Re: [PATCH 2/2] ArmVirtPkg/NorFlashQemuLib: discover NOR flash banks dynamically

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

On Fri, 16 Nov 2018 at 16:45, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
>
> NorFlashQemuLib is one of the last remaining drivers in ArmVirtPkg
> that are not based on the device tree received from QEMU.
>
> For ArmVirtQemu, this does not really matter, given that the NOR
> flash banks are always the same: the PEI code is linked to execute
> in place from flash bank #0, and the fixed varstore PCDs refer to
> flash bank #1 directly.
>
> However, ArmVirtQemuKernel can execute at any offset, and flash bank

#0 is configured as secure-only when running with support for EL3 enabled.

> In this case, NorFlashQemuLib should not expose the first flash bank
> at all.
>
> To prevent introducing too much internal knowledge about which flash
> bank is accessible under which circumstances, let's switch to using
> the DTB to decide which flash banks to expose to the NOR flash driver.
>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.c   | 84 +++++++++++++++-----
>  ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.inf | 12 +++
>  2 files changed, 75 insertions(+), 21 deletions(-)
>
> diff --git a/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.c b/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.c
> index e3bbae5b06c5..dc0a15e77170 100644
> --- a/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.c
> +++ b/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.c
> @@ -1,6 +1,6 @@
>  /** @file
>
> - Copyright (c) 2014, Linaro Ltd. All rights reserved.<BR>
> + Copyright (c) 2014-2018, Linaro Ltd. All rights reserved.<BR>
>
>   This program and the accompanying materials
>   are licensed and made available under the terms and conditions of the BSD License
> @@ -12,13 +12,16 @@
>
>   **/
>
> +#include <Library/BaseLib.h>
> +#include <Library/DebugLib.h>
>  #include <Library/NorFlashPlatformLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +
> +#include <Protocol/FdtClient.h>
>
>  #define QEMU_NOR_BLOCK_SIZE    SIZE_256KB
> -#define QEMU_NOR0_BASE         0x0
> -#define QEMU_NOR0_SIZE         SIZE_64MB
> -#define QEMU_NOR1_BASE         0x04000000
> -#define QEMU_NOR1_SIZE         SIZE_64MB
> +
> +#define MAX_FLASH_BANKS        4
>
>  EFI_STATUS
>  NorFlashPlatformInitialization (
> @@ -28,21 +31,7 @@ NorFlashPlatformInitialization (
>    return EFI_SUCCESS;
>  }
>
> -NOR_FLASH_DESCRIPTION mNorFlashDevices[] = {
> -  {
> -    QEMU_NOR0_BASE,
> -    QEMU_NOR0_BASE,
> -    QEMU_NOR0_SIZE,
> -    QEMU_NOR_BLOCK_SIZE,
> -    {0xF9B94AE2, 0x8BA6, 0x409B, {0x9D, 0x56, 0xB9, 0xB4, 0x17, 0xF5, 0x3C, 0xB3}}
> -  }, {
> -    QEMU_NOR1_BASE,
> -    QEMU_NOR1_BASE,
> -    QEMU_NOR1_SIZE,
> -    QEMU_NOR_BLOCK_SIZE,
> -    {0x8047DB4B, 0x7E9C, 0x4C0C, {0x8E, 0xBC, 0xDF, 0xBB, 0xAA, 0xCA, 0xCE, 0x8F}}
> -  }
> -};
> +NOR_FLASH_DESCRIPTION mNorFlashDevices[MAX_FLASH_BANKS];
>
>  EFI_STATUS
>  NorFlashPlatformGetDevices (
> @@ -50,7 +39,60 @@ NorFlashPlatformGetDevices (
>    OUT UINT32                  *Count
>    )
>  {
> +  FDT_CLIENT_PROTOCOL         *FdtClient;
> +  INT32                       Node;
> +  EFI_STATUS                  Status;
> +  EFI_STATUS                  FindNodeStatus;
> +  CONST UINT64                *Reg;
> +  UINT32                      RegSize;
> +  CONST CHAR8                 *NodeStatus;
> +  UINTN                       Num;
> +
> +  Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,
> +                  (VOID **)&FdtClient);
> +  ASSERT_EFI_ERROR (Status);
> +
> +  Num = 0;
> +  for (FindNodeStatus = FdtClient->FindCompatibleNode (FdtClient,
> +                                     "cfi-flash", &Node);
> +       !EFI_ERROR (FindNodeStatus);
> +       FindNodeStatus = FdtClient->FindNextCompatibleNode (FdtClient,
> +                                     "cfi-flash", Node, &Node)) {
> +
> +    Status = FdtClient->GetNodeProperty (FdtClient, Node, "status",
> +                          (CONST VOID **)&NodeStatus, NULL);
> +    if (!EFI_ERROR (Status) && AsciiStrnCmp (NodeStatus, "ok", 2) != 0) {
> +      continue;
> +    }
> +
> +    Status = FdtClient->GetNodeProperty (FdtClient, Node, "reg",
> +                          (CONST VOID **)&Reg, &RegSize);
> +    if (EFI_ERROR (Status)) {
> +      DEBUG ((EFI_D_ERROR, "%a: GetNodeProperty () failed (Status == %r)\n",
> +        __FUNCTION__, Status));
> +      continue;
> +    }
> +
> +    ASSERT ((RegSize % (2 * sizeof(UINT64))) == 0);
> +
> +    while (RegSize > 0) {
> +      mNorFlashDevices[Num].DeviceBaseAddress = (UINTN)SwapBytes64 (Reg[0]);
> +      mNorFlashDevices[Num].RegionBaseAddress = (UINTN)SwapBytes64 (Reg[0]);
> +      mNorFlashDevices[Num].Size              = (UINTN)SwapBytes64 (Reg[1]);
> +      mNorFlashDevices[Num].BlockSize         = QEMU_NOR_BLOCK_SIZE;
> +
> +      Num++;
> +      Reg += 2;
> +      RegSize -= 2 * sizeof(UINT64);
> +
> +      if (Num >= MAX_FLASH_BANKS) {
> +        goto Finished;
> +      }
> +    }
> +  }
> +
> +Finished:
>    *NorFlashDescriptions = mNorFlashDevices;
> -  *Count = ARRAY_SIZE (mNorFlashDevices);
> +  *Count = Num;
>    return EFI_SUCCESS;
>  }
> diff --git a/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.inf b/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.inf
> index 126d1671f544..d86ff36dbd58 100644
> --- a/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.inf
> +++ b/ArmVirtPkg/Library/NorFlashQemuLib/NorFlashQemuLib.inf
> @@ -28,3 +28,15 @@
>  [Packages]
>    MdePkg/MdePkg.dec
>    ArmPlatformPkg/ArmPlatformPkg.dec
> +  ArmVirtPkg/ArmVirtPkg.dec
> +
> +[LibraryClasses]
> +  BaseLib
> +  DebugLib
> +  UefiBootServicesTableLib
> +
> +[Protocols]
> +  gFdtClientProtocolGuid          ## CONSUMES
> +
> +[Depex]
> +  gFdtClientProtocolGuid
> --
> 2.17.1
>