MdeModulePkg/Application/HelloWorld/HelloWorld.c

   1 /** @file
   2   This sample application bases on HelloWorld PCD setting
   3   to print "UEFI Hello World!" to the UEFI Console.
   4
   5   Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
   6   This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #include <Uefi.h>
  17 #include <Library/PcdLib.h>
  18 #include <Library/UefiLib.h>
  19 #include <Library/UefiApplicationEntryPoint.h>
  20
  21 //
  22 // String token ID of help message text.
  23 // Shell supports to find help message in the resource section of an application image if
  24 // .MAN file is not found. This global variable is added to make build tool recognizes
  25 // that the help string is consumed by user and then build tool will add the string into
  26 // the resource section. Thus the application can use '-?' option to show help message in
  27 // Shell.
  28 //
  29 GLOBAL_REMOVE_IF_UNREFERENCED EFI_STRING_ID mStringHelpTokenId = STRING_TOKEN (STR_HELLO_WORLD_HELP_INFORMATION);
  30
  31 /**
  32   The user Entry Point for Application. The user code starts with this function
  33   as the real entry point for the application.
  34
  35   @param[in] ImageHandle    The firmware allocated handle for the EFI image.
  36   @param[in] SystemTable    A pointer to the EFI System Table.
  37
  38   @retval EFI_SUCCESS       The entry point is executed successfully.
  39   @retval other             Some error occurs when executing this entry point.
  40
  41 **/
  42 EFI_STATUS
  43 EFIAPI
  44 UefiMain (
  45   IN EFI_HANDLE        ImageHandle,
  46   IN EFI_SYSTEM_TABLE  *SystemTable
  47   )
  48 {
  49         UINT32 Index;
  50
  51         Index = 0;
  52
  53   //
  54   // Three PCD type (FeatureFlag, UINT32 and String) are used as the sample.
  55   //
  56   if (FeaturePcdGet (PcdHelloWorldPrintEnable)) {
  57         for (Index = 0; Index < PcdGet32 (PcdHelloWorldPrintTimes); Index ++) {
  58           //
  59           // Use UefiLib Print API to print string to UEFI console
  60           //
  61         Print ((CHAR16*)PcdGetPtr (PcdHelloWorldPrintString));
  62     }
  63   }
  64
  65   return EFI_SUCCESS;
  66 }