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 - 2018, Intel Corporation. All rights reserved.<BR>
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 #include <Uefi.h>
  11 #include <Library/PcdLib.h>
  12 #include <Library/UefiLib.h>
  13 #include <Library/UefiApplicationEntryPoint.h>
  14
  15 //
  16 // String token ID of help message text.
  17 // Shell supports to find help message in the resource section of an application image if
  18 // .MAN file is not found. This global variable is added to make build tool recognizes
  19 // that the help string is consumed by user and then build tool will add the string into
  20 // the resource section. Thus the application can use '-?' option to show help message in
  21 // Shell.
  22 //
  23 GLOBAL_REMOVE_IF_UNREFERENCED EFI_STRING_ID mStringHelpTokenId = STRING_TOKEN (STR_HELLO_WORLD_HELP_INFORMATION);
  24
  25 /**
  26   The user Entry Point for Application. The user code starts with this function
  27   as the real entry point for the application.
  28
  29   @param[in] ImageHandle    The firmware allocated handle for the EFI image.
  30   @param[in] SystemTable    A pointer to the EFI System Table.
  31
  32   @retval EFI_SUCCESS       The entry point is executed successfully.
  33   @retval other             Some error occurs when executing this entry point.
  34
  35 **/
  36 EFI_STATUS
  37 EFIAPI
  38 UefiMain (
  39   IN EFI_HANDLE        ImageHandle,
  40   IN EFI_SYSTEM_TABLE  *SystemTable
  41   )
  42 {
  43   UINT32 Index;
  44
  45   Index = 0;
  46
  47   //
  48   // Three PCD type (FeatureFlag, UINT32 and String) are used as the sample.
  49   //
  50   if (FeaturePcdGet (PcdHelloWorldPrintEnable)) {
  51     for (Index = 0; Index < PcdGet32 (PcdHelloWorldPrintTimes); Index ++) {
  52       //
  53       // Use UefiLib Print API to print string to UEFI console
  54       //
  55       Print ((CHAR16*)PcdGetPtr (PcdHelloWorldPrintString));
  56     }
  57   }
  58
  59   return EFI_SUCCESS;
  60 }