Drivers/ConsolePrefDxe/ConsolePrefDxe.c

/** @file
*
*  Copyright (c) 2017, Linaro, Ltd. All rights reserved.
*
*  SPDX-License-Identifier: BSD-2-Clause-Patent
*
**/

#include <Uefi.h>
#include <IndustryStandard/Acpi.h>
#include <libfdt.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/DevicePathLib.h>
#include <Library/HiiLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiDriverEntryPoint.h>
#include <Library/UefiLib.h>
#include <Library/UefiRuntimeServicesTableLib.h>

#include <Protocol/AcpiTable.h>
#include <Protocol/AcpiSystemDescriptionTable.h>

#include "ConsolePrefDxe.h"

#define SPCR_SIG    EFI_ACPI_2_0_SERIAL_PORT_CONSOLE_REDIRECTION_TABLE_SIGNATURE

extern  UINT8                     ConsolePrefHiiBin[];
extern  UINT8                     ConsolePrefDxeStrings[];

typedef struct {
  VENDOR_DEVICE_PATH              VendorDevicePath;
  EFI_DEVICE_PATH_PROTOCOL        End;
} HII_VENDOR_DEVICE_PATH;

STATIC HII_VENDOR_DEVICE_PATH     mConsolePrefDxeVendorDevicePath = {
  {
    {
      HARDWARE_DEVICE_PATH,
      HW_VENDOR_DP,
      {
        (UINT8) (sizeof (VENDOR_DEVICE_PATH)),
        (UINT8) ((sizeof (VENDOR_DEVICE_PATH)) >> 8)
      }
    },
    CONSOLE_PREF_FORMSET_GUID
  },
  {
    END_DEVICE_PATH_TYPE,
    END_ENTIRE_DEVICE_PATH_SUBTYPE,
    {
      (UINT8) (END_DEVICE_PATH_LENGTH),
      (UINT8) ((END_DEVICE_PATH_LENGTH) >> 8)
    }
  }
};

STATIC EFI_EVENT                  mReadyToBootEvent;

STATIC
EFI_STATUS
InstallHiiPages (
  VOID
  )
{
  EFI_STATUS                      Status;
  EFI_HII_HANDLE                  HiiHandle;
  EFI_HANDLE                      DriverHandle;

  DriverHandle = NULL;
  Status = gBS->InstallMultipleProtocolInterfaces (&DriverHandle,
                  &gEfiDevicePathProtocolGuid,
                  &mConsolePrefDxeVendorDevicePath,
                  NULL);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  HiiHandle = HiiAddPackages (&gConsolePrefFormSetGuid,
                              DriverHandle,
                              ConsolePrefDxeStrings,
                              ConsolePrefHiiBin,
                              NULL);

  if (HiiHandle == NULL) {
    gBS->UninstallMultipleProtocolInterfaces (DriverHandle,
           &gEfiDevicePathProtocolGuid,
           &mConsolePrefDxeVendorDevicePath,
           NULL);
    return EFI_OUT_OF_RESOURCES;
  }
  return EFI_SUCCESS;
}

STATIC
VOID
RemoveDtStdoutPath (
  VOID
)
{
  VOID        *Dtb;
  INT32       Node;
  INT32       Error;
  EFI_STATUS  Status;

  Status = EfiGetSystemConfigurationTable (&gFdtTableGuid, &Dtb);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_INFO, "%a: could not retrieve DT blob - %r\n", __FUNCTION__,
      Status));
    return;
  }

  Node = fdt_path_offset (Dtb, "/chosen");
  if (Node < 0) {
    return;
  }

  Error = fdt_delprop (Dtb, Node, "stdout-path");
  if (Error) {
    DEBUG ((DEBUG_INFO, "%a: Failed to delete 'stdout-path' property: %a\n",
      __FUNCTION__, fdt_strerror (Error)));
  }
}

STATIC
VOID
RemoveSpcrTable (
  VOID
  )
{
  EFI_ACPI_SDT_PROTOCOL           *Sdt;
  EFI_ACPI_TABLE_PROTOCOL         *AcpiTable;
  EFI_STATUS                      Status;
  UINTN                           TableIndex;
  EFI_ACPI_SDT_HEADER             *TableHeader;
  EFI_ACPI_TABLE_VERSION          TableVersion;
  UINTN                           TableKey;

  Status = gBS->LocateProtocol (&gEfiAcpiTableProtocolGuid, NULL,
                  (VOID **)&AcpiTable);
  if (EFI_ERROR (Status)) {
    return;
  }

  Status = gBS->LocateProtocol (&gEfiAcpiSdtProtocolGuid, NULL, (VOID **)&Sdt);
  if (EFI_ERROR (Status)) {
    return;
  }

  TableIndex  = 0;
  TableKey    = 0;
  TableHeader = NULL;

  do {
    Status = Sdt->GetAcpiTable (TableIndex++, &TableHeader, &TableVersion,
                    &TableKey);
    if (EFI_ERROR (Status)) {
      break;
    }

    if (TableHeader->Signature != SPCR_SIG) {
      continue;
    }

    Status = AcpiTable->UninstallAcpiTable (AcpiTable, TableKey);
    if (EFI_ERROR (Status)) {
      DEBUG ((DEBUG_WARN, "%a: failed to uninstall SPCR table - %r\n",
        __FUNCTION__, Status));
    }
    break;
  } while (TRUE);
}

STATIC
VOID
EFIAPI
OnReadyToBoot (
  IN EFI_EVENT  Event,
  IN VOID       *Context
  )
{
  CONSOLE_PREF_VARSTORE_DATA      ConsolePref;
  UINTN                           BufferSize;
  EFI_STATUS                      Status;
  VOID                            *Gop;

  BufferSize = sizeof (ConsolePref);
  Status = gRT->GetVariable (CONSOLE_PREF_VARIABLE_NAME,
                  &gConsolePrefFormSetGuid, NULL, &BufferSize, &ConsolePref);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR,
      "%a: variable '%s' could not be read - bailing!\n", __FUNCTION__,
      CONSOLE_PREF_VARIABLE_NAME));
    return;
  }

  if (ConsolePref.Console == CONSOLE_PREF_SERIAL) {
    DEBUG ((DEBUG_INFO,
      "%a: serial console preferred - doing nothing\n", __FUNCTION__));
    return;
  }

  //
  // Check if any GOP instances exist: if so, disable stdout-path and SPCR
  //
  Status = gBS->LocateProtocol (&gEfiGraphicsOutputProtocolGuid, NULL, &Gop);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_INFO,
      "%a: no GOP instances found - doing nothing (%r)\n", __FUNCTION__,
      Status));
    return;
  }

  RemoveDtStdoutPath ();
  RemoveSpcrTable ();
}

/**
  The entry point for ConsolePrefDxe driver.

  @param[in] ImageHandle     The image handle of the driver.
  @param[in] SystemTable     The system table.

  @retval EFI_ALREADY_STARTED     The driver already exists in system.
  @retval EFI_OUT_OF_RESOURCES    Fail to execute entry point due to lack of
                                  resources.
  @retval EFI_SUCCESS             All the related protocols are installed on
                                  the driver.

**/
EFI_STATUS
EFIAPI
ConsolePrefDxeEntryPoint (
  IN EFI_HANDLE                   ImageHandle,
  IN EFI_SYSTEM_TABLE             *SystemTable
  )
{
  EFI_STATUS                      Status;
  CONSOLE_PREF_VARSTORE_DATA      ConsolePref;
  UINTN                           BufferSize;

  //
  // Get the current console preference from the ConsolePref variable.
  //
  BufferSize = sizeof (ConsolePref);
  Status = gRT->GetVariable (CONSOLE_PREF_VARIABLE_NAME,
                  &gConsolePrefFormSetGuid, NULL, &BufferSize, &ConsolePref);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_INFO,
      "%a: no console preference found, defaulting to graphical\n",
      __FUNCTION__));
    ConsolePref.Console = CONSOLE_PREF_GRAPHICAL;
  }

  if (!EFI_ERROR (Status) &&
      ConsolePref.Console != CONSOLE_PREF_GRAPHICAL &&
      ConsolePref.Console != CONSOLE_PREF_SERIAL) {
    DEBUG ((DEBUG_WARN, "%a: invalid value for %s, defaulting to graphical\n",
      __FUNCTION__, CONSOLE_PREF_VARIABLE_NAME));
    ConsolePref.Console = CONSOLE_PREF_GRAPHICAL;
    Status = EFI_INVALID_PARAMETER; // trigger setvar below
  }

  //
  // Write the newly selected value back to the variable store.
  //
  if (EFI_ERROR (Status)) {
    ZeroMem (&ConsolePref.Reserved, sizeof (ConsolePref.Reserved));
    Status = gRT->SetVariable (CONSOLE_PREF_VARIABLE_NAME,
                    &gConsolePrefFormSetGuid,
                    EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS,
                    sizeof (ConsolePref), &ConsolePref);

    if (EFI_ERROR (Status)) {
      DEBUG ((DEBUG_ERROR, "%a: gRT->SetVariable () failed - %r\n",
        __FUNCTION__, Status));
      return Status;
    }
  }

  Status = gBS->CreateEventEx (EVT_NOTIFY_SIGNAL, TPL_CALLBACK,
                  OnReadyToBoot, NULL, &gEfiEventReadyToBootGuid,
                  &mReadyToBootEvent);
  ASSERT_EFI_ERROR (Status);

  return InstallHiiPages ();
}