UEFI Framework - 6 [ EFI Console Services ]

在這個章節中會探討Console Services的觀念及使用


主要可以分為三大類

  1. Input
  2. Output
  3. Errors

Console 主要是使用下面兩個Protocols
  1. EFI Simple Text Input ：定義了最小的Input require給指定的ConIn Device
    2. typedef
EFI_STATUS
(EFIAPI *EFI_INPUT_READ_KEY)(
  IN EFI_SIMPLE_TEXT_INPUT_PROTOCOL       *This,
  OUT EFI_INPUT_KEY                       *Key
  );



typedef
EFI_STATUS
(EFIAPI *EFI_INPUT_RESET)(
  IN EFI_SIMPLE_TEXT_INPUT_PROTOCOL       *This,
  IN BOOLEAN                              ExtendedVerification
  );

///
/// The EFI_SIMPLE_TEXT_INPUT_PROTOCOL is used on the ConsoleIn device.
/// It is the minimum required protocol for ConsoleIn.
///
struct _EFI_SIMPLE_TEXT_INPUT_PROTOCOL {
  EFI_INPUT_RESET     Reset;
  EFI_INPUT_READ_KEY  ReadKeyStroke;
  ///
  /// Event to use with WaitForEvent() to wait for a key to be available
  ///
  EFI_EVENT           WaitForKey;
};
    1. Reset
    2. ReadKeyStroke
    3. WaitForKey     
      EFI_SIMPLE_TEXT_INPUT_PROTOCOL      SimpleInput;
  EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL     SimpleTextOutput;
  EFI_SIMPLE_TEXT_OUTPUT_MODE         SimpleTextOutputMode;


SimpleInput.Reset (&TerminalDevice->SimpleInput,
                   FALSE
                   );

if (TerminalDevice->SimpleInput.WaitForKey != NULL)
    在讀取key的時後有支援Scan code & Unicode


    1. Scan code
    2. Unicode
  2. EFI Simple Text Output ：定義了最小的Output require給指定的ConOut & StdOut Device
    3. struct _EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL {
  EFI_TEXT_RESET                Reset;

  EFI_TEXT_STRING               OutputString;
  EFI_TEXT_TEST_STRING          TestString;

  EFI_TEXT_QUERY_MODE           QueryMode;
  EFI_TEXT_SET_MODE             SetMode;
  EFI_TEXT_SET_ATTRIBUTE        SetAttribute;

  EFI_TEXT_CLEAR_SCREEN         ClearScreen;
  EFI_TEXT_SET_CURSOR_POSITION  SetCursorPosition;
  EFI_TEXT_ENABLE_CURSOR        EnableCursor;

  ///
  /// Pointer to SIMPLE_TEXT_OUTPUT_MODE data.
  ///
  EFI_SIMPLE_TEXT_OUTPUT_MODE   *Mode;
};

圖6.1中，介紹Input 跟 Output 之間互動的關係

而它們的定義是在SystemTable
路徑為 /MdePkg/Include/Uefi/UefiSpec.h
///
/// EFI System Table
///
typedef struct {
  ///
  /// The table header for the EFI System Table.
  ///
  EFI_TABLE_HEADER                  Hdr;
  ///
  /// A pointer to a null terminated string that identifies the vendor
  /// that produces the system firmware for the platform.
  ///
  CHAR16                            *FirmwareVendor;
  ///
  /// A firmware vendor specific value that identifies the revision
  /// of the system firmware for the platform.
  ///
  UINT32                            FirmwareRevision;
  ///
  /// The handle for the active console input device. This handle must support
  /// EFI_SIMPLE_TEXT_INPUT_PROTOCOL and EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL.
  ///
  EFI_HANDLE                        ConsoleInHandle;
  ///
  /// A pointer to the EFI_SIMPLE_TEXT_INPUT_PROTOCOL interface that is
  /// associated with ConsoleInHandle.
  ///
  EFI_SIMPLE_TEXT_INPUT_PROTOCOL    *ConIn;
  ///
  /// The handle for the active console output device.
  ///
  EFI_HANDLE                        ConsoleOutHandle;
  ///
  /// A pointer to the EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL interface
  /// that is associated with ConsoleOutHandle.
  ///
  EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL   *ConOut;
  ///
  /// The handle for the active standard error console device.
  /// This handle must support the EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL.
  ///
  EFI_HANDLE                        StandardErrorHandle;
  ///
  /// A pointer to the EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL interface
  /// that is associated with StandardErrorHandle.
  ///
  EFI_SIMPLE_TEXT_OUTPUT_PROTOCOL   *StdErr;
  ///
  /// A pointer to the EFI Runtime Services Table.
  ///
  EFI_RUNTIME_SERVICES              *RuntimeServices;
  ///
  /// A pointer to the EFI Boot Services Table.
  ///
  EFI_BOOT_SERVICES                 *BootServices;
  ///
  /// The number of system configuration tables in the buffer ConfigurationTable.
  ///
  UINTN                             NumberOfTableEntries;
  ///
  /// A pointer to the system configuration tables.
  /// The number of entries in the table is NumberOfTableEntries.
  ///
  EFI_CONFIGURATION_TABLE           *ConfigurationTable;
} EFI_SYSTEM_TABLE;



在裡面有六個主要的entries
  1. ConsoleInHandle – The handle for the active console input device.This handle must support the EFI Simple TextInput protocol
  2. ConIn                     – A pointer to the EFI Simple Text Input protocol                                  interface  that is associated with ConsoleInHandle.
  3. ConsoleOutHandle – The handle for the active console output device. This handle must support the EFI Simple Text output protocol
  4. ConOut – A pointer to the EFI Simple Text Output protocol interface that is associated with ConsoleOutHandle.
  5. StandardErrorHandle – The handle for the active standard error   console device. This handle must support the EFI Simple Text output protocol
  6. StdErr – A pointer to the EFI Simple Text Output  protocol interface that is associated with StandardErrorHandle.
     

而在下面圖中，有六個相關的Global Variable
在下面的表格中有解釋相關的意思
(#另外的Attribute的解釋可以看這篇文章 http://william30101.blogspot.com/2012/05/uefi-framework-5-efi-runtime.html )

  1. ConIn
  2. ConOut
  3. ErrOut
  4. ConInDev
  5. ConOutDev
  6. ErrOutDev



用法像code所示

gST->ConOut->SetAttribute(gST->ConOut, EFI_WHITE|EFI_BACKGROUND_GREEN);
if(gST->ConIn->ReadKeyStroke(gST->ConIn, &inputSelection) != EFI_NOT_READY )

留言

張貼留言