Step to UEFI (83) BlockIo Protocol

“因为硬盘是一种块设备,所以每个硬盘设备(硬盘设备包括分区设备)控制器都安装有一个 BlockIo 实例,一个 BlockIo2实例。BlockIo 提供了访问设备的阻塞函数,BlockIo2提供了访问设备的异步函数”【参考1】

blk2

blk1

这里提供一个枚举BlockIo,然后显示每一个 Media 属性的例子:

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

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

int
EFIAPI
main (
  IN int Argc,
  IN CHAR16 **Argv
  )
{
    EFI_STATUS				Status;
    UINTN					HandleCount,HandleIndex;
    EFI_HANDLE              *BlockControllerHandles = NULL;	
	EFI_BLOCK_IO_PROTOCOL   *BlockIo;
	
	//找到全部有 BlockIo Protocol 的Device
    Status = gBS->LocateHandleBuffer(
            ByProtocol,
            &gEfiBlockIoProtocolGuid,
            NULL,
            &HandleCount,
            &BlockControllerHandles);  

   if (!EFI_ERROR(Status)) {
        //逐个打开 
        for (HandleIndex = 0; HandleIndex < HandleCount; HandleIndex++) {
            /*打开EFI_BLOCK_IO_PROTOCOL  */ 
            Status = gBS->HandleProtocol(
                    BlockControllerHandles[HandleIndex],
                    &gEfiBlockIoProtocolGuid,
                    (VOID**)&BlockIo);
			//显示信息		
			Print(L"-->[Device]<--:%d\n",HandleIndex);
			Print(L"MediaId       :%0x\n",BlockIo->Media->MediaId);
    		Print(L"RemovableMedia:%0x\n",BlockIo->Media->RemovableMedia);
    		Print(L"MediaPresent  :%0x\n",BlockIo->Media->MediaPresent);
    		Print(L"ReadOnly      :%0x\n",BlockIo->Media->ReadOnly); 
    		Print(L"WriteCaching  :%0x\n",BlockIo->Media->WriteCaching);
    		Print(L"BlockSize     :%0x\n",BlockIo->Media->BlockSize);
    		Print(L"IoAlign       :%0x\n",BlockIo->Media->IoAlign);
    		Print(L"LastBlock     :%0x\n",BlockIo->Media->LastBlock);
    		Print(L"LogicalPartition :%0x\n",BlockIo->Media->LogicalPartition);
    		Print(L"LowestAlignedLba :%0x\n",BlockIo->Media->LowestAlignedLba);
    		Print(L"LogicalBlocksPerPhysicalBlock   : %0x\n",
			BlockIo->Media->LogicalBlocksPerPhysicalBlock);
    		Print(L"OptimalTransferLengthGranularity: %0x\n",
			BlockIo->Media->OptimalTransferLengthGranularity);
        }	//for (HandleIndex = 0;
		
        gBS->FreePool(BlockControllerHandles);
    }			
  return EFI_SUCCESS;
}

 

在 Nt32 虚拟机中运行的结果

blockioa

完整的代码和程序下载:

BIOTest

参考
1. UEFI 原理与编程 P139

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