ArmVirtPkg/NorFlashQemuLib: disable NOR flash DT nodes upon discovery

[mirror_edk2.git] / ArmVirtPkg / Library / NorFlashQemuLib / NorFlashQemuLib.c

/** @file\r
\r
 Copyright (c) 2014-2018, Linaro Ltd. All rights reserved.<BR>\r
\r
 SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
 **/\r
\r
#include <Library/BaseLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/NorFlashPlatformLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
\r
#include <Protocol/FdtClient.h>\r
\r
#define QEMU_NOR_BLOCK_SIZE    SIZE_256KB\r
\r
#define MAX_FLASH_BANKS        4\r
\r
EFI_STATUS\r
NorFlashPlatformInitialization (\r
  VOID\r
  )\r
{\r
  return EFI_SUCCESS;\r
}\r
\r
NOR_FLASH_DESCRIPTION mNorFlashDevices[MAX_FLASH_BANKS];\r
\r
EFI_STATUS\r
NorFlashPlatformGetDevices (\r
  OUT NOR_FLASH_DESCRIPTION   **NorFlashDescriptions,\r
  OUT UINT32                  *Count\r
  )\r
{\r
  FDT_CLIENT_PROTOCOL         *FdtClient;\r
  INT32                       Node;\r
  EFI_STATUS                  Status;\r
  EFI_STATUS                  FindNodeStatus;\r
  CONST UINT32                *Reg;\r
  UINT32                      PropSize;\r
  UINT32                      Num;\r
  UINT64                      Base;\r
  UINT64                      Size;\r
\r
  Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,\r
                  (VOID **)&FdtClient);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  Num = 0;\r
  for (FindNodeStatus = FdtClient->FindCompatibleNode (FdtClient,\r
                                     "cfi-flash", &Node);\r
       !EFI_ERROR (FindNodeStatus) && Num < MAX_FLASH_BANKS;\r
       FindNodeStatus = FdtClient->FindNextCompatibleNode (FdtClient,\r
                                     "cfi-flash", Node, &Node)) {\r
\r
    Status = FdtClient->GetNodeProperty (FdtClient, Node, "reg",\r
                          (CONST VOID **)&Reg, &PropSize);\r
    if (EFI_ERROR (Status)) {\r
      DEBUG ((DEBUG_ERROR, "%a: GetNodeProperty () failed (Status == %r)\n",\r
        __FUNCTION__, Status));\r
      continue;\r
    }\r
\r
    ASSERT ((PropSize % (4 * sizeof (UINT32))) == 0);\r
\r
    while (PropSize >= (4 * sizeof (UINT32)) && Num < MAX_FLASH_BANKS) {\r
      Base = SwapBytes64 (ReadUnaligned64 ((VOID *)&Reg[0]));\r
      Size = SwapBytes64 (ReadUnaligned64 ((VOID *)&Reg[2]));\r
      Reg += 4;\r
\r
      PropSize -= 4 * sizeof (UINT32);\r
\r
      //\r
      // Disregard any flash devices that overlap with the primary FV.\r
      // The firmware is not updatable from inside the guest anyway.\r
      //\r
      if ((PcdGet64 (PcdFvBaseAddress) + PcdGet32 (PcdFvSize) > Base) &&\r
          (Base + Size) > PcdGet64 (PcdFvBaseAddress)) {\r
        continue;\r
      }\r
\r
      mNorFlashDevices[Num].DeviceBaseAddress = (UINTN)Base;\r
      mNorFlashDevices[Num].RegionBaseAddress = (UINTN)Base;\r
      mNorFlashDevices[Num].Size              = (UINTN)Size;\r
      mNorFlashDevices[Num].BlockSize         = QEMU_NOR_BLOCK_SIZE;\r
      Num++;\r
    }\r
\r
    //\r
    // UEFI takes ownership of the NOR flash, and exposes its functionality\r
    // through the UEFI Runtime Services GetVariable, SetVariable, etc. This\r
    // means we need to disable it in the device tree to prevent the OS from\r
    // attaching its device driver as well.\r
    // Note that this also hides other flash banks, but the only other flash\r
    // bank we expect to encounter is the one that carries the UEFI executable\r
    // code, which is not intended to be guest updatable, and is usually backed\r
    // in a readonly manner by QEMU anyway.\r
    //\r
    Status = FdtClient->SetNodeProperty (FdtClient, Node, "status",\r
                          "disabled", sizeof ("disabled"));\r
    if (EFI_ERROR (Status)) {\r
      DEBUG ((DEBUG_WARN, "Failed to set NOR flash status to 'disabled'\n"));\r
    }\r
  }\r
\r
  *NorFlashDescriptions = mNorFlashDevices;\r
  *Count = Num;\r
\r
  return EFI_SUCCESS;\r
}\r