain this information from a
device tree, which would require us to invent GUIDs on the fly,
given that the 'cfi-flash' binding does not include a GUID.

So instead, let's switch to a single GUID for all flash banks,
and update the driver's device path handling to include an index
to identify each bank uniquely.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashDxe.c | 15 +++++++++------
 ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashDxe.h |  3 +++
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashDxe.c b/ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashDxe.c
index 46e815beb343..60a06e4a5058 100644
--- a/ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashDxe.c
+++ b/ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashDxe.c
@@ -82,10 +82,14 @@ NOR_FLASH_INSTANCE  mNorFlashInstanceTemplate = {
       {
         HARDWARE_DEVICE_PATH,
         HW_VENDOR_DP,
-        { (UINT8)sizeof(VENDOR_DEVICE_PATH), (UINT8)((sizeof(VENDOR_DEVICE_PATH)) >> 8) }
+        {
+          (UINT8)(OFFSET_OF(NOR_FLASH_DEVICE_PATH, End)),
+          (UINT8)(OFFSET_OF(NOR_FLASH_DEVICE_PATH, End) >> 8)
+        }
       },
       { 0x0, 0x0, 0x0, { 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0 } }, // GUID ... NEED TO BE FILLED
     },
+    0, // Index
     {
       END_DEVICE_PATH_TYPE,
       END_ENTIRE_DEVICE_PATH_SUBTYPE,
@@ -99,10 +103,9 @@ NorFlashCreateInstance (
   IN UINTN                  NorFlashDeviceBase,
   IN UINTN                  NorFlashRegionBase,
   IN UINTN                  NorFlashSize,
-  IN UINT32                 MediaId,
+  IN UINT32                 Index,
   IN UINT32                 BlockSize,
   IN BOOLEAN                SupportFvb,
-  IN CONST GUID             *NorFlashGuid,
   OUT NOR_FLASH_INSTANCE**  NorFlashInstance
   )
 {
@@ -121,11 +124,12 @@ NorFlashCreateInstance (
   Instance->Size = NorFlashSize;
 
   Instance->BlockIoProtocol.Media = &Instance->Media;
-  Instance->Media.MediaId = MediaId;
+  Instance->Media.MediaId = Index;
   Instance->Media.BlockSize = BlockSize;
   Instance->Media.LastBlock = (NorFlashSize / BlockSize)-1;
 
-  CopyGuid (&Instance->DevicePath.Vendor.Guid, NorFlashGuid);
+  CopyGuid (&Instance->DevicePath.Vendor.Guid, &gEfiCallerIdGuid);
+  Instance->DevicePath.Index = Index;
 
   Instance->ShadowBuffer = AllocateRuntimePool (BlockSize);;
   if (Instance->ShadowBuffer == NULL) {
@@ -1311,7 +1315,6 @@ NorFlashInitialise (
       Index,
       NorFlashDevices[Index].BlockSize,
       ContainVariableStorage,
-      &NorFlashDevices[Index].Guid,
       &mNorFlashInstances[Index]
     );
     if (EFI_ERROR(Status)) {
diff --git a/ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashDxe.h b/ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashDxe.h
index 5c07694fbfaa..8886aa43d9f3 100644
--- a/ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashDxe.h
+++ b/ArmPlatformPkg/Drivers/NorFlashDxe/NorFlashDxe.h
@@ -122,10 +122,13 @@
 
 typedef struct _NOR_FLASH_INSTANCE                NOR_FLASH_INSTANCE;
 
+#pragma pack(1)
 typedef struct {
   VENDOR_DEVICE_PATH                  Vendor;
+  UINT8                               Index;
   EFI_DEVICE_PATH_PROTOCOL            End;
 } NOR_FLASH_DEVICE_PATH;
+#pragma pack()
 
 struct _NOR_FLASH_INSTANCE {
   UINT32                              Signature;
-- 
2.17.1