嗨我是k66，前五篇我們實作Logo。今天來實作顯示即時系統時間，先上畫面。[自我挑戰7]為保證大家都能照著實作出，本篇有附上所有程式碼。讀者看到太長請不要害怕，重點僅有time.c的2個函式IoWrite8、IoRead8()，與CMOS_ADDRESS、CMOS_DATA。

放碼上來！程式碼連結

• 架構

|-edk2space\edk2\ #若非跟著系列文看上來的新手，edk2安裝請查看Day7
    |-OinkBLPkg
        |-time.c #重點，看IoWrite8、CMOS_ADDRESS、CMOS_DATA即可。
        |-time.h
        |-OinkBL.inf
        |-OinkBLPkg.dsc

• time.c
  查看系統時間我們使用IoWrite8()與IoRead8()這2個函式，裡面放CMOS地址與CMOS的地址指向的內容。舉例如要看此刻是星期幾，就用IoWrite8()將CMOS_ADDRESS寫入0x06，再讓CMOS_DATA透過IoRead8()去讀取。

#include<Time.h>
#define CMOS_ADDRESS 0x70
#define CMOS_DATA 0x71

EFI_STATUS
EFIAPI
UefiMain(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
{
    EFI_STATUS Status = EFI_SUCCESS;
    UINT8 sec=0;
    UINT8 min=0;
    UINT8 hour=0;
    UINT8 weekday=0;
    UINT8 day=0;
    UINT8 month=0;
    UINT8 year=0;
    
    // sec, 0x00
    IoWrite8(CMOS_ADDRESS,0x00);
    sec=IoRead8(CMOS_DATA);

    // min, 0x02
    IoWrite8(CMOS_ADDRESS,0x02);
    min=IoRead8(CMOS_DATA);

    // hour, 0x04
    IoWrite8(CMOS_ADDRESS,0x04);
    hour=IoRead8(CMOS_DATA);

    // weekday, 0x06
    IoWrite8(CMOS_ADDRESS,0x06);
    weekday=IoRead8(CMOS_DATA);

    // day, 0x07
    IoWrite8(CMOS_ADDRESS,0x07);
    day=IoRead8(CMOS_DATA);

    // month, 0x08
    IoWrite8(CMOS_ADDRESS,0x08);
    month=IoRead8(CMOS_DATA);

    // year, 0x09
    IoWrite8(CMOS_ADDRESS,0x09);
    year=IoRead8(CMOS_DATA);

    Print(L"Oink! Current time is: \n");
    Print(L"%02x/%02x/%02x  %02x  %02x:%02x:%02x\n",year,month,day,weekday,hour,min,sec);

    return Status;
}

• time.h

#include<Uefi.h>
#include<Library/UefiLib.h>
#include<Library/TimerLib.h>
#include<Library/UefiBootServicesTableLib.h>//gST
#include<Library/IoLib.h>

• OinkBL.inf

[Defines]
  INF_VERSION = 0x00010006
  BASE_NAME = OinkBL #output filename
  FILE_GUID = 7d371c5c-1a4d-41f9-9509-67632e5ce129
  MODULE_TYPE = UEFI_APPLICATION
  VERSION_STRING = 0.1
  ENTRY_POINT = UefiMain
  #UEFI_HII_RESOURCE_SECTION      = TRUE

[Sources]
  Time.c
  Time.h

[Packages]
  MdePkg/MdePkg.dec
  MdeModulePkg/MdeModulePkg.dec
  ShellPkg/ShellPkg.dec

[LibraryClasses]
  UefiApplicationEntryPoint#if .c use UefiMain(), then should use this.
  # ShellCEntryLib #If .c use ShellEntryMain(), then use it.
  UefiLib
  BmpSupportLib
  IoLib
  TimerLib
  
[Guids]
  gEfiFileInfoGuid

• OinkBLPkg.dsc

[Defines]
    PLATFORM_NAME = OinkBLPkg #output foldername
    PLATFORM_GUID = d6097f53-fca0-4540-a7b3-bb4008086628
    PLATFORM_VERSION = 0.1
    DSC_SPECIFICATION = 0x00010005
    SUPPORTED_ARCHITECTURES = X64
    BUILD_TARGETS = DEBUG|RELEASE

[LibraryClasses]
    UefiLib|MdePkg/Library/UefiLib/UefiLib.inf
    UefiApplicationEntryPoint|MdePkg/Library/UefiApplicationEntryPoint/UefiApplicationEntryPoint.inf
    PrintLib|MdePkg/Library/BasePrintLib/BasePrintLib.inf
    DebugLib|MdePkg/Library/BaseDebugLibNull/BaseDebugLibNull.inf
    BaseLib|MdePkg/Library/BaseLib/BaseLib.inf
    PcdLib|MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
    BaseMemoryLib|MdePkg/Library/BaseMemoryLib/BaseMemoryLib.inf
    MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
    UefiBootServicesTableLib|MdePkg/Library/UefiBootServicesTableLib/UefiBootServicesTableLib.inf
    DevicePathLib|MdePkg/Library/UefiDevicePathLib/UefiDevicePathLib.inf
    UefiRuntimeServicesTableLib|MdePkg/Library/UefiRuntimeServicesTableLib/UefiRuntimeServicesTableLib.inf
    BmpSupportLib|MdeModulePkg/Library/BaseBmpSupportLib/BaseBmpSupportLib.inf
    SafeIntLib|MdePkg/Library/BaseSafeIntLib/BaseSafeIntLib.inf
    RegisterFilterLib|MdePkg/Library/RegisterFilterLibNull/RegisterFilterLibNull.inf
    TimerLib|MdePkg/Library/BaseTimerLibNullTemplate/BaseTimerLibNullTemplate.inf
    IoLib|MdePkg/Library/BaseIoLibIntrinsic/BaseIoLibIntrinsic.inf
[Components]
    OinkBLPkg/OinkBL.inf #進入OinkBL.inf
    

總結

今天透過IoWrite8、IoRead8()、CMOS_ADDRESS、CMOS_DATA顯示系統時間。至今已完成Logo和及時系統時間顯示。未來幾天會實作bootloader(進到OS)與使用者互動介面，我們明天見！

自我挑戰7

今天寫的程式，如圖在shell內系統時間與Windows本機時間不同，想想看這是為什麼？如何解決？