Step to UEFI (105）DiskinfoProtocol

这次介绍一下用来取得系统上硬盘信息的 Protocol: EFI_DISK_INFO_PROTOCOL。

在\MdePkg\Include\Protocol\DiskInfo.h 有他的原型：

///
/// Forward declaration for EFI_DISK_INFO_PROTOCOL
///
typedef struct _EFI_DISK_INFO_PROTOCOL  EFI_DISK_INFO_PROTOCOL;
///
/// The EFI_DISK_INFO_PROTOCOL provides controller specific information.
///
struct _EFI_DISK_INFO_PROTOCOL {
  ///
  /// A GUID that defines the format of buffers for the other member functions 
  /// of this protocol.
  ///
  EFI_GUID                  Interface;
  ///
  /// Return the results of the Inquiry command to a drive in InquiryData. Data
  /// format of Inquiry data is defined by the Interface GUID.
  ///
  EFI_DISK_INFO_INQUIRY     Inquiry;
  ///
  /// Return the results of the Identify command to a drive in IdentifyData. Data
  /// format of Identify data is defined by the Interface GUID.
  ///
  EFI_DISK_INFO_IDENTIFY    Identify;
  ///
  /// Return the results of the Request Sense command to a drive in SenseData. Data
  /// format of Sense data is defined by the Interface GUID.
  ///
  EFI_DISK_INFO_SENSE_DATA  SenseData;
  ///
  /// Specific controller. 
  ///
  EFI_DISK_INFO_WHICH_IDE   WhichIde;
};

更详细的介绍可以在 PI Specification 1.4 上找到。
对于不同类型的设备，比如 IDE 和 USB ，返回的数据格式是不同的。枚举到这个 PROTOCOL 之后需要检查EFI_GUID Interface 通过不同的GUID得知当前设备的类型。
下面先编写一个简单的 Demo，检查 GUID ，判断当前设备的类型：

#include  <Uefi.h>
#include  <Library/UefiLib.h>
#include  <Library/ShellCEntryLib.h>
#include  <Library/ShellCEntryLib.h>
#include  <Protocol/DiskInfo.h>
#include  <Library/BaseMemoryLib.h>

extern EFI_BOOT_SERVICES         *gBS;

extern EFI_HANDLE				 gImageHandle;

EFI_GUID gEfiDiskInfoProtocolGuid = { 0xD432A67F, 0x14DC, 0x484B, 
					{ 0xB3, 0xBB, 0x3F, 0x02, 0x91, 0x84, 0x93, 0x27 }};

EFI_GUID gEfiDiskInfoIdeInterfaceGuid   = { 0x5E948FE3, 0x26D3, 0x42B5, 
					{ 0xAF, 0x17, 0x61, 0x02, 0x87, 0x18, 0x8D, 0xEC }};
EFI_GUID gEfiDiskInfoScsiInterfaceGuid  = { 0x08F74BAA, 0xEA36, 0x41D9, 
					{ 0x95, 0x21, 0x21, 0xA7, 0x0F, 0x87, 0x80, 0xBC }};
EFI_GUID gEfiDiskInfoUsbInterfaceGuid   = { 0xCB871572, 0xC11A, 0x47B5, 
					{ 0xB4, 0x92, 0x67, 0x5E, 0xAF, 0xA7, 0x77, 0x27 }};
EFI_GUID gEfiDiskInfoAhciInterfaceGuid  = { 0x9e498932, 0x4abc, 0x45af, 
					{ 0xa3, 0x4d, 0x02, 0x47, 0x78, 0x7b, 0xe7, 0xc6 }};
EFI_GUID gEfiDiskInfoNvmeInterfaceGuid  = { 0x3ab14680, 0x5d3f, 0x4a4d, 
					{ 0xbc, 0xdc, 0xcc, 0x38, 0x0, 0x18, 0xc7, 0xf7 }};
EFI_GUID gEfiDiskInfoUfsInterfaceGuid   = { 0x4b3029cc, 0x6b98, 0x47fb, 
					{ 0xbc, 0x96, 0x76, 0xdc, 0xb8, 0x4, 0x41, 0xf0 }};
int
EFIAPI
main (
  IN int Argc,
  IN CHAR16 **Argv
  )
{
    EFI_STATUS Status;
    UINTN HandleIndex, NumHandles;
    EFI_HANDLE *ControllerHandle = NULL;
	EFI_DISK_INFO_PROTOCOL	*DiskInfoProtocol;
	
    Status = gBS->LocateHandleBuffer(
            ByProtocol,
            &gEfiDiskInfoProtocolGuid,
            NULL,
            &NumHandles,
            &ControllerHandle);
	
    for (HandleIndex = 0; HandleIndex < NumHandles; HandleIndex++) {
        Status = gBS->OpenProtocol(
                ControllerHandle[HandleIndex],
                &gEfiDiskInfoProtocolGuid, 
                (VOID**)&DiskInfoProtocol,
                gImageHandle,
                NULL,
                EFI_OPEN_PROTOCOL_GET_PROTOCOL
                );		
        if (EFI_ERROR(Status)) {
            continue;
        } 
		
		Print(L"Device[%d] GUID: %g",
				HandleIndex,
				DiskInfoProtocol->Interface);
		if (CompareGuid (
				&DiskInfoProtocol->Interface, 
			&gEfiDiskInfoIdeInterfaceGuid)) {	
				Print(L" IDE HDD\n");
			}	
		if (CompareGuid (
				&DiskInfoProtocol->Interface, 
			&gEfiDiskInfoScsiInterfaceGuid)) {	
				Print(L" Scsi HDD\n");
			}	
		if (CompareGuid (
				&DiskInfoProtocol->Interface, 
			&gEfiDiskInfoUsbInterfaceGuid)) {	
				Print(L" USB HDD\n");
			}	
		if (CompareGuid (
				&DiskInfoProtocol->Interface, 
			&gEfiDiskInfoAhciInterfaceGuid)) {	
				Print(L" AHCI HDD\n");
			}	
		if (CompareGuid (
				&DiskInfoProtocol->Interface, 
			&gEfiDiskInfoNvmeInterfaceGuid)) {	
				Print(L" NVME HDD\n");
			}	
		if (CompareGuid (
				&DiskInfoProtocol->Interface, 
			&gEfiDiskInfoUfsInterfaceGuid)) {	
				Print(L" Ufs HDD\n");
			}				
	}

  return EFI_SUCCESS;
}

上述代码在UDK2014中编译通过，但是无法在 NT32环境下运行。于是在实体机KabyLake HDK 上实验, 板子上挂载了一个 SATA HDD 一个eMMC和两个USB Disk。运行结果如下：

可以看出，当前的SATA 是AHCI 模式。此外， eMMC 设备是无法被识别出来的，也许后面会扩展到这种设备吧。
完整的代码下载：

diskinfotest