system76-edk2/EmbeddedPkg/TemplateBds/BdsEntry.c

/** @file
  The entry of the embedded BDS. This BDS does not follow the Boot Manager requirements 
  of the UEFI specification as it is designed to implement an embedded systmes 
  propriatary boot scheme.

  This template assume a DXE driver produces a SerialIo protocol not using the EFI 
  driver module and it will attempt to connect a console on top of this.

  Copyright (c) 2008-2009, Apple Inc. All rights reserved.
  
  All rights reserved. This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include "BdsEntry.h"


BOOLEAN     gConsolePresent = FALSE;


EFI_HANDLE  mBdsImageHandle = NULL;
EFI_BDS_ARCH_PROTOCOL  gBdsProtocol = {
  BdsEntry,
};


 
 
/**
  This function uses policy data from the platform to determine what operating 
  system or system utility should be loaded and invoked.  This function call 
  also optionally make the use of user input to determine the operating system 
  or system utility to be loaded and invoked.  When the DXE Core has dispatched 
  all the drivers on the dispatch queue, this function is called.  This 
  function will attempt to connect the boot devices required to load and invoke 
  the selected operating system or system utility.  During this process, 
  additional firmware volumes may be discovered that may contain addition DXE 
  drivers that can be dispatched by the DXE Core.   If a boot device cannot be 
  fully connected, this function calls the DXE Service Dispatch() to allow the 
  DXE drivers from any newly discovered firmware volumes to be dispatched.  
  Then the boot device connection can be attempted again.  If the same boot 
  device connection operation fails twice in a row, then that boot device has 
  failed, and should be skipped.  This function should never return.

  @param  This             The EFI_BDS_ARCH_PROTOCOL instance.

  @return None.

**/
VOID
EFIAPI
BdsEntry (
  IN EFI_BDS_ARCH_PROTOCOL  *This
  )
{
  EFI_STATUS    Status;
  UINTN         NoHandles;
  EFI_HANDLE    *Buffer;
  UINTN         Index;
  EFI_HANDLE    FvHandle;
  EFI_GUID      *NameGuid;
  
  //
  // This code assumes that a DXE driver produces a SerialIo protocol not following the EFI
  // driver model. At a minimum we need to connect an EFI driver model terminal driver on top 
  // of the serial driver. 
  //
  Status = gBS->LocateHandleBuffer (ByProtocol, &gEfiSerialIoProtocolGuid, NULL, &NoHandles, &Buffer);
  if (!EFI_ERROR (Status)) {
    for (Index = 0; Index < NoHandles; Index++) {
      // For every Serial IO protocol in the system connect EFI drivers to it.
      // This should cause the terminal driver to bind to the Serial IO protocol and produce a 
      // child handle that produces SimpleTextOut & SImpleTextIn protocols
      gBS->ConnectController (Buffer[Index], NULL, NULL, TRUE);
    }
    
    FreePool (Buffer);
  }

  //
  // Now we need to setup the EFI System Table with information about the console devices.
  // This code is normally in the console spliter driver on platforms that support multiple 
  // consoles at the same time
  //
  Status = gBS->LocateHandleBuffer (ByProtocol, &gEfiSimpleTextOutProtocolGuid, NULL, &NoHandles, &Buffer);
  if (!EFI_ERROR (Status)) {
    // Use the first SimpleTextOut we find and update the EFI System Table
    gST->ConsoleOutHandle = Buffer[0];
    gST->StandardErrorHandle = Buffer[0];
    Status = gBS->HandleProtocol (Buffer[0], &gEfiSimpleTextOutProtocolGuid, (VOID **)&gST->ConOut);
    ASSERT_EFI_ERROR (Status);
    
    gST->StdErr = gST->ConOut;
          
    FreePool (Buffer);
    
    gConsolePresent = TRUE;
  }

  Status = gBS->LocateHandleBuffer (ByProtocol, &gEfiSimpleTextInProtocolGuid, NULL, &NoHandles, &Buffer);
  if (!EFI_ERROR (Status)) {
    // Use the first SimpleTextIn we find and update the EFI System Table
    gST->ConsoleInHandle = Buffer[0];
    Status = gBS->HandleProtocol (Buffer[0], &gEfiSimpleTextInProtocolGuid, (VOID **)&gST->ConIn);
    ASSERT_EFI_ERROR (Status);
    
    FreePool (Buffer);
  }

  //
  // We now have EFI Consoles up and running. Print () will work now. DEBUG () and ASSERT () worked 
  // prior to this point as they were configured to use a more primative output scheme.
  //

  
  //
  // Platform specific stuff goes here
  //


  //
  // Normal UEFI behavior is to process Globally Defined Variables as defined in Chapter 3 
  // (Boot Manager) of the UEFI specification. For this embedded system we don't do this.
  //

  //
  // Search all the FVs for an application with a UI Section of Ebl. A .FDF file can be used
  // to control the names of UI sections in an FV.
  //
  Status = FindApplicationMatchingUiSection (L"Ebl", &FvHandle, &NameGuid);
  if (EFI_ERROR (Status)) {
    //
    // Just load the first application we find reguardless of name.
    // This is the fallback path.
    //
    Status = FindApplicationMatchingUiSection (NULL, &FvHandle, &NameGuid);
    // Nothing to boot
    ASSERT_EFI_ERROR (Status);
  }

  Status = LoadPeCoffSectionFromFv (FvHandle, NameGuid);

  //
  // EFI does not define the bavior if all boot attemps fail and the last one returns. 
  // So we make a policy choice to reset the system since this BDS does not have a UI.
  //
  gRT->ResetSystem (EfiResetCold, Status, 0, NULL);

  return ;
}


EFI_STATUS
EFIAPI
BdsInitialize (
  IN EFI_HANDLE                            ImageHandle,
  IN EFI_SYSTEM_TABLE                      *SystemTable
  )
{
  EFI_STATUS  Status;

  mBdsImageHandle = ImageHandle;

  //
  // Install protocol interface
  //
  Status = gBS->InstallMultipleProtocolInterfaces (
                  &mBdsImageHandle,
                  &gEfiBdsArchProtocolGuid, &gBdsProtocol,
                  NULL
                  );
  ASSERT_EFI_ERROR (Status);

  return Status;
}