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Step to UEFI (41） —– x64 的 FreqCalc程序

之前的一篇文章《Step to UEFI (9)—-使用RDTSC计算当前CPU 频率》【参考1】给出了一个计算当前CPU频率的方法。不过 Tim 给我留言，他说这篇文章的程序无法在 x64下正常编译：

我猜测原因是因为我的程序使用的内嵌汇编，内嵌汇编无法被X64的编译器正常编译的。关于这个说法可以看【参考2】。

动手在 UDK2014 下面实验，不过在看到描述的问题之前还是要走一段路的。

使用编译命令 build -a X64 -p AppPkg\AppPkg.dsc 得到下面的错误信息

c:\edk\AppPkg\AppPkg.dsc(94): error 000E: File/directory not found in workspace
        c:\edk\PerformancePkg\Library\DxeTscTimerLib\DxeTscTimerLib.inf

检查 AppPkg.dsc

修改

[LibraryClasses.X64]
  TimerLib|PerformancePkg/Library/DxeTscTimerLib/DxeTscTimerLib.inf

修改为

[LibraryClasses.X64]
  TimerLib|PerformancePkg/Library/TscTimerLib/DxeTscTimerLib.inf

再次编译，有下面的错误信息

Processing meta-data .. done!
Building ... c:\edk\MdePkg\Library\BaseLib\BaseLib.inf [X64]
        "C:\Program Files\Microsoft Visual Studio 9.0\Vc\bin\x86_amd64\cl.exe" /Foc:\edk\Build\AppPkg\DEBUG_MYTOOLS\X64\MdePkg\Library\BaseLib\BaseLib\OUTPUT\.\CheckSum.obj /nologo /c /WX /GS- /W4 /Gs32768 /Gy /D UNICODE /O1ib2 /GL /FIAutoG
en.h /EHs-c- /GR- /GF /Zi /Gm /X /Zc:wchar_t /X /Zc:wchar_t /GL- /Ic:\edk\MdePkg\Library\BaseLib\X64  /Ic:\edk\MdePkg\Library\BaseLib  /Ic:\edk\Build\AppPkg\DEBUG_MYTOOLS\X64\MdePkg\Library\BaseLib\BaseLib\DEBUG  /Ic:\edk\MdePkg  /Ic:\edk\M
dePkg\Include  /Ic:\edk\MdePkg\Include\X64 c:\edk\MdePkg\Library\BaseLib\CheckSum.c
'C:\Program' 不是内部或外部命令，也不是可运行的程序或批处理文件。
NMAKE : fatal error U1077: '"C:\Program Files\Microsoft Visual Studio 9.0\Vc\bin\x86_amd64\cl.exe' : return code '0x1' Stop.


build...
 : error 7000: Failed to execute command
        C:\Program Files\Microsoft Visual Studio 9.0\Vc\bin\nmake.exe /nologo tbuild 

build...
 : error 7000: Failed to execute command
        C:\Program Files\Microsoft Visual Studio 9.0\Vc\bin\nmake.exe /nologo tbuild 


build...
 : error F002: Failed to build module
        c:\edk\MdePkg\Library\BaseLib\BaseLib.inf [X64, MYTOOLS, DEBUG]

- Failed -
Build end time: 11:22:09, Mar.09 2015
Build total time: 00:00:03

尝试在命令行窗口直接运行”C:\Program Files\Microsoft Visual Studio 9.0\Vc\bin\x86_amd64\cl.exe” 错误提示是：

C:\EDK>"C:\Program Files\Microsoft Visual Studio 9.0\Vc\bin\x86_amd64\cl.exe"
系统找不到指定的路径。

这是因为目前的编译环境缺少 64位编译器。我使用的是 vs2008 express 版本，默认是没有 64位的cl.exe的。

找到 ‘x86_amd64’ 拷贝到 “C:\Program Files\Microsoft Visual Studio 9.0\VC\bin”

需要的朋友可以在这里下载到 x86_amd64

再次编译，然后就能看到 Tim 说的问题啦

C:\Program Files\Microsoft Visual Studio 9.0\VC\bin

Building ... c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.inf [X64]
        "C:\Program Files\Microsoft Visual Studio 9.0\Vc\bin\x86_amd64\cl.exe" /Foc:\edk\Build\AppPkg\DEBUG_MYTOOLS\X64\AppPkg\Applications\FreqCalc\FreqCalc\OUTPUT\.\FreqCalc.obj /nologo /c /WX /GS- /W4 /Gs32768 /Gy /D UNICODE /O1ib2 /GL /
FIAutoGen.h /EHs-c- /GR- /GF /Zi /Gm /X /Zc:wchar_t /Ic:\edk\AppPkg\Applications\FreqCalc  /Ic:\edk\Build\AppPkg\DEBUG_MYTOOLS\X64\AppPkg\Applications\FreqCalc\FreqCalc\DEBUG  /Ic:\edk\MdePkg  /Ic:\edk\MdePkg\Include  /Ic:\edk\MdePkg\Includ
e\X64  /Ic:\edk\ShellPkg  /Ic:\edk\ShellPkg\Include  /Ic:\edk\MdeModulePkg  /Ic:\edk\MdeModulePkg\Include c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c
FreqCalc.c
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(15) : error C4235: nonstandard extension used : '__asm' keyword not supported on this architecture
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(18) : error C2146: syntax error : missing ';' before identifier 'mov'
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(18) : warning C4550: expression evaluates to a function which is missing an argument list
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(18) : error C2065: 'mov' : undeclared identifier
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(18) : error C2146: syntax error : missing ';' before identifier 'dword'
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(18) : error C2065: 'dword' : undeclared identifier
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(18) : error C2146: syntax error : missing ';' before identifier 'ptr'
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(18) : error C2065: 'ptr' : undeclared identifier
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(18) : error C2146: syntax error : missing ';' before identifier 'value'
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(19) : error C2065: 'eax' : undeclared identifier
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(19) : error C2146: syntax error : missing ';' before identifier 'mov'
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(19) : error C2065: 'mov' : undeclared identifier
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(19) : error C2146: syntax error : missing ';' before identifier 'dword'
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(19) : error C2065: 'dword' : undeclared identifier
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(19) : error C2146: syntax error : missing ';' before identifier 'ptr'
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(19) : error C2065: 'ptr' : undeclared identifier
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(19) : error C2109: subscript requires array or pointer type
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(20) : error C2065: 'edx' : undeclared identifier
c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.c(20) : error C2143: syntax error : missing ';' before '}'
NMAKE : fatal error U1077: '"C:\Program Files\Microsoft Visual Studio 9.0\Vc\bin\x86_amd64\cl.exe"' : return code '0x2'
Stop.


build...
 : error 7000: Failed to execute command
        C:\Program Files\Microsoft Visual Studio 9.0\Vc\bin\nmake.exe /nologo tbuild 


build...
 : error F002: Failed to build module
        c:\edk\AppPkg\Applications\FreqCalc\FreqCalc.inf [X64, MYTOOLS, DEBUG]

- Failed -
Build end time: 11:26:31, Mar.09 2015
Build total time: 00:01:16

然后就考虑如何解决，网上搜索了一下，有人遇到同样的问题【参考3】，具体的解决方法在【参考4】

简单的说，就是单独写一个 asm 然后在对应的 Inf中声明一下即可。

针对我遇到的问题，程序如下

FreqCalc.inf

## @file
#  Sample UEFI Application Reference EDKII Module
#
#  This is a sample shell application that will print "UEFI Hello World!" to the 
#  UEFI Console based on PCD setting.
#
#  It demos how to use EDKII PCD mechanism to make code more flexible.
#
#  Copyright (c) 2008 - 2011, Intel Corporation. All rights reserved.<BR>
#
#  This program and the accompanying materials
#  are licensed and made available under the terms and conditions of the BSD License
#  which accompanies this distribution. The full text of the license may be found at
#  http://opensource.org/licenses/bsd-license.php
#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
#
#
##

[Defines]
  INF_VERSION                    = 0x00010005
  BASE_NAME                      = FreqCalc
  FILE_GUID                      = 6987936E-ED34-44db-AE97-2FA5E4ED2216
  MODULE_TYPE                    = UEFI_APPLICATION
  VERSION_STRING                 = 1.0
  ENTRY_POINT                    = UefiMain 

#
# The following information is for reference only and not required by the build tools.
#
#  VALID_ARCHITECTURES           = IA32 X64 IPF EBC
#

[Sources]
  FreqCalc.c
  ReadTsc1.asm

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

[LibraryClasses]
  UefiApplicationEntryPoint
  UefiLib
  PcdLib
  ShellCEntryLib
  ShellLib


[FeaturePcd]


[Pcd]

然后在FreqCalc.c 写成下面这样，特别注意要声明一下你用的那个汇编语言中的函数名

//
// FreqCalc.C
//

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

EFI_SYSTEM_TABLE	*gST;
EFI_BOOT_SERVICES  	*gBS;

UINT64
EFIAPI
zReadTsc (
  VOID
);

//
// Entry point function - ShowVersion
//
EFI_STATUS
EFIAPI
UefiMain (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{

  UINT64  elsp;

  gST = SystemTable;
  gBS = SystemTable->BootServices;

  elsp=zReadTsc();

  gBS -> Stall(1000000);  
  Print(L"CPU Frequency: %ld \n",zReadTsc() - elsp);

  return EFI_SUCCESS;
}

然后还有一个ReadTsc1.asm （其实 uefi 里面提供了一个 x64的 ReadTsc.asm，可以直接使用，这里是为了让读者看的更清楚，取了一个不会重复的名称）

    .code

;------------------------------------------------------------------------------
; UINT64
; EFIAPI
; zReadTsc (
;   VOID
;   );
;------------------------------------------------------------------------------
zReadTsc  PROC
    rdtsc
    shl     rdx, 20h
    or      rax, rdx
    ret
zReadTsc  ENDP

    END

接下来就可以正常编译了，生成的 efi 文件会比 x64的大一些。然后我在实体机的 x64 shell下面运行成功。就是说上面的方法是没问题的。

FreqCalc

参考:

1.http://www.lab-z.com/rdtsc/ Step to UEFI (9)—-使用RDTSC计算当前CPU 频率

2.http://stackoverflow.com/questions/1295452/why-does-msvc-not-support-inline-assembly-for-amd64-and-itanium-targets 简单解释，说x64下无法支持 _ASM汇编

3.http://biosren.com/viewthread.php?tid=6822&highlight=%C4%DA%C7%B6%2B%BB%E3%B1%E0 請問如何在EDK2的AppPkg裡面使用asm （有人问同样的问题）

4.http://www.biosren.com/thread-6632-1-1.html 給個UEFI 內嵌彙編的小程序吧？本文的主要参考，其中介绍了如何写单独写一个ASM文件

Step to UEFI (40） —– 从Shell下向Windows传值

很早之前，BIOS如果想把一些值传递给OS，通常都是使用CMOS的。但是这样的方法有着下面的缺点：复杂度高，需要和使用位置的人协商，否则没人知道你放在CMOS中什么地方
不确定性大，可能会在代码中冲突，无法确定别人是否也用到你选择的那个CMOS位
每次传递值少，CMOS一般也就128 BYTES,很容易耗尽。

现在进化到了UEFI的时代，可以在 Shell 上将一些内容存放在内存中，然后轻松的传输到Windows中。这里只是演示这种做法，总体来说还是非常简单的。

最关键的函数就是下面这个：

Status = pBS->AllocatePool(EfiReservedMemoryType, Hdr1->Length, &Ptr);

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

#include  <stdio.h>
#include  <stdlib.h>
#include  <wchar.h>
#include <Protocol/EfiShell.h>
#include <Library/ShellLib.h>

#include <Protocol/SimpleFileSystem.h>
#include <Protocol/BlockIo.h>
#include <Library/DevicePathLib.h>
#include <Library/HandleParsingLib.h>
#include <Library/SortLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/BaseMemoryLib.h>

extern EFI_SYSTEM_TABLE			 *gST;
extern EFI_BOOT_SERVICES         *gBS;

int
EFIAPI
main (                                         
  IN int Argc,
  IN char **Argv
  )
{
  EFI_STATUS                Status;	
  UINT8                		*Buffer;  
  
  Status = gBS -> AllocatePool (EfiACPIMemoryNVS, 0x100 , & Buffer);

  * Buffer    = 'L';
  *(Buffer+1) = 'A';  
  *(Buffer+2) = 'B';  
  *(Buffer+3) = '-';  
  *(Buffer+4) = 'Z';  
  *(Buffer+5) = '.';  
  *(Buffer+6) = 'C';  
  *(Buffer+7) = 'O';  
  *(Buffer+8) = 'M';    
  *(Buffer+9) = '1';   
  printf("Memory1 [%x]\n",Buffer);
  
  //Status = gBS -> FreePool (Buffer);

    Status = gBS -> AllocatePool (EfiReservedMemoryType, 0x100 , & Buffer);

  * Buffer    = 'L';
  *(Buffer+1) = 'A';  
  *(Buffer+2) = 'B';  
  *(Buffer+3) = '-';  
  *(Buffer+4) = 'Z';  
  *(Buffer+5) = '.';  
  *(Buffer+6) = 'C';  
  *(Buffer+7) = 'O';  
  *(Buffer+8) = 'M';    
  *(Buffer+9) = '2';   
  printf("Memory2 [%x]\n",Buffer);
  
  return EFI_SUCCESS;
}

运行结果（虚拟机下面的测试）

直接查看，可以看到确实在内存中写入了

再检查一下E820 Table,可以看到放置字符串的内存已经被标记为占用

之后，我们在实体机器上运行，首先还是shell下面写，然后到Windows中读取对应的内存。可以看到我们在对应的内存中能够看到写入的String.

因此，这个方法是可行的。

代码下载
Mem2OS

Step to UEFI (37） —– SetTimer 设定定时器（上）

众所周知：UEFI中没有中断（UEFI唯一一个中断int 0,timer ）【参考1】，如果想实现一个定时器的功能，必须使用 Event。

实现的思路是：

1. CreateEvent 创建 Timer Event
2. SetTimer 设定 Periodic 触发
3. SetTimer 关闭定时器
4. CloseEvent 销毁 Timer Event

首先研究 CreateEvent ，这个函数是Boot Service中提供的【参考3】

第一个参数给出创建的类型，我们要选择EVT_TIMER；第二个参数是优先级，对我们来说影响不大；第三个参数给出当Event发生时对应的处理函数；第四个参数我的理解是自定义的数据；第五个参数是创建出来的Event。

接下来再看看SetTimer函数，同样也是 Boot Service 中提供的服务

第一个参数是你创建的Event；然后是Timer的类型，比如：周期性触发；最后是设定Timer的时间，多久触发一次，单位是100ns。

CloseEvent就很简单了

程序还参考了 ShellPkg\Library\UefiShellNetwork1CommandsLib\Ping.c 的代码。

最终代码如下

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

#include  <stdio.h>
#include  <stdlib.h>
#include  <wchar.h>

#include <Protocol/EfiShell.h>
#include <Library/ShellLib.h>

#include <Protocol/SimpleFileSystem.h>
#include <Protocol/BlockIo.h>
#include <Library/DevicePathLib.h>
#include <Library/HandleParsingLib.h>
#include <Library/SortLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/BaseMemoryLib.h>

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

extern EFI_SHELL_ENVIRONMENT2    *mEfiShellEnvironment2;
extern EFI_HANDLE				 gImageHandle;

STATIC CONST UINTN SecondsToNanoSeconds = 10000000;

UINTN	Counter = 0;
/**
  The callback function for the timer event used to get map.

  @param[in] Event    The event this function is registered to.
  @param[in] Context  The context registered to the event.
**/
VOID
EFIAPI
Timeout (
  IN EFI_EVENT      Event,
  IN VOID           *Context
  )
{
  Print(L"www.lab-z.com [%d]\r\n",++ Counter);
  return ;
}

int
EFIAPI
main (                                         
  IN int Argc,
  IN char **Argv
  )
{
  EFI_STATUS                Status;
  EFI_HANDLE                TimerOne = NULL;
  BOOLEAN					ExitMark=FALSE;
  
  Status  = gBS->CreateEvent (
                    EVT_NOTIFY_SIGNAL | EVT_TIMER,
                    TPL_CALLBACK,
                    Timeout,
                    NULL,
                    &TimerOne
                    );
    
    if (EFI_ERROR (Status)) {
        Print(L"Create Event Error! \r\n");
		return ;
    }

    Status = gBS->SetTimer (
                   TimerOne,
                   TimerPeriodic,
                   MultU64x32 (SecondsToNanoSeconds, 1)
                   );
    
    if (EFI_ERROR (Status)) {
        Print(L"Set Timer Error! \r\n");
		return ;
    }

	while (!ExitMark)
	{
		if (mEfiShellEnvironment2 -> GetExecutionBreak()) {ExitMark=TRUE;}
	}
    gBS->SetTimer (TimerOne, TimerCancel, 0);
    gBS->CloseEvent (TimerOne);	

  return EFI_SUCCESS;
}

运行结果如下

完整代码下载
TimerTest

后记：这部分对我来说还是比较复杂，在描述上定义概念可能会有偏差，如果阅读中发现，欢迎通知我及时改正。

参考：

1. http://blog.csdn.net/celiaqianhj/article/details/7180783 UEFI Events
2. http://biosren.com/viewthread.php?tid=2095&highlight=%B6%A8%CA%B1 什么是EFI Events?
3. UEFI Spec 2.4 P118

Step to UEFI (36) —– 枚举Shell下的全部盘符

目标：写一个小程序来枚举当前系统中的盘符。比如：FS0: FS1: 等等。

和这个需求最相近的参考文件是 map 功能，每次启动shell的时候他都会展示一下当前系统中的全部盘符。这个功能的代码在 ShellPkg\Library\UefiShellLevel2CommandsLib\Map.c 。大概研究了一下，实现的方法是分别枚举有 Simple File Protocol 和 Block IO Protocol 的Handle （在 PerformMappingDisplay 函数中），然后取每的 Device Path Protocol（在 PerformSingleMappingDisplay 函数中），最后从这个Protocol中获取对应的盘符。

map.c中使用 gEfiShellProtocol->GetMapFromDevicePath 功能取得名称，但是在实际测试过程中我的程序中取得到的 gEfiShellProtocol 不知为何一直为0. 最后只得使用 mEfiShellEnvironment2 -> GetFsName 来完实现这个功能。

ShellPkg\Include\Protocol\EfiShellEnvironment2.h 有 EFI_SHELL_ENVIRONMENT2的定义

/// EFI_SHELL_ENVIRONMENT2 protocol structure.
typedef struct {
  SHELLENV_EXECUTE                        Execute;
  SHELLENV_GET_ENV                        GetEnv;
  SHELLENV_GET_MAP                        GetMap;
  SHELLENV_ADD_CMD                        AddCmd;
  SHELLENV_ADD_PROT                       AddProt;
  SHELLENV_GET_PROT                       GetProt;
                          CurDir;
  SHELLENV_FILE_META_ARG                  FileMetaArg;
  SHELLENV_FREE_FILE_LIST                 FreeFileList;

  //
  // The following services are only used by the shell itself.
  //
  SHELLENV_NEW_SHELL                      NewShell;
  SHELLENV_BATCH_IS_ACTIVE                BatchIsActive;

  SHELLENV_FREE_RESOURCES                 FreeResources;

  //
  // GUID to differentiate ShellEnvironment2 from ShellEnvironment.
  //
  EFI_GUID                                SESGuid;
  //
  // Major Version grows if shell environment interface has been changes.
  //
  UINT32                                  MajorVersion;
  UINT32                                  MinorVersion;
  SHELLENV_ENABLE_PAGE_BREAK              EnablePageBreak;
  SHELLENV_DISABLE_PAGE_BREAK             DisablePageBreak;
  SHELLENV_GET_PAGE_BREAK                 GetPageBreak;

  SHELLENV_SET_KEY_FILTER                 SetKeyFilter;
  SHELLENV_GET_KEY_FILTER                 GetKeyFilter;

  SHELLENV_GET_EXECUTION_BREAK            GetExecutionBreak;
  SHELLENV_INCREMENT_SHELL_NESTING_LEVEL  IncrementShellNestingLevel;
  SHELLENV_DECREMENT_SHELL_NESTING_LEVEL  DecrementShellNestingLevel;
  SHELLENV_IS_ROOT_SHELL                  IsRootShell;

  SHELLENV_CLOSE_CONSOLE_PROXY            CloseConsoleProxy;
  HANDLE_ENUMERATOR                       HandleEnumerator;
  PROTOCOL_INFO_ENUMERATOR                ProtocolInfoEnumerator;
  GET_DEVICE_NAME                         GetDeviceName;
  GET_SHELL_MODE                          GetShellMode;
  SHELLENV_NAME_TO_PATH                   NameToPath;
  SHELLENV_GET_FS_NAME                    GetFsName;
  SHELLENV_FILE_META_ARG_NO_WILDCARD      FileMetaArgNoWildCard;
  SHELLENV_DEL_DUP_FILE                   DelDupFileArg;
  SHELLENV_GET_FS_DEVICE_PATH             GetFsDevicePath;
} EFI_SHELL_ENVIRONMENT2;

同一个文件中

/**
  Converts a device path into a file system map name.

  If DevPath is NULL, then ASSERT.

  This function looks through the shell environment map for a map whose device
  path matches the DevPath parameter.  If one is found the Name is returned via
  Name parameter.  If sucessful the caller must free the memory allocated for
  Name.

  This function will use the internal lock to prevent changes to the map during
  the lookup operation.

  @param[in] DevPath                The device path to search for a name for.
  @param[in] ConsistMapping         What state to verify map flag VAR_ID_CONSIST.
  @param[out] Name                  On sucessful return the name of that device path.

  @retval EFI_SUCCESS           The DevPath was found and the name returned
                                in Name.
  @retval EFI_OUT_OF_RESOURCES  A required memory allocation failed.
  @retval EFI_UNSUPPORTED       The DevPath was not found in the map.
**/
typedef
EFI_STATUS
(EFIAPI *SHELLENV_GET_FS_NAME) (
  IN EFI_DEVICE_PATH_PROTOCOL     * DevPath,
  IN BOOLEAN                      ConsistMapping,
  OUT CHAR16                      **Name
  );

根据上面的函数，编写程序如下

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

#include  <stdio.h>
#include  <stdlib.h>
#include  <wchar.h>

#include <Protocol/EfiShell.h>
#include <Library/ShellLib.h>

#include <Protocol/SimpleFileSystem.h>
#include <Protocol/BlockIo.h>
#include <Library/DevicePathLib.h>
#include <Library/HandleParsingLib.h>
#include <Library/SortLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/BaseMemoryLib.h>

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

extern EFI_SHELL_ENVIRONMENT2    *mEfiShellEnvironment2;
extern EFI_HANDLE				 gImageHandle;

EFI_STATUS
EFIAPI
PerformSingleMappingDisplay(
  IN CONST EFI_HANDLE Handle
  )
{
  EFI_DEVICE_PATH_PROTOCOL  *DevPath;
  EFI_DEVICE_PATH_PROTOCOL  *DevPathCopy;
  CHAR16                    *CurrentName;

  CurrentName = NULL;
  DevPath = DevicePathFromHandle(Handle);
  DevPathCopy = DevPath;
  mEfiShellEnvironment2->GetFsName(DevPathCopy,FALSE,&CurrentName);

  Print (L"%s \r\n", CurrentName);  
	
  if ((CurrentName) != NULL) { FreePool((CurrentName)); CurrentName = NULL; }

  return EFI_SUCCESS;
}

int
EFIAPI
main (                                         
  IN int Argc,
  IN char **Argv
  )
{
  EFI_STATUS                Status;
  EFI_HANDLE                *HandleBuffer=NULL;
  UINTN                     BufferSize=0;
  UINTN                     LoopVar;
  BOOLEAN                   Found;
  //Copy from ShellLibConstructorWorker in \ShellPkg\Library\UefiShellLib\UefiShellLib.c
  //
  // UEFI 2.0 shell interfaces (used preferentially)
  //
  Status = gBS->OpenProtocol(
    gImageHandle,
    &gEfiShellProtocolGuid,
    (VOID **)&gEfiShellProtocol,
    gImageHandle,
    NULL,
    EFI_OPEN_PROTOCOL_GET_PROTOCOL
   );
   
  if (EFI_ERROR(Status)) {
    //
    // Search for the shell protocol
    //
    Status = gBS->LocateProtocol(
      &gEfiShellProtocolGuid,
      NULL,
      (VOID **)&gEfiShellProtocol
     );
    if (EFI_ERROR(Status)) {
      gEfiShellProtocol = NULL;
     }
  }
  
  //
  // Look up all SimpleFileSystems in the platform
  //
  Status = gBS->LocateHandle(
    ByProtocol,
    &gEfiSimpleFileSystemProtocolGuid,
    NULL,
    &BufferSize,
    HandleBuffer);
	
  if (Status == EFI_BUFFER_TOO_SMALL) {
		HandleBuffer = AllocateZeroPool(BufferSize);
		if (HandleBuffer == NULL) {
			return (SHELL_OUT_OF_RESOURCES);
		}
		Status = gBS->LocateHandle(
			ByProtocol,
			&gEfiSimpleFileSystemProtocolGuid,
			NULL,
			&BufferSize,
			HandleBuffer);
   }

  //
  // Get the map name(s) for each one.
  //
  for ( LoopVar = 0, Found = FALSE
      ; LoopVar < (BufferSize / sizeof(EFI_HANDLE)) && HandleBuffer != NULL
      ; LoopVar ++
     ) {
    Status = PerformSingleMappingDisplay(HandleBuffer[LoopVar]);
    if (!EFI_ERROR(Status)) {
      Found = TRUE;
    }
  }
  
  FreePool(HandleBuffer);
	
  return EFI_SUCCESS;
}

运行结果，和 Map命令的对比

完整的代码下载
ShowMap

Step to UEFI (35） —– How to build Shell.efi

【特别提醒：下面的全部操作都是在UDK2014中完成，具体代码会与2010有差别】

第一个问题：我们运行的模拟环境（NT32）中的Shell是来自哪里？

回答：在 \Nt32Pkg\Nt32Pkg.fdf 中你可以看到下面的定义

################################################################################
#
# FILE statements are provided so that a platform integrator can include
# complete EFI FFS files, as well as a method for constructing FFS files
# using curly "{}" brace scoping. The following three FILEs are
# for binary shell, binary fat and logo module.
#
################################################################################
INF EdkShellBinPkg/FullShell/FullShell.inf

INF FatBinPkg/EnhancedFatDxe/Fat.inf

FILE FREEFORM = PCD(gEfiIntelFrameworkModulePkgTokenSpaceGuid.PcdLogoFile) {
    SECTION RAW = MdeModulePkg/Logo/Logo.bmp

如果你把上面的 FullShell.inf 替换成 EdkShellBinPkg\MinimumShell 下面的MinimumShell.inf 再次编译之后会发现使用的是Mini版本的Shell. 例如： Hexedit 这个命令只在Full版本中才有，Mini版本下不支持。(实验时候特别注意，如果你 Build了 MinimumShell.inf, 在 fsnt1: 下面有一个 Hexedit.efi)

2.如何重新Build Shell.efi?

根据 ShellBinPkg 目录下的 Readme.txt （没错，我也不知道为什么是在这个目录而不是ShellPkg下面的 ReadMe.txt） ,可以使用下面的命令进行Build:

build -a IA32 -p ShellPkg\ShellPkg.dsc -b RELEASE

3.实际操作。这是我们最常见到的Shell的模样，我下面要尝试给他添加一段String.

在 \ShellPkg\Application\Shell\Shell.c 可以看到输出版本信息的语句

    //
    // Display the version
    //
    if (!ShellInfoObject.ShellInitSettings.BitUnion.Bits.NoVersion) {
      ShellPrintHiiEx (
        0,
        gST->ConOut->Mode->CursorRow,
        NULL,
        STRING_TOKEN (STR_VER_OUTPUT_MAIN_SHELL),
        ShellInfoObject.HiiHandle,
        SupportLevel[PcdGet8(PcdShellSupportLevel)],
        gEfiShellProtocol->MajorVersion,
        gEfiShellProtocol->MinorVersion
       );

      ShellPrintHiiEx (
        -1,
        -1,
        NULL,
        STRING_TOKEN (STR_VER_OUTPUT_MAIN_SUPPLIER),
        ShellInfoObject.HiiHandle,
        (CHAR16 *) PcdGetPtr (PcdShellSupplier)
       );

      ShellPrintHiiEx (
        -1,
        -1,
        NULL,
        STRING_TOKEN (STR_VER_OUTPUT_MAIN_UEFI),
        ShellInfoObject.HiiHandle,
        (gST->Hdr.Revision&0xffff0000)>>16,
        (gST->Hdr.Revision&0x0000ffff),
        gST->FirmwareVendor,
        gST->FirmwareRevision
       );
    }

    //
    // Display the version
    //
    if (!ShellInfoObject.ShellInitSettings.BitUnion.Bits.NoVersion) {
      ShellPrintHiiEx (
        0,
        gST->ConOut->Mode->CursorRow,
        NULL,
        STRING_TOKEN (STR_VER_OUTPUT_MAIN_SHELL),
        ShellInfoObject.HiiHandle,
        SupportLevel[PcdGet8(PcdShellSupportLevel)],
        gEfiShellProtocol->MajorVersion,
        gEfiShellProtocol->MinorVersion
       );

      ShellPrintHiiEx (
        -1,
        -1,
        NULL,
        STRING_TOKEN (STR_VER_OUTPUT_MAIN_SUPPLIER),
        ShellInfoObject.HiiHandle,
        (CHAR16 *) PcdGetPtr (PcdShellSupplier)
       );

      ShellPrintHiiEx (
        -1,
        -1,
        NULL,
        STRING_TOKEN (STR_VER_OUTPUT_MAIN_UEFI),
        ShellInfoObject.HiiHandle,
        (gST->Hdr.Revision&0xffff0000)>>16,
        (gST->Hdr.Revision&0x0000ffff),
        gST->FirmwareVendor,
        gST->FirmwareRevision
       );
    }

	//LabZDebug_Start 加入我们定义的String
	ShellPrintHiiEx (
        -1,
        -1,
        NULL,
        STRING_TOKEN (STR_LABZ_UEFI),
        ShellInfoObject.HiiHandle
       );
	//LabZDebug_End

    //
    // Display the mapping
    //

    if (PcdGet8(PcdShellSupportLevel) >= 2 && !ShellInfoObject.ShellInitSettings.BitUnion.Bits.NoMap) {
      Status = RunCommand(L"map", NULL);
      ASSERT_EFI_ERROR(Status);
    }

同时在 \ShellPkg\Application\Shell\Shell.uni 加入我们自定义的字符串

#string STR_LABZ_UEFI		          #language en-US "www.lab-z.com 2014/12/12 build.....\r\n"

最后的结果如下，可以看到多出来一行我们自己定义的字符串：

特别提醒：请注意文章中两张图片，实际上盘符是有差别的，一个是 FSNTx: 一个是 FSx。就是说在虚拟环境下模拟出来的盘符还是有差别的。目前我不清楚这个差别是如何导致的。

========================================================================
2015年3月31日补充

1.build shell.efi 之后生成的文件在 Build\Shell\RELEASE_MYTOOLS\IA32下面。同样他的子目录中也能找到Shell.efi (总共三个)，他们内容相同

2.有一种情况是你替换了 Shell_Full.efi 之后，模拟器无法进入 shell,始终停留在Setup中。这种情况请检查输出的Log信息，我遇到的情况是因为改动有问题，导致 Shell.efi 是损坏的，无法正常Load起来。

Arduino Uno 的 Vin Pin

偶然注意到 Arduino Uno 上有个Vin Pin，但是AVR上没有对应的管脚，感觉比较奇怪，研究了一下。

原始图片来自【参考1】

这样的问题自然是要到电路图中查找答案。电路图和印刷版文件来自【参考2】

美中不足：虽然有PDF的电路图，但是不支持搜索，找了半天才在右上角找到

就是说Vin可以看作是DC输入的电压经过了一个二极管。因此，有两种情况：一是如果你插入了DC，那么Vin上会出现比DC稍微小一点的电压（因为经过了一个二极管）；第二种情况，可以直接从这里灌进去一个电压。猜测这样的设计可能是为了某些有供电能力的Shield考虑吧。

关于这部分，有一些介绍【参考2】

External (non-USB) power can come either from an AC-to-DC adapter (wall-wart) or battery. The adapter can be connected by plugging a 2.1mm center-positive plug into the board’s power jack. Leads from a battery can be inserted in the Gnd and Vin pin headers of the POWER connector.

再查看 PCB 文件

对照 Vin 可以看到，它是接U1的 3 Pin的。

U1是 NCP1117ST50T3,简单翻翻手册【参考3】，这是一个降压的IC，Pin 3是输入

因此，Vin是一个可以直接对板子供电，电器特性功能和板子上DC插孔类似的输入脚。

参考：

1.http://arduino.cc/en/uploads/Main/ArduinoUno_R3_Front.jpg

2.http://arduino.cc/en/Main/ArduinoBoardUno

3.http://wenku.baidu.com/view/f66976af284ac850ad0242b9.html NCP1117

4.http://solderpad.com/solderpad/arduino-uno/ Bom List特别注意上面的一些名称和原本电路图有差别。

Windows 7 64位下arduino驱动安装失败解决办法

最近入手一块 Arduino Micro Pro ，插在台式机上之后要求安装驱动，指定了 Arduino 目录下的 Drivers之后还出现了 Inf 段落无效的字样。忽然想起来我的 Win7 是Ghost版本，于是上网搜索解决办法。

在 http://blog.csdn.net/u013926582/article/details/24442583 和 http://www.arduino.cn/thread-2485-1-1.html 都有提到。

最后使用的方法是查看 C:\Windows\inf\setupapi.dev.log （要从下向上搜索，最近安装的错误在文件尾）

发现下面的字样

dvi: {DIF_INSTALLDEVICEFILES} 17:08:34.464
dvi: Class installer: Enter 17:08:34.465
dvi: Class installer: Exit
dvi: Default installer: Enter 17:08:34.465
dvi: {Install FILES}mdmcpq.inf
inf: Opened PNF: ‘c:\windows\system32\driverstore\filerepository\arduino.inf_amd64_neutral_844213a156728dfe\arduino.inf’ ([strings])
inf: Opened PNF: ‘C:\Windows\INF\mdmcpq.inf’ ([strings])
inf: Opened PNF: ‘C:\Windows\INF\usb.inf’ ([strings.0804])
inf: {Install Inf Section [DriverInstall]}
inf: CopyFiles=FakeModemCopyFileSection (arduino.inf line 128)
cpy: Open PnpLockdownPolicy: Err=2. This is OK. Use LockDownPolicyDefault
flq: QueueSingleCopy…
flq: Inf : ‘c:\windows\system32\driverstore\filerepository\arduino.inf_amd64_neutral_844213a156728dfe\arduino.inf’
! flq: Missing SourceDisksFiles/SourceDisksNames information from INF.
! flq: Default INBOX source locations pulled from pre-built DrvIndex
flq: SourceRootPath: ‘C:\Windows\System32\DriverStore\FileRepository\mdmcpq.inf_amd64_neutral_b53453733bd795bc’
flq: {FILE_QUEUE_COPY}
flq: CopyStyle – 0x00002000
flq: {FILE_QUEUE_COPY}
flq: CopyStyle – 0x00002000
flq: SourceRootPath – ‘C:\Windows\System32\DriverStore\FileRepository\mdmcpq.inf_amd64_neutral_b53453733bd795bc’
flq: SourcePath – ‘\’
flq: SourceFilename – ‘usbser.sys’
flq: TargetDirectory- ‘C:\Windows\system32\DRIVERS’
flq: TargetFilename – ‘usbser.sys’
flq: {FILE_QUEUE_COPY exit(0x00000000)}
flq: {FILE_QUEUE_COPY exit(0x00000000)}
inf: {Install Inf Section [DriverInstall] exit (0x00000000)}
dvi: Processing co-installer registration section [DriverInstall.CoInstallers].
inf: {Install Inf Section [DriverInstall.CoInstallers]}
inf: {Install Inf Section [DriverInstall.CoInstallers] exit (0x00000000)}
dvi: Co-installers registered.
dvi: {Install INTERFACES}
dvi: Installing section [DriverInstall.Interfaces]
dvi: {Install INTERFACES exit 00000000}
dvi: {Install FILES exit (0x00000000)}
dvi: Default installer: Exit
dvi: {DIF_INSTALLDEVICEFILES – exit(0x00000000)} 17:08:34.479
ndv: Pruning file queue…
dvi: {_SCAN_FILE_QUEUE}
flq: ScanQ flags=620
flq: SPQ_SCAN_PRUNE_COPY_QUEUE
flq: SPQ_SCAN_FILE_COMPARISON
flq: SPQ_SCAN_ACTIVATE_DRP
flq: ScanQ number of copy nodes=1
! sig: GetNameSDInfo
! sig: Error 0: The operation completed successfully.
flq: ScanQ action=200 DoPruning=32
flq: ScanQ end Validity flags=620 CopyNodes=1
dvi: {_SCAN_FILE_QUEUE exit(0, 0x00000000)}
ndv: Committing file queue…
flq: {_commit_file_queue}
flq: CommitQ DelNodes=0 RenNodes=0 CopyNodes=1
flq: {SPFILENOTIFY_STARTQUEUE}
flq: {SPFILENOTIFY_STARTQUEUE – exit(0x00000001)}
flq: {_commit_copy_subqueue}
flq: subqueue count=1
flq: {SPFILENOTIFY_STARTSUBQUEUE}
flq: {SPFILENOTIFY_STARTSUBQUEUE – exit(0x00000001)}
flq: source media:
flq: SourcePath – [C:\Windows\System32\DriverStore\FileRepository\mdmcpq.inf_amd64_neutral_b53453733bd795bc]
flq: SourceFile – [usbser.sys]
flq: Flags – 0x00000000
flq: {SPFQNOTIFY_NEEDMEDIA}
flq: {SPFILENOTIFY_NEEDMEDIA}
flq: {SPFILENOTIFY_NEEDMEDIA – exit(0x00000000)}
flq: {SPFQNOTIFY_NEEDMEDIA – returned 0x00000000}
!!! flq: source media: SPFQOPERATION_ABORT.
!!! flq: Error 2: The system cannot find the file specified.
flq: {_commit_copy_subqueue exit(0x00000002)}
!!! flq: FileQueueCommit aborting!
!!! flq: Error 2: The system cannot find the file specified.
flq: {SPFILENOTIFY_ENDQUEUE}
flq: {SPFILENOTIFY_ENDQUEUE – exit(0x00000001)}
flq: {_commit_file_queue exit(0x00000002)}
ndv: Device install status=0x00000002
ndv: Performing device install final cleanup…
! ndv: Queueing up error report since device installation failed…
ndv: {Core Device Install – exit(0x00000002)} 17:08:34.493
dvi: {DIF_DESTROYPRIVATEDATA} 17:08:34.494
dvi: Class installer: Enter 17:08:34.494
dvi: Class installer: Exit

错误是说找不到 C:\Windows\System32\DriverStore\FileRepository\mdmcpq.inf_amd64_neutral_b53453733bd795bc（特别注意，不同系统，这个名字会不同，需要根据你当前系统中的错误来确定）我进去 C:\Windows\System32\DriverStore\FileRepository\ 一看确实没有。

又在网上搜索了一下，在 http://www.arduino.cn/thread-2350-1-1.html 这里给出来两个64位的。

下载之后，首先将 UsbSer.sys 放到 Windows\System32\Drivers 下面，然后在 C:\Windows\System32\DriverStore\FileRepository\ 下面创建一个 mdmcpq.inf_amd64_neutral_b53453733bd795bc 目录把mdmcpq.zip中的全部内容放进去。

卸载之前安装的驱动，然后重新安装一次即可。

usbser

mdmcpq.inf

如果有遇到同样问题的朋友可以试试。

===========================================================================
2月16日如果始终无法完成安装，建议检查一下你是否将设备插在 USB 3.0 的Port上。某些USB 3.0的 Controller 对于一些低速设备存在兼容性问题。如果是的话，请更换到 USB 2.0 的端口上再进行上述实验。

4月4日在FileRepository 目录下创建目录的过程中，可能遇到“需要权限来执行此操作”的问题。解决方法是：

1.确保你的杀毒软件关闭了（比如，瑞星之类的你可以考虑直接卸载）
2.在FileRepository 目录上点鼠标右键，弹出的菜单上切换到安全页面。然后在上面的组或用户名栏目上检查是否有你当前账户。比如：开机登录的用户名是 player ，而这里没有。那么按下编辑键，在新弹出页面上用添加按钮，然后输入 player ，按下检查名称按钮就添加进去了。特别注意：其中的 SYSTEM 用户名，并非 Administrator,如果你是 Administrator 登录进来，那么需要手工添加一下。

Step to UEFI (34） —– FindFile2 查找特定文件

前面介绍了如何枚举全部文件，这里介绍一下如何枚举特定的问题。比如，用 “M*.*” 匹配全部 M开头的文件。

参考 touch 命令的Source Code 很快有了方案，使用：ShellOpenFileMetaArg

对应的头文件在 \ShellPkg\Include\Library\ShellLib.h

/**
  Opens a group of files based on a path.

  This function uses the Arg to open all the matching files. Each matched
  file has a SHELL_FILE_ARG structure to record the file information. These
  structures are placed on the list ListHead. Users can get the SHELL_FILE_ARG
  structures from ListHead to access each file. This function supports wildcards
  and will process '?' and '*' as such.  The list must be freed with a call to
  ShellCloseFileMetaArg().

  If you are NOT appending to an existing list *ListHead must be NULL.  If
  *ListHead is NULL then it must be callee freed.

  @param[in] Arg                 The pointer to path string.
  @param[in] OpenMode            Mode to open files with.
  @param[in, out] ListHead       Head of linked list of results.

  @retval EFI_SUCCESS           The operation was sucessful and the list head
                                contains the list of opened files.
  @retval != EFI_SUCCESS        The operation failed.

  @sa InternalShellConvertFileListType
**/
EFI_STATUS
EFIAPI
ShellOpenFileMetaArg (
  IN CHAR16                     *Arg,
  IN UINT64                     OpenMode,
  IN OUT EFI_SHELL_FILE_INFO    **ListHead
  );

从介绍上来看，最主要的参数有2个：Arg输入要查找的路径，可以使用通配符。ListHead 返回结果。结果实际上是两部分一部分是 SHELL_FILE_ARG 结构体，另外一部分是 EFI_SHELL_FILE_INFO 结构体。前者只有一个，后者有一个或者很多个。他们使用链表结构联系在一起。上面这样的结构体感觉上很奇怪，不过确实是这样的。可以在Touch的 Source Code中看到。他使用 GetFirstNode 来跳过第一个不需要的结构体。这个函数可以在 \MdePkg\Library\BaseLib\LinkedList.c 里面看到

/**
  Retrieves the first node of a doubly-linked list.

  Returns the first node of a doubly-linked list.  List must have been 
  initialized with INTIALIZE_LIST_HEAD_VARIABLE() or InitializeListHead().
  If List is empty, then List is returned.

  If List is NULL, then ASSERT().
  If List was not initialized with INTIALIZE_LIST_HEAD_VARIABLE() or 
  InitializeListHead(), then ASSERT().
  If PcdMaximumLinkedListLenth is not zero, and the number of nodes
  in List, including the List node, is greater than or equal to
  PcdMaximumLinkedListLength, then ASSERT().

  @param  List  A pointer to the head node of a doubly-linked list.

  @return The first node of a doubly-linked list.
  @retval NULL  The list is empty.

**/
LIST_ENTRY *
EFIAPI
GetFirstNode (
  IN      CONST LIST_ENTRY          *List
  )
{
  //
  // ASSERT List not too long
  //
  ASSERT (InternalBaseLibIsNodeInList (List, List, FALSE));

  return List->ForwardLink;
}

最终编写程序如下

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

#include  <stdio.h>
#include  <stdlib.h>
#include  <wchar.h>

#include <Protocol/EfiShell.h>
#include <Library/ShellLib.h>

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

extern EFI_SHELL_PROTOCOL        *gEfiShellProtocol;

void PrintShellFileInfo(EFI_SHELL_FILE_INFO     *ShellFileInfo)
{
  //Print(L"Status [%d]\n",ShellFileInfo-> Status);
  Print(L"FullName [%s]\n",ShellFileInfo-> FullName);
  //Print(L"FileName [%s]\n",ShellFileInfo-> FileName);
  //Print(L"Handle [%d]\n",ShellFileInfo->Handle);  
}

int
EFIAPI
main (                                         
  IN int Argc,
  IN char **Argv
  )
{
  //EFI_FILE_HANDLE   DirHandle;
  RETURN_STATUS     Status;
  EFI_SHELL_FILE_INFO *FileList=NULL;
  EFI_SHELL_FILE_INFO *Node;
  
  Status = ShellOpenFileMetaArg(L"fsnt0:\\a*.*", EFI_FILE_MODE_READ, &FileList);
  if(Status != RETURN_SUCCESS) {
        Print(L"OpenFile failed!\n");
		return EFI_SUCCESS;
  }							   
  
  //Print(L"Signature [%X]\n",((SHELL_FILE_ARG *)&FileList)->Signature);  
  //Print(L"Status []\n",((SHELL_FILE_ARG *)&FileList)->Status);  
  //Print(L"ParentName [%s]\n",((SHELL_FILE_ARG *)&FileList)->ParentName);  
  //Print(L"FullName [%s]\n",((SHELL_FILE_ARG *)&FileList)->FullName);  
  //Print(L"FileName [%s]\n",((SHELL_FILE_ARG *)&FileList)->FileName);  

  
  // check that we have at least 1 file
  //
  if (FileList == NULL || IsListEmpty(&FileList->Link)) {
                Print(L"No Files Found!\n");
  } else {
		//
		// loop through the list and make sure we are not aborting...
		//
		for ( Node = (EFI_SHELL_FILE_INFO*)GetFirstNode(&FileList->Link)
			; !IsNull(&FileList->Link, &Node->Link) && !ShellGetExecutionBreakFlag()
			; Node = (EFI_SHELL_FILE_INFO*)GetNextNode(&FileList->Link, &Node->Link)){
					PrintShellFileInfo(Node);			   
				//
				// make sure the file opened ok
				//
				if (EFI_ERROR(Node->Status)){
					Print(L"OpenFile Error!\n");
				}

        }
    }
		  
   //
   // Free the fileList
   //
   if (FileList != NULL && !IsListEmpty(&FileList->Link)) {
       Status = ShellCloseFileMetaArg(&FileList);
   }
   FileList = NULL;
		
  return EFI_SUCCESS;
}

运行结果

可以看出能够正常查找到我们需要的 fsnt0:x下面a开头的文件。

代码下载

FindFile2

===============================================================================
最后有一个问题：
前面说过，ShellOpenFileMetaArg 输出的结果是2部分组成的，我的程序只是输出了后面的那个结构体，那么前面的那个结构体呢？

  Status = ShellOpenFileMetaArg(L"fsnt0:\\a*.*", EFI_FILE_MODE_READ, &FileList);
  if(Status != RETURN_SUCCESS) {
        Print(L"OpenFile failed!\n");
		return EFI_SUCCESS;
  }							   
  
  Print(L"Signature [%X]\n",((SHELL_FILE_ARG *)&FileList)->Signature);  
  Print(L"Status []\n",((SHELL_FILE_ARG *)&FileList)->Status);  
  Print(L"ParentName [%s]\n",((SHELL_FILE_ARG *)&FileList)->ParentName);  
  Print(L"FullName [%s]\n",((SHELL_FILE_ARG *)&FileList)->FullName);  
  Print(L"FileName [%s]\n",((SHELL_FILE_ARG *)&FileList)->FileName);

结果出来之后非常奇怪的是 Signature 的输出并非固定的数值，而根据 EfiShellEnvironment2.h 来看，这个似乎应该是一个固定的值。

不知道是我理解有偏差还是输出方法不对。有懂的朋友请指教一下。谢谢！

Step to UEFI (33） —– FindFile 枚举目录下所有文件

研究一下如何枚举目录下的全部文件，查到了2个函数 ShellFindFirstFile 和 ShellFindNextFile。下面就研究如何使用这两个函数。

这两个函数在 \ShellPkg\Include\Library\ShellLib.h 中有定义

/** Retrieve first entry from a directory.

  This function takes an open directory handle and gets information from the
  first entry in the directory.  A buffer is allocated to contain
  the information and a pointer to the buffer is returned in *Buffer.  The
  caller can use ShellFindNextFile() to get subsequent directory entries.

  The buffer will be freed by ShellFindNextFile() when the last directory
  entry is read.  Otherwise, the caller must free the buffer, using FreePool,
  when finished with it.

  @param[in]  DirHandle         The file handle of the directory to search.
  @param[out] Buffer            The pointer to the buffer for the file's information.

  @retval EFI_SUCCESS           Found the first file.
  @retval EFI_NOT_FOUND         Cannot find the directory.
  @retval EFI_NO_MEDIA          The device has no media.
  @retval EFI_DEVICE_ERROR      The device reported an error.
  @retval EFI_VOLUME_CORRUPTED  The file system structures are corrupted.
  @return Others                Status of ShellGetFileInfo, ShellSetFilePosition,
                                or ShellReadFile.

  @sa ShellReadFile
**/
EFI_STATUS
EFIAPI
ShellFindFirstFile (
  IN      SHELL_FILE_HANDLE       DirHandle,
     OUT  EFI_FILE_INFO         **Buffer
  );


/** Retrieve next entries from a directory.

  To use this function, the caller must first call the ShellFindFirstFile()
  function to get the first directory entry.  Subsequent directory entries are
  retrieved by using the ShellFindNextFile() function.  This function can
  be called several times to get each entry from the directory.  If the call of
  ShellFindNextFile() retrieved the last directory entry, the next call of
  this function will set *NoFile to TRUE and free the buffer.

  @param[in]  DirHandle         The file handle of the directory.
  @param[out] Buffer            The pointer to buffer for file's information.
  @param[out] NoFile            The pointer to boolean when last file is found.

  @retval EFI_SUCCESS           Found the next file, or reached last file
  @retval EFI_NO_MEDIA          The device has no media.
  @retval EFI_DEVICE_ERROR      The device reported an error.
  @retval EFI_VOLUME_CORRUPTED  The file system structures are corrupted.
**/
EFI_STATUS
EFIAPI
ShellFindNextFile(
  IN SHELL_FILE_HANDLE                      DirHandle,
  OUT EFI_FILE_INFO              *Buffer,
  OUT BOOLEAN                    *NoFile
  )
{
  //
  // pass to file handle lib
  //
  return (FileHandleFindNextFile(DirHandle, Buffer, NoFile));
}

阅读说明可以发现，调用之后会分配一个Buffer,然后由调用者来负责释放。

开始写程序之后很快问题就来了，下面这样很简单的程序会让我的模拟器一次次崩溃。

int
EFIAPI
main (
  IN int Argc,
  IN char **Argv
  )
{
  EFI_FILE_HANDLE   DirHandle;
  RETURN_STATUS     Status;
  EFI_FILE_INFO     *FileInfo = NULL;
  BOOLEAN			NoFile=FALSE;
  
  Status = ShellOpenFileByName(L"fsnt0:\\testz", (SHELL_FILE_HANDLE *)&DirHandle,
                               EFI_FILE_MODE_READ , 0);

  if(Status != RETURN_SUCCESS) {
        Print(L"OpenFile failed!\n");
		return EFI_SUCCESS;
      }							   

  ShellFindFirstFile(DirHandle,&FileInfo);
  PrintFileInfo(FileInfo);
  free(FileInfo);
  while (FALSE==NoFile) 
    {
		Status=ShellFindNextFile(DirHandle,FileInfo,&NoFile);
		if (EFI_SUCCESS == Status)
			{
			}
		Print(L"No File[%d]\n",NoFile);	
	}
 
  return EFI_SUCCESS;
}

百思不得其解，在程序中加入输出函数，跟踪一下。出错的部分在ShellFindNextFile(DirHandle,FileInfo,&NoFile); 中。追踪进入 \ShellPkg\Library\UefiFileHandleLib\UefiFileHandleLib.c 的 FileHandleFindNextFile。

/** Retrieve next entries from a directory.

  To use this function, the caller must first call the FileHandleFindFirstFile()
  function to get the first directory entry.  Subsequent directory entries are
  retrieved by using the FileHandleFindNextFile() function.  This function can
  be called several times to get each entry from the directory.  If the call of
  FileHandleFindNextFile() retrieved the last directory entry, the next call of
  this function will set *NoFile to TRUE and free the buffer.

  @param[in]  DirHandle         The file handle of the directory.
  @param[out] Buffer            The pointer to buffer for file's information.
  @param[out] NoFile            The pointer to boolean when last file is found.

  @retval EFI_SUCCESS           Found the next file, or reached last file
  @retval EFI_NO_MEDIA          The device has no media.
  @retval EFI_DEVICE_ERROR      The device reported an error.
  @retval EFI_VOLUME_CORRUPTED  The file system structures are corrupted.
**/
EFI_STATUS
EFIAPI
FileHandleFindNextFile(
  IN EFI_FILE_HANDLE          DirHandle,
  OUT EFI_FILE_INFO          *Buffer,
  OUT BOOLEAN                *NoFile
  )
{
  EFI_STATUS    Status;
  UINTN         BufferSize;

  //
  // ASSERTs for DirHandle or Buffer or NoFile poitners being NULL
  //
  ASSERT (DirHandle != NULL);
  ASSERT (Buffer    != NULL);
  ASSERT (NoFile    != NULL);

  //
  // This BufferSize MUST stay equal to the originally allocated one in GetFirstFile
  //
  BufferSize = FIND_XXXXX_FILE_BUFFER_SIZE;

  //
  // read in the info about the next file
  //
  Status = FileHandleRead (DirHandle, &BufferSize, Buffer);
  ASSERT(Status != EFI_BUFFER_TOO_SMALL);
  if (EFI_ERROR(Status)) {
    return (Status);
  }

  //
  // If we read 0 bytes (but did not have erros) we already read in the last file.
  //
  if (BufferSize == 0) {
    FreePool(Buffer);
    *NoFile = TRUE;
  }

  return (EFI_SUCCESS);
}

确定是 FreePool(Buffer); 导致的。看到这个代码感觉很奇怪，明明是让 caller 负责释放，为什么他在里面要干这事情？再阅读函数说明“ If the call of
FileHandleFindNextFile() retrieved the last directory entry, the next call of
this function will set *NoFile to TRUE and free the buffer.” 原来这个函数设计的意思是：调用FileHandleFindNextFile 不断取得文件时，如果你中间停止了，那么请自行释放Buffer；但是如果你一直调用到了最后一个文件，那么函数本身会帮你释放掉而不需要你来做。

最终的程序不复杂

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

#include  <stdio.h>
#include  <stdlib.h>
#include  <wchar.h>

#include <Protocol/EfiShell.h>
#include <Library/ShellLib.h>

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

extern EFI_SHELL_PROTOCOL        *gEfiShellProtocol;

void PrintFileInfo(EFI_FILE_INFO     *FileInfo)
{
  Print(L"Filesize [%ld] bytes\n",FileInfo-> FileSize);
  Print(L"PhysicalSize [%ld] bytes\n",FileInfo-> PhysicalSize);  

  Print(L"File Create date [%d-%d-%d %d-%d-%d]\n",
		FileInfo-> CreateTime.Year,
		FileInfo-> CreateTime.Month,
		FileInfo-> CreateTime.Day,
		FileInfo-> CreateTime.Hour,
		FileInfo-> CreateTime.Minute,
		FileInfo-> CreateTime.Second);    
		
  Print(L"File last accessed date [%d-%d-%d %d-%d-%d]\n",
		FileInfo-> LastAccessTime.Year,
		FileInfo-> LastAccessTime.Month,
		FileInfo-> LastAccessTime.Day,
		FileInfo-> LastAccessTime.Hour,
		FileInfo-> LastAccessTime.Minute,
		FileInfo-> LastAccessTime.Second);   		
		
  Print(L"File last modification date [%d-%d-%d %d-%d-%d]\n",
		FileInfo-> ModificationTime.Year,
		FileInfo-> ModificationTime.Month,
		FileInfo-> ModificationTime.Day,
		FileInfo-> ModificationTime.Hour,
		FileInfo-> ModificationTime.Minute,
		FileInfo-> ModificationTime.Second);   		

  Print(L"File Name [%s]\n",&FileInfo->FileName[0]);  
}

int
EFIAPI
main (
  IN int Argc,
  IN char **Argv
  )
{
  EFI_FILE_HANDLE   DirHandle;
  RETURN_STATUS     Status;
  EFI_FILE_INFO     *FileInfo = NULL;
  BOOLEAN			NoFile=FALSE;
  
  Status = ShellOpenFileByName(L"fsnt0:", (SHELL_FILE_HANDLE *)&DirHandle,
                               EFI_FILE_MODE_READ , 0);

  if(Status != RETURN_SUCCESS) {
        Print(L"OpenFile failed!\n");
		return EFI_SUCCESS;
      }							   

  ShellFindFirstFile(DirHandle,&FileInfo);
  while (TRUE!=NoFile) 
    {
	    PrintFileInfo(FileInfo);
		Status=ShellFindNextFile(DirHandle,FileInfo,&NoFile);
	}
  return EFI_SUCCESS;
}

运行结果

完整代码下载

FindFile

Step to UEFI (32） —– GetFileInfo

这里介绍一个能够获得文件基本信息的函数： GetFileInfo

可以在 \ShellPkg\Include\Library\ShellLib.h 看到定义

/**
  This function will retrieve the information about the file for the handle
  specified and store it in allocated pool memory.

  This function allocates a buffer to store the file's information. It is the
  caller's responsibility to free the buffer.

  @param[in] FileHandle         The file handle of the file for which information is
                                being requested.

  @retval NULL                  Information could not be retrieved.

  @return                       The information about the file.
**/
EFI_FILE_INFO*
EFIAPI
ShellGetFileInfo (
  IN SHELL_FILE_HANDLE          FileHandle
  );

需要FileHandle作为输入函数，输出结果是 EFI_FILE_INFO 结构体。这个结构体可以在
\MdePkg\Include\Guid\FileInfo.h 这个文件中看到(同时在 \EdkCompatibilityPkg\Foundation\Efi\Protocol\FileInfo\FileInfo.h 里面也有一个定义，只是这个定义未参加编译)。需要注意，调用的函数负责给结果分配一块内存，你自己的程序要负责释放这块内存的。

typedef struct {
  ///
  /// The size of the EFI_FILE_INFO structure, including the Null-terminated FileName string.
  ///
  UINT64    Size;
  ///
  /// The size of the file in bytes.
  ///
  UINT64    FileSize;
  ///
  /// PhysicalSize The amount of physical space the file consumes on the file system volume.
  ///
  UINT64    PhysicalSize;
  ///
  /// The time the file was created.
  ///
  EFI_TIME  CreateTime;
  ///
  /// The time when the file was last accessed.
  ///
  EFI_TIME  LastAccessTime;
  ///
  /// The time when the file's contents were last modified.
  ///
  EFI_TIME  ModificationTime;
  ///
  /// The attribute bits for the file.
  ///
  UINT64    Attribute;
  ///
  /// The Null-terminated name of the file.
  ///
  CHAR16    FileName[1];
} EFI_FILE_INFO;

看这个结构体可以得知，我们能够获得文件的大小，创建时间，修改时间属性文件名等等。

对于时间的定义 EFI_TIME 可以在 \BaseTools\Source\C\Include\Common\UefiBaseTypes.h 看到。相比之前我们看过的 time_t ,这个结构体是很单纯的定义，不需要换算：

// EFI Time Abstraction:
//  Year:       2000 - 20XX
//  Month:      1 - 12
//  Day:        1 - 31
//  Hour:       0 - 23
//  Minute:     0 - 59
//  Second:     0 - 59
//  Nanosecond: 0 - 999,999,999
//  TimeZone:   -1440 to 1440 or 2047
//
typedef struct {
  UINT16  Year;
  UINT8   Month;
  UINT8   Day;
  UINT8   Hour;
  UINT8   Minute;
  UINT8   Second;
  UINT8   Pad1;
  UINT32  Nanosecond;
  INT16   TimeZone;
  UINT8   Daylight;
  UINT8   Pad2;
} EFI_TIME;

对于 Attribute 的定义，在 \MdePkg\Include\Protocol\SimpleFileSystem.h

//
// File attributes
//
#define EFI_FILE_READ_ONLY  0x0000000000000001ULL
#define EFI_FILE_HIDDEN     0x0000000000000002ULL
#define EFI_FILE_SYSTEM     0x0000000000000004ULL
#define EFI_FILE_RESERVED   0x0000000000000008ULL
#define EFI_FILE_DIRECTORY  0x0000000000000010ULL
#define EFI_FILE_ARCHIVE    0x0000000000000020ULL
#define EFI_FILE_VALID_ATTR 0x0000000000000037ULL

最后，写一个程序验证一下

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

#include  <stdio.h>
#include  <stdlib.h>
#include  <wchar.h>

#include <Protocol/EfiShell.h>
#include <Library/ShellLib.h>

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

extern EFI_SHELL_PROTOCOL        *gEfiShellProtocol;

int
EFIAPI
main (
  IN int Argc,
  IN char **Argv
  )
{
  EFI_FILE_HANDLE   FileHandle;
  RETURN_STATUS     Status;
  EFI_FILE_INFO     *FileInfo = NULL;
  
  Status = ShellOpenFileByName(L"fsnt0:", (SHELL_FILE_HANDLE *)&FileHandle,
                               EFI_FILE_MODE_READ , 0);

  if(Status != RETURN_SUCCESS) {
        Print(L"OpenFile failed!\n");
		return EFI_SUCCESS;
      }							   

  FileInfo = ShellGetFileInfo( (SHELL_FILE_HANDLE)FileHandle);	

  Print(L"Filesize [%ld] bytes\n",FileInfo-> FileSize);
  Print(L"PhysicalSize [%ld] bytes\n",FileInfo-> PhysicalSize);  

  Print(L"File Create date [%d-%d-%d %d-%d-%d]\n",
		FileInfo-> CreateTime.Year,
		FileInfo-> CreateTime.Month,
		FileInfo-> CreateTime.Day,
		FileInfo-> CreateTime.Hour,
		FileInfo-> CreateTime.Minute,
		FileInfo-> CreateTime.Second);    
		
  Print(L"File last accessed date [%d-%d-%d %d-%d-%d]\n",
		FileInfo-> LastAccessTime.Year,
		FileInfo-> LastAccessTime.Month,
		FileInfo-> LastAccessTime.Day,
		FileInfo-> LastAccessTime.Hour,
		FileInfo-> LastAccessTime.Minute,
		FileInfo-> LastAccessTime.Second);   		
		
  Print(L"File last modification date [%d-%d-%d %d-%d-%d]\n",
		FileInfo-> ModificationTime.Year,
		FileInfo-> ModificationTime.Month,
		FileInfo-> ModificationTime.Day,
		FileInfo-> ModificationTime.Hour,
		FileInfo-> ModificationTime.Minute,
		FileInfo-> ModificationTime.Second);   		

  Print(L"File Name [%s]\n",&FileInfo->FileName[0]);  
		
  free(FileInfo);  // Free up the buffer from ShellGetFileInfo()  
  
  return EFI_SUCCESS;
}

代码下载：
GetFileInfo

参考：

1.本文的例子参考 \ShellPkg\Library\UefiShellLevel3CommandsLib\Touch.c