UEFI Tips 用按键做Pause

很多年前,我去AMI学习,偶然间看到他们在代码中加入通过 60/61 Port来读取键盘按键信息实现一个按需Delay ,深以为意。今天偶然间想起来,在调试Application 的时候,配合屏幕输出也可以用这样的方式来进行Debug。

下面是一个例子:

#include  <Uefi.h>
#include  <Library/UefiLib.h>
#include  <Library/ShellCEntryLib.h>


extern EFI_BOOT_SERVICES         *gBS;
extern EFI_SYSTEM_TABLE		 *gST;
extern EFI_RUNTIME_SERVICES 	 *gRT;

#define SCAN_NULL       0x0000
#define SCAN_UP         0x0001
#define SCAN_DOWN       0x0002
#define SCAN_ESC        0x0017

int
EFIAPI
main (
  IN int Argc,
  IN CHAR16 **Argv
  )
{
  EFI_INPUT_KEY	Key;
  EFI_STATUS		Status;  
  gST->ConOut->OutputString(gST->ConOut,L"Test Starting.....\n\r");
  gST->ConOut->OutputString(gST->ConOut,L"Waiting for UP_KEY\n\r");
  
  Key.ScanCode=SCAN_NULL;
  while (SCAN_UP!=Key.ScanCode)
    {
		Status= gST -> ConIn -> ReadKeyStroke(gST->ConIn,&Key);	
	}
  
  gST->ConOut->OutputString(gST->ConOut,L"Waiting for DOWN_KEY\n\r");	
  Key.ScanCode=SCAN_NULL;
  while (SCAN_DOWN!=Key.ScanCode)
    {
		Status= gST -> ConIn -> ReadKeyStroke(gST->ConIn,&Key);	
	}
  return EFI_SUCCESS;
}

 

通过按光标向上和向下继续运行,运行结果:

keypasue

完整文件下载

KeyPause

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