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一个让你轻松配置ESP32 WIFI的库

ESP32 带有 WIFI 功能，而众所周知要想让一个设备连接WIFI AP 需要告知设备对应 AP 的名称和密码，简单实验的话，可以直接在代码中写死这两个参数，但这种情况下烧写之后设备只能在固定的环境下使用。https://github.com/tzapu/wifimanager 这个项目可以解决上述问题。先说一下这个东西如何使用:

编译下载Arduino\libraries\WiFiManager-master\examples\OnDemand下面的代码
上电运行之后短接 Pin0
用手机查找OnDemandAP 这个 AP
连接之后自动打开下面的界面

5.选择 Configure WIFI 会显示当前能搜索到的WIFI AP名称，选择你要的

6.输入对应的密码设备即可连接

我在 DFRobot的 FireBeetle 上实验（需要注意他自带的WIFI库太老，运行期AP 无法启动，需要用ESP32 Arduino库中的 FireBeetle），工作正常。

WiFiManager-master 下载

Step to UEFI (263）实验：直接修改QEMU的启动顺序

当我们使用如下 Command 启动 QEMU 的时候，能够将 d:\tmp 目录映射为 fs0:

.\qemu-system-x86_64.exe -bios ovmf.fd  -hda fat:rw:d:\tmp\

之后，可以在这个目录中看到一个名为 NvVars 的文件。这次实验的目标是直接修改 NvVars 文件来实现调整启动顺序。例如：启动之后在 Setup 中可以看到如下4个启动设备：

1.进入Shell 后使读取变量的命令，将变量保存在 Result.txt 文件中：

Dmpstore >> result.txt

2.在 Debug Log 中可以看到如下字样，就是说 OVMF 在启动过程中会读取NvVars这个文件作为变量：

InstallProtocolInterface: 964E5B22-6459-11D2-8E39-00A0C969723B 6B6F030
Installed Fat filesystem on 6C14698
FsAccess.c: LoadNvVarsFromFs
FSOpen: Open 'NvVars' Success
FsAccess.c: Read 10590 bytes from NV Variables file

3.进一步分析，读取动作来自 ovmfpkg\library\nvvarsfilelib\FsAccess.c 文件中的LoadNvVarsFromFs() 函数

/**
  Loads the non-volatile variables from the NvVars file on the
  given file system.
 
  @param[in]  FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance
 
  @return     EFI_STATUS based on the success or failure of load operation
 
**/
EFI_STATUS
LoadNvVarsFromFs (
  EFI_HANDLE                            FsHandle
  )

4.具体读取动作在ReadNvVarsFile() 函数中：

/**
  Reads the contents of the NvVars file on the file system
 
  @param[in]  FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance
 
  @return     EFI_STATUS based on the success or failure of the file read
 
**/
EFI_STATUS
ReadNvVarsFile (
  IN  EFI_HANDLE            FsHandle
  )

读取内容

FileContents = FileHandleReadToNewBuffer (File, FileSize);
if (FileContents == NULL) {
  FileHandleClose (File);
  return EFI_UNSUPPORTED;
}

5.读取之后使用 IterateVariablesInBuffer() 函数进行解析

/**
  Iterates through the variables in the buffer, and calls a callback
  function for each variable found.
 
  @param[in]  CallbackFunction - Function called for each variable instance
  @param[in]  Context - Passed to each call of CallbackFunction
  @param[in]  Buffer - Buffer containing serialized variables
  @param[in]  MaxSize - Size of Buffer in bytes
 
  @return     EFI_STATUS based on the success or failure of the operation
 
**/
STATIC
EFI_STATUS
IterateVariablesInBuffer (
  IN VARIABLE_SERIALIZATION_ITERATION_CALLBACK  CallbackFunction,
  IN VOID                                       *CallbackContext,
  IN VOID                                       *Buffer,
  IN UINTN                                      MaxSize
  )

上面是一些基本的研究，下面尝试直接修改。在Dump 的变量文件Result.txt 中，可以看到 BootOrder 变量：

00000080: 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00  *................*
  00000090: 00 00 00 00 7F FF 04 00-4E AC 08 81 11 9F 59 4D  *........N.....YM*
  000000A0: 85 0E E2 1A 52 2C 59 B2-                         *....R,Y.*
Variable NV+RT+BS 'EFIGlobalVariable:BootOrder' DataSize = 0x0A
  00000000: 00 00 01 00 02 00 03 00-04 00                    *..........*
Variable NV+RT+BS 'EFIGlobalVariable:Key0002' DataSize = 0x0E
  00000000: 00 00 00 40 3C 4A 2D 14-05 00 11 00 00 00        *...@&lt;J-.......*

对应在 NvVars 文件中位于下面几行：

这里，将 00 00 01 00 02 00 03 00-04 00 修改为 00 00 04 00 02 00 03 00-01 00，下次再启动 QEMU 会会先启动到网卡上了。

Step to UEFI (262）给 QEMU 的 BIOS 增加 BootMenu快捷键

在实验中，我发现 QEMU 启动的虚拟机并不支持调出 BootMenu，为此研究一下如何修改BIOS 添加这个功能。

前面的实验中，我们在启动项目中插入了自定义的 Application，主要代码在BdsPlatform.c 中。继续查看这个文件，可以看到分配快捷键的代码：

VOID
PlatformRegisterOptionsAndKeys (
  VOID
  )
{
  EFI_STATUS                   Status;
  EFI_INPUT_KEY                Enter;
  EFI_INPUT_KEY                F2;
  EFI_INPUT_KEY                Esc;
  EFI_BOOT_MANAGER_LOAD_OPTION BootOption;
 
  //
  // Register ENTER as CONTINUE key
  //
  Enter.ScanCode    = SCAN_NULL;
  Enter.UnicodeChar = CHAR_CARRIAGE_RETURN;
  Status = EfiBootManagerRegisterContinueKeyOption (0, &amp;Enter, NULL);
  ASSERT_EFI_ERROR (Status);
 
  //
  // Map F2 to Boot Manager Menu
  //
  F2.ScanCode     = SCAN_F2;
  F2.UnicodeChar  = CHAR_NULL;
  Esc.ScanCode    = SCAN_ESC;
  Esc.UnicodeChar = CHAR_NULL;
  Status = EfiBootManagerGetBootManagerMenu (&amp;BootOption);
  ASSERT_EFI_ERROR (Status);
  Status = EfiBootManagerAddKeyOptionVariable (
             NULL, (UINT16) BootOption.OptionNumber, 0, &amp;F2, NULL
             );
  ASSERT (Status == EFI_SUCCESS || Status == EFI_ALREADY_STARTED);
  Status = EfiBootManagerAddKeyOptionVariable (
             NULL, (UINT16) BootOption.OptionNumber, 0, &amp;Esc, NULL
             );
  ASSERT (Status == EFI_SUCCESS || Status == EFI_ALREADY_STARTED);
}

和EmulatorPkg 中的PlatformBdsRegisterStaticBootOptions() 函数进行对比（代码位于 \EmulatorPkg\Library\PlatformBmLib\PlatformBm.c中），可以看到后者注册了多个快捷键对应着不同的功能：

/**
  Register the static boot options.
**/
VOID
PlatformBdsRegisterStaticBootOptions (
  VOID
  )
{
  EFI_GRAPHICS_OUTPUT_BLT_PIXEL  Black;
  EFI_GRAPHICS_OUTPUT_BLT_PIXEL  White;
  EFI_INPUT_KEY                  Enter;
  EFI_INPUT_KEY                  F2;
  EFI_INPUT_KEY                  F7;
  EFI_BOOT_MANAGER_LOAD_OPTION   BootOption;
  UINTN                          OptionNumber;
 
  Black.Blue = Black.Green = Black.Red = Black.Reserved = 0;
  White.Blue = White.Green = White.Red = White.Reserved = 0xFF;
 
  //
  // Register ENTER as CONTINUE key
  //
  Enter.ScanCode    = SCAN_NULL;
  Enter.UnicodeChar = CHAR_CARRIAGE_RETURN;
  EfiBootManagerRegisterContinueKeyOption (0, &amp;Enter, NULL);
  //
  // Map F2 to Boot Manager Menu
  //
  F2.ScanCode    = SCAN_F2;
  F2.UnicodeChar = CHAR_NULL;
  EfiBootManagerGetBootManagerMenu (&amp;BootOption);
  EfiBootManagerAddKeyOptionVariable (NULL, (UINT16) BootOption.OptionNumber, 0, &amp;F2, NULL);
 
  //
  // 3. Boot Device List menu
  //
  F7.ScanCode     = SCAN_F7;
  F7.UnicodeChar  = CHAR_NULL;
  OptionNumber    = GetBootManagerMenuAppOption ();
  EfiBootManagerAddKeyOptionVariable (NULL, (UINT16)OptionNumber, 0, &amp;F7, NULL);
 
  PrintXY (10, 10, &amp;White, &amp;Black, L"F2    to enter Setup.                              ");
  PrintXY (10, 30, &amp;White, &amp;Black, L"F7    to enter Boot Manager Menu.");
  PrintXY (10, 50, &amp;White, &amp;Black, L"Enter to boot directly.");
}

最终修改\OvmfPkg\Library\PlatformBootManagerLib\BdsPlatform.c 代码如下:

//LABZ_Start
EFI_GUID mBootMenuFile = {
  0xEEC25BDC, 0x67F2, 0x4D95, { 0xB1, 0xD5, 0xF8, 0x1B, 0x20, 0x39, 0xD1, 0x1D }
};
 
 
/**
  Check if it's a Device Path pointing to BootManagerMenuApp.
 
  @param  DevicePath     Input device path.
 
  @retval TRUE   The device path is BootManagerMenuApp File Device Path.
  @retval FALSE  The device path is NOT BootManagerMenuApp File Device Path.
**/
BOOLEAN
IsBootManagerMenuAppFilePath (
  EFI_DEVICE_PATH_PROTOCOL     *DevicePath
)
{
  EFI_HANDLE                      FvHandle;
  VOID                            *NameGuid;
  EFI_STATUS                      Status;
 
  Status = gBS->LocateDevicePath (&amp;gEfiFirmwareVolume2ProtocolGuid, &amp;DevicePath, &amp;FvHandle);
  if (!EFI_ERROR (Status)) {
    NameGuid = EfiGetNameGuidFromFwVolDevicePathNode ((CONST MEDIA_FW_VOL_FILEPATH_DEVICE_PATH *) DevicePath);
    if (NameGuid != NULL) {
      return CompareGuid (NameGuid, &amp;mBootMenuFile);
    }
  }
 
  return FALSE;
}
 
EFI_DEVICE_PATH *
FvFilePath (
  EFI_GUID                     *FileGuid
  )
{
 
  EFI_STATUS                         Status;
  EFI_LOADED_IMAGE_PROTOCOL          *LoadedImage;
  MEDIA_FW_VOL_FILEPATH_DEVICE_PATH  FileNode;
 
  EfiInitializeFwVolDevicepathNode (&amp;FileNode, FileGuid);
 
  Status = gBS->HandleProtocol (
                  gImageHandle,
                  &amp;gEfiLoadedImageProtocolGuid,
                  (VOID **) &amp;LoadedImage
                  );
  ASSERT_EFI_ERROR (Status);
  return AppendDevicePathNode (
           DevicePathFromHandle (LoadedImage->DeviceHandle),
           (EFI_DEVICE_PATH_PROTOCOL *) &amp;FileNode
           );
}
 
/**
  Create one boot option for BootManagerMenuApp.
 
  @param  FileGuid          Input file guid for the BootManagerMenuApp.
  @param  Description       Description of the BootManagerMenuApp boot option.
  @param  Position          Position of the new load option to put in the ****Order variable.
  @param  IsBootCategory    Whether this is a boot category.
 
 
  @retval OptionNumber      Return the option number info.
 
**/
UINTN
RegisterBootManagerMenuAppBootOption (
  EFI_GUID                         *FileGuid,
  CHAR16                           *Description,
  UINTN                            Position,
  BOOLEAN                          IsBootCategory
  )
{
  EFI_STATUS                       Status;
  EFI_BOOT_MANAGER_LOAD_OPTION     NewOption;
  EFI_DEVICE_PATH_PROTOCOL         *DevicePath;
  UINTN                            OptionNumber;
 
  DevicePath = FvFilePath (FileGuid);
  Status = EfiBootManagerInitializeLoadOption (
             &amp;NewOption,
             LoadOptionNumberUnassigned,
             LoadOptionTypeBoot,
             IsBootCategory ? LOAD_OPTION_ACTIVE : LOAD_OPTION_CATEGORY_APP,
             Description,
             DevicePath,
             NULL,
             0
             );
  ASSERT_EFI_ERROR (Status);
  FreePool (DevicePath);
 
  Status = EfiBootManagerAddLoadOptionVariable (&amp;NewOption, Position);
  ASSERT_EFI_ERROR (Status);
 
  OptionNumber = NewOption.OptionNumber;
 
  EfiBootManagerFreeLoadOption (&amp;NewOption);
 
  return OptionNumber;
}
/**
  Return the boot option number to the BootManagerMenuApp.
 
  If not found it in the current boot option, create a new one.
 
  @retval OptionNumber   Return the boot option number to the BootManagerMenuApp.
 
**/
UINTN
GetBootManagerMenuAppOption (
  VOID
  )
{
  UINTN                        BootOptionCount;
  EFI_BOOT_MANAGER_LOAD_OPTION *BootOptions;
  UINTN                        Index;
  UINTN                        OptionNumber;
 
  OptionNumber = 0;
 
  BootOptions = EfiBootManagerGetLoadOptions (&amp;BootOptionCount, LoadOptionTypeBoot);
 
  for (Index = 0; Index &lt; BootOptionCount; Index++) {
    if (IsBootManagerMenuAppFilePath (BootOptions[Index].FilePath)) {
      OptionNumber = BootOptions[Index].OptionNumber;
      break;
    }
  }
 
  EfiBootManagerFreeLoadOptions (BootOptions, BootOptionCount);
 
  if (Index >= BootOptionCount) {
    //
    // If not found the BootManagerMenuApp, create it.
    //
    OptionNumber = (UINT16) RegisterBootManagerMenuAppBootOption (&amp;mBootMenuFile, L"UEFI BootManagerMenuApp", (UINTN) -1, FALSE);
  }
 
  return OptionNumber;
}
//LABZ_End
VOID
PlatformRegisterOptionsAndKeys (
  VOID
  )
{
  EFI_STATUS                   Status;
  EFI_INPUT_KEY                Enter;
  EFI_INPUT_KEY                F2;
  EFI_INPUT_KEY                F7;  
  EFI_INPUT_KEY                Esc;
  EFI_BOOT_MANAGER_LOAD_OPTION BootOption;
  UINTN                        OptionNumber;
  //
  // Register ENTER as CONTINUE key
  //
  Enter.ScanCode    = SCAN_NULL;
  Enter.UnicodeChar = CHAR_CARRIAGE_RETURN;
  Status = EfiBootManagerRegisterContinueKeyOption (0, &amp;Enter, NULL);
  ASSERT_EFI_ERROR (Status);
 
  //
  // Map F2 to Boot Manager Menu
  //
  F2.ScanCode     = SCAN_F2;
  F2.UnicodeChar  = CHAR_NULL;
  Esc.ScanCode    = SCAN_ESC;
  Esc.UnicodeChar = CHAR_NULL;
  Status = EfiBootManagerGetBootManagerMenu (&amp;BootOption);
  ASSERT_EFI_ERROR (Status);
  Status = EfiBootManagerAddKeyOptionVariable (
             NULL, (UINT16) BootOption.OptionNumber, 0, &amp;F2, NULL
             );
  ASSERT (Status == EFI_SUCCESS || Status == EFI_ALREADY_STARTED);
  Status = EfiBootManagerAddKeyOptionVariable (
             NULL, (UINT16) BootOption.OptionNumber, 0, &amp;Esc, NULL
             );
  ASSERT (Status == EFI_SUCCESS || Status == EFI_ALREADY_STARTED);
   
  //LABZ_Start
  //
  // 3. Boot Device List menu
  //
  F7.ScanCode     = SCAN_F7;
  F7.UnicodeChar  = CHAR_NULL;
  OptionNumber    = GetBootManagerMenuAppOption ();
  EfiBootManagerAddKeyOptionVariable (NULL, (UINT16)OptionNumber, 0, &amp;F7, NULL);  
  //LABZ_End
}

此外，在 \OvmfPkg\OvmfPkgX64.dsc 中添加BootManagerMenuApp.inf如下：

    &lt;PcdsFixedAtBuild>
      gEfiMdePkgTokenSpaceGuid.PcdDebugPropertyMask|0xFF
      gEfiShellPkgTokenSpaceGuid.PcdShellLibAutoInitialize|FALSE
      gEfiMdePkgTokenSpaceGuid.PcdUefiLibMaxPrintBufferSize|8000
  }
 
  MdeModulePkg/Application/BootManagerMenuApp/BootManagerMenuApp.inf
 
!if $(SECURE_BOOT_ENABLE) == TRUE
  SecurityPkg/VariableAuthenticated/SecureBootConfigDxe/SecureBootConfigDxe.inf
  OvmfPkg/EnrollDefaultKeys/EnrollDefaultKeys.inf
!endif

\OvmfPkg\OvmfPkgX64.fdf修改如下：

!if $(TOOL_CHAIN_TAG) != "XCODE5"
INF  ShellPkg/DynamicCommand/TftpDynamicCommand/TftpDynamicCommand.inf
INF  ShellPkg/DynamicCommand/HttpDynamicCommand/HttpDynamicCommand.inf
INF  OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.inf
!endif
INF  ShellPkg/Application/Shell/Shell.inf
 
INF  MdeModulePkg/Application/BootManagerMenuApp/BootManagerMenuApp.inf
 
INF MdeModulePkg/Logo/LogoDxe.inf
 
#
# Network modules
#
!if $(E1000_ENABLE)

可以看到整体和之前的“BootMenu插入自己的Application”并无多大差别，只是多了使用EfiBootManagerAddKeyOptionVariable() 函数将 Application 和快捷键关联起来的。

运行结果：

NASM Assert 一个错误的方法

有时候为了确定代码是否编译到，我们需要在代码中添加让编译器报错的指令，对于 MASM 来说是 .ERR。在 NASM 中是”%error”【参考1】。编写例子如下：

segment code
.start:
mov ax,data
mov ds,ax
mov ax,stack
mov ss,ax
mov sp,stacktop
 
%error "assert error here" 
 
mov ax,0x0600
mov bh,0x43
xor cx,cx
mov dh,24
mov dl,79
int 0x10   
 
mov dx,hello
mov ah,9
int 0x21   
 
mov ax,0x4c00
int 0x21  
 
segment data
 
hello : db 'hello,world',13,10,'$'
 
segment stack stack
 
resb 64
 
stacktop:

编译时会自动报错如下：

此外，从我的实验来看，在　BIOS　代码中的　NASM 代码中随意插入字符并不能使得编译过程报错停止下来，所以如果有需要务必使用上述方法。

参考：

https://www.nasm.us/doc/nasmdoc4.html#section-4.9

4.9 Reporting User-Defined Errors: %error, %warning, %fatal

The preprocessor directive %error will cause NASM to report an error if it occurs in assembled code. So if other users are going to try to assemble your source files, you can ensure that they define the right macros by means of code like this:

%ifdef F1

; do some setup

%elifdef F2

; do some different setup

%else

%error “Neither F1 nor F2 was defined.”

%endif

Then any user who fails to understand the way your code is supposed to be assembled will be quickly warned of their mistake, rather than having to wait until the program crashes on being run and then not knowing what went wrong.

Similarly, %warning issues a warning, but allows assembly to continue:

%ifdef F1

; do some setup

%elifdef F2

; do some different setup

%else

%warning “Neither F1 nor F2 was defined, assuming F1.”

%define F1

%endif

%error and %warning are issued only on the final assembly pass. This makes them safe to use in conjunction with tests that depend on symbol values.

%fatal terminates assembly immediately, regardless of pass. This is useful when there is no point in continuing the assembly further, and doing so is likely just going to cause a spew of confusing error messages.

It is optional for the message string after %error, %warning or %fatal to be quoted. If it is not, then single-line macros are expanded in it, which can be used to display more information to the user. For example:

%if foo > 64

%assign foo_over foo-64

%error foo is foo_over bytes too large

%endif

Windows 全自动安装

之前介绍过的通过WinPE启动，通过软件将安装好的硬盘制作成镜像，然后当有需要时直接恢复的方法。但是更多时候我们出于测试的目的，需要安装最新版本的 Pure OS。这次介绍的全自动安装也就是无人值守模式安装，就是说只需要启动到安装盘上，Windows会自动完成包括分区格式化在内的全部工作。这是Windows自带的功能，只需要将特定的autounattend.xml 放置在启动盘的根目录下即可。具体做法如下：

1. 在 https://schneegans.de/windows/unattend-generator/ 根据需要生成 autounattend.xml 文件；

2.对于有要求配置 WIFI 的Windows可以在XML 文件中加入

&lt;OOBE>
&lt;HideWirelessSetupInOOBE>true&lt;/HideWirelessSetupInOOBE>
&lt;/OOBE>

3.将 autounattend.xml 文件放置在安装盘的根目录下，启动安装即可。

这里放一个我制作好的：

&lt;?xml version="1.0" encoding="utf-8"?>
&lt;unattend xmlns="urn:schemas-microsoft-com:unattend" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State">
  &lt;settings pass="offlineServicing" />
  &lt;settings pass="windowsPE">
    &lt;component name="Microsoft-Windows-International-Core-WinPE" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS">
      &lt;SetupUILanguage>
        &lt;UILanguage>en-US&lt;/UILanguage>
      &lt;/SetupUILanguage>
      &lt;InputLocale>0409:00000409&lt;/InputLocale>
      &lt;SystemLocale>en-US&lt;/SystemLocale>
      &lt;UILanguage>en-US&lt;/UILanguage>
      &lt;UserLocale>en-US&lt;/UserLocale>
    &lt;/component>
    &lt;component name="Microsoft-Windows-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS">
      &lt;DiskConfiguration>
        &lt;WillShowUI>OnError&lt;/WillShowUI>
        &lt;Disk wcm:action="add">
          &lt;CreatePartitions>
            &lt;!-- EFI system partition -->
            &lt;CreatePartition wcm:action="add">
              &lt;Order>1&lt;/Order>
              &lt;Type>EFI&lt;/Type>
              &lt;Size>100&lt;/Size>
            &lt;/CreatePartition>
            &lt;!-- Microsoft reserved partition (MSR) -->
            &lt;CreatePartition wcm:action="add">
              &lt;Order>2&lt;/Order>
              &lt;Type>MSR&lt;/Type>
              &lt;Size>16&lt;/Size>
            &lt;/CreatePartition>
            &lt;!-- Windows partition -->
            &lt;CreatePartition wcm:action="add">
              &lt;Order>3&lt;/Order>
              &lt;Type>Primary&lt;/Type>
              &lt;Extend>true&lt;/Extend>
            &lt;/CreatePartition>
          &lt;/CreatePartitions>
          &lt;ModifyPartitions>
            &lt;!-- EFI system partition -->
            &lt;ModifyPartition wcm:action="add">
              &lt;Order>1&lt;/Order>
              &lt;PartitionID>1&lt;/PartitionID>
              &lt;Label>System&lt;/Label>
              &lt;Format>FAT32&lt;/Format>
            &lt;/ModifyPartition>
            &lt;!-- Microsoft reserved partition (MSR) -->
            &lt;ModifyPartition wcm:action="add">
              &lt;Order>2&lt;/Order>
              &lt;PartitionID>2&lt;/PartitionID>
            &lt;/ModifyPartition>
            &lt;!-- Windows partition -->
            &lt;ModifyPartition wcm:action="add">
              &lt;Order>3&lt;/Order>
              &lt;PartitionID>3&lt;/PartitionID>
              &lt;Label>Windows&lt;/Label>
              &lt;Format>NTFS&lt;/Format>
              &lt;Letter>C&lt;/Letter>
            &lt;/ModifyPartition>
          &lt;/ModifyPartitions>
          &lt;DiskID>0&lt;/DiskID>
          &lt;WillWipeDisk>true&lt;/WillWipeDisk>
        &lt;/Disk>
      &lt;/DiskConfiguration>
      &lt;ImageInstall>
        &lt;OSImage>
          &lt;InstallTo>
            &lt;DiskID>0&lt;/DiskID>
            &lt;PartitionID>3&lt;/PartitionID>
          &lt;/InstallTo>
        &lt;/OSImage>
      &lt;/ImageInstall>
      &lt;UserData>
        &lt;ProductKey>
          &lt;Key>VK7JG-NPHTM-C97JM-9MPGT-3V66T&lt;/Key>
        &lt;/ProductKey>
        &lt;AcceptEula>true&lt;/AcceptEula>
      &lt;/UserData>
    &lt;/component>
  &lt;/settings>
  &lt;settings pass="generalize" />
  &lt;settings pass="specialize" />
  &lt;settings pass="auditSystem" />
  &lt;settings pass="auditUser" />
  &lt;settings pass="oobeSystem">
    &lt;component name="Microsoft-Windows-International-Core" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS">
      &lt;InputLocale>0409:00000409&lt;/InputLocale>
      &lt;SystemLocale>en-US&lt;/SystemLocale>
      &lt;UILanguage>en-US&lt;/UILanguage>
      &lt;UserLocale>en-US&lt;/UserLocale>
    &lt;/component>
    &lt;component name="Microsoft-Windows-Shell-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS">
      &lt;UserAccounts>
        &lt;AdministratorPassword>
          &lt;Value>password&lt;/Value>
          &lt;PlainText>true&lt;/PlainText>
        &lt;/AdministratorPassword>
      &lt;/UserAccounts>
      &lt;AutoLogon>
        &lt;Username>Administrator&lt;/Username>
        &lt;Enabled>true&lt;/Enabled>
        &lt;LogonCount>1&lt;/LogonCount>
        &lt;Password>
          &lt;Value>password&lt;/Value>
          &lt;PlainText>true&lt;/PlainText>
        &lt;/Password>
      &lt;/AutoLogon>
      &lt;OOBE>
        &lt;ProtectYourPC>3&lt;/ProtectYourPC>
        &lt;HideEULAPage>true&lt;/HideEULAPage>
        &lt;HideWirelessSetupInOOBE>true&lt;/HideWirelessSetupInOOBE>
      &lt;/OOBE>
    &lt;/component>
  &lt;/settings>
&lt;/unattend>

安装后对于有一些 Windows 会要求输入密码，对应的 Administrator 密码为 password

虚拟机中测试视频可以在B站看到，在VirtualBox上安装 22616.1.220502-1800

本文提到的 autounattend.xml 下载

autounattend 下载

ESP32 创建图片 WebServer

这次介绍一个比较好玩的：通过 ESP32 创建一个 WebServer ，通过浏览器访问的时候自动播放预先定义好的图片序列。

制作方法：

1.创建一个 640×480的图片，放上彩色文字，便于观察，保存为 JPG 格式

2.旋转文字，再保存成另外一个文件

3.重复上述动作我们能获得4个文件

4.使用 bin2c 工具将四个文件转化为4个C语言h文件

5.文件头定义中做一点调整，图片大小命名为 picN_size, 内容命名为 picN 这种

6.接下来就可以编写我们的代码了

#include "esp_camera.h"
#include &lt;WiFi.h>
#include "esp_timer.h"
#include "img_converters.h"
#include "Arduino.h"
#include "fb_gfx.h"
#include "soc/soc.h"
#include "soc/rtc_cntl_reg.h"
#include "esp_http_server.h"
#include "pic\ph0.h"
#include "pic\ph1.h"
#include "pic\ph2.h"
#include "pic\ph3.h"
 
// 这里改成你自己的 WIFI 名称和密码
const char* ssid = "YOUWIFI";
const char* password = "PASSWORD";
 
#define PART_BOUNDARY "123456789000000000000987654321"
 
static const char* _STREAM_CONTENT_TYPE = "multipart/x-mixed-replace;boundary=" PART_BOUNDARY;
static const char* _STREAM_BOUNDARY = "\r\n--" PART_BOUNDARY "\r\n";
static const char* _STREAM_PART = "Content-Type: image/jpeg\r\nContent-Length: %u\r\n\r\n";
 
httpd_handle_t stream_httpd = NULL;
 
static esp_err_t stream_handler(httpd_req_t *req) {
  esp_err_t res = ESP_OK;
  size_t _jpg_buf_len = 0;
  uint8_t * _jpg_buf = NULL;
  char * part_buf[64];
   
  static int index=0;
   
  res = httpd_resp_set_type(req, _STREAM_CONTENT_TYPE);
  if (res != ESP_OK) {
    return res;
  }
 
  while (true) {
    // 这里设定一个循环，轮流发送PIC0-4
    if (index==0) {
      _jpg_buf_len = pic0_size;
      _jpg_buf = (uint8_t *)pic0; 
    } else if (index==1) {
      _jpg_buf_len = pic1_size;
      _jpg_buf = (uint8_t *)pic1; 
    } else if (index==2) {
      _jpg_buf_len = pic2_size;
      _jpg_buf = (uint8_t *)pic2; 
    } else if (index==3) {
      _jpg_buf_len = pic3_size;
      _jpg_buf = (uint8_t *)pic3; 
    } 
    // 如果发送完PIC3 接来发送PIC0
    index=(index+1)%4;
 
    if (res == ESP_OK) {
      size_t hlen = snprintf((char *)part_buf, 64, _STREAM_PART, _jpg_buf_len);
      res = httpd_resp_send_chunk(req, (const char *)part_buf, hlen);
    }
    if (res == ESP_OK) {
      res = httpd_resp_send_chunk(req, (const char *)_jpg_buf, _jpg_buf_len);
    }
    if (res == ESP_OK) {
      res = httpd_resp_send_chunk(req, _STREAM_BOUNDARY, strlen(_STREAM_BOUNDARY));
    }
    if (res != ESP_OK) {
      break;
    }
    Serial.printf("MJPG: %uB\n",(uint32_t)(_jpg_buf_len));
  }
  return res;
}
 
void startPicServer() {
  httpd_config_t config = HTTPD_DEFAULT_CONFIG();
  config.server_port = 80;
 
  httpd_uri_t index_uri = {
    .uri       = "/",
    .method    = HTTP_GET,
    .handler   = stream_handler,
    .user_ctx  = NULL
  };
 
  if (httpd_start(&amp;stream_httpd, &amp;config) == ESP_OK) {
    httpd_register_uri_handler(stream_httpd, &amp;index_uri);
  }
}
 
void setup() {
  WRITE_PERI_REG(RTC_CNTL_BROWN_OUT_REG, 0); //disable brownout detector
 
  Serial.begin(115200);
  Serial.setDebugOutput(false);
 
  // Wi-Fi connection
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
 
  Serial.print("Camera Stream Ready! Go to: http://");
  Serial.print(WiFi.localIP());
 
  //启动
  startPicServer();
}
 
void loop() {
  delay(1);
}

7.运行之后串口监视器会输出当前 WebServer 的 IP ，将地址在浏览器中打开即可看到结果：

ESP32PICWebServer下载

Step to UEFI (260）Section Alignment(0x20) is not 4K

查看 Log 的过程中，发现在 DXE 阶段有错误报出，本文针对这个问题进行了一点研究。

首先，遇到的错误信息如下：

InstallProtocolInterface: BC62157E-3E33-4FEC-9920-2D3B36D750DF 7543E98
ProtectUefiImageCommon - 0x7543B40
  - 0x0000000007105000 - 0x0000000000005E60
InstallProtocolInterface: AA0E8BC1-DABC-46B0-A844-37B8169B2BEA 710A9C0
Loading driver 4B28E4C7-FF36-4E10-93CF-A82159E777C5
InstallProtocolInterface: 5B1B31A1-9562-11D2-8E3F-00A0C969723B 7543140
!!!!!!!!  InsertImageRecord - Section Alignment(0x20) is not 4K  !!!!!!!!
!!!!!!!!  Image - c:\buildbs\stable202108org\Build\OvmfX64\DEBUG_VS2015x86\X64\MdeModulePkg\Universal\ResetSystemRuntimeDxe\ResetSystemRuntimeDxe\DEBUG\ResetSystemRuntimeDxe.pdb  !!!!!!!!
Loading driver at 0x00007AE1000 EntryPoint=0x00007AE14D4 ResetSystemRuntimeDxe.efi
InstallProtocolInterface: BC62157E-3E33-4FEC-9920-2D3B36D750DF 7543418
ProtectUefiImageCommon - 0x7543140
  - 0x0000000007AE1000 - 0x00000000000041A0

接下来定位。输出错误的代码位于 \mdemodulepkg\core\dxe\misc\MemoryAttributesTable.c 中的InsertImageRecord() 函数中：

/**
  Insert image record.
 
  @param  RuntimeImage    Runtime image information
**/
VOID
InsertImageRecord (
  IN EFI_RUNTIME_IMAGE_ENTRY  *RuntimeImage
  )
……………
  //
  // Get SectionAlignment
  //
  if (Hdr.Pe32->OptionalHeader.Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
    SectionAlignment  = Hdr.Pe32->OptionalHeader.SectionAlignment;
  } else {
    SectionAlignment  = Hdr.Pe32Plus->OptionalHeader.SectionAlignment;
  }
  SetMemoryAttributesTableSectionAlignment (SectionAlignment);
  if ((SectionAlignment &amp; (RUNTIME_PAGE_ALLOCATION_GRANULARITY - 1)) != 0) {
    DEBUG ((DEBUG_WARN, "!!!!!!!!  InsertImageRecord - Section Alignment(0x%x) is not %dK  !!!!!!!!\n",
      SectionAlignment, RUNTIME_PAGE_ALLOCATION_GRANULARITY >> 10));
    PdbPointer = PeCoffLoaderGetPdbPointer ((VOID*) (UINTN) ImageAddress);
    if (PdbPointer != NULL) {
      DEBUG ((DEBUG_WARN, "!!!!!!!!  Image - %a  !!!!!!!!\n", PdbPointer));
    }
    goto Finish;
  }
…………

在\MdePkg\Include\X64\ProcessorBind.h 有如下定义：

///
/// Page allocation granularity for x64
///
#define DEFAULT_PAGE_ALLOCATION_GRANULARITY   (0x1000)
#define RUNTIME_PAGE_ALLOCATION_GRANULARITY   (0x1000)

可以看到，SectionAlignment 来自 Hdr.Pe32Plus->OptionalHeader.SectionAlignment，使用 CFF 查看 ResetSystemRuntimeDxe.efi 这个文件，注意下图中的2个位置。上述代码首先检查ImageType（Subsystem）是否为EFI_IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER，如果是再继续检查SectionAlignment是否为4K，如果不是 4K 对齐那么就进行报错。

ImageType的定义在\MdeModulePkg\Universal\ResetSystemRuntimeDxe\ResetSystemRuntimeDxe.inf 文件中：

[Defines]
  INF_VERSION                    = 0x00010005
  BASE_NAME                      = ResetSystemRuntimeDxe
  MODULE_UNI_FILE                = ResetSystemRuntimeDxe.uni
  FILE_GUID                      = 4B28E4C7-FF36-4e10-93CF-A82159E777C5
  MODULE_TYPE                    = DXE_RUNTIME_DRIVER
  VERSION_STRING                 = 1.0
 
  ENTRY_POINT                    = InitializeResetSystem

搜索所有 MODULE_TYPE 为 DXE_RUNTIME_DRIVER 的 Module 发现在运行期都有这样的问题。

确定了问题，找到了问题点，接下来就开始分析“为什么出现不满足条件”。

检查\Build\OvmfX64\DEBUG_VS2015x86\X64\MdeModulePkg\Universal\ResetSystemRuntimeDxe\ResetSystemRuntimeDxe\Makefile 文件有下面一行：

DLINK_FLAGS = /NOLOGO /NODEFAULTLIB /IGNORE:4001 /OPT:REF /OPT:ICF=10 /MAP /ALIGN:32 /SECTION:.xdata,D /SECTION:.pdata,D /Machine:X64 /LTCG /DLL /ENTRY:$(IMAGE_ENTRY_POINT) /SUBSYSTEM:EFI_BOOT_SERVICE_DRIVER /SAFESEH:NO /BASE:0 /DRIVER /DEBUG
（注意 /ALIGN:32 参数）

尝试修改上面为 /ALIGN:0x1000 修改之后再次编译（需要同样的环境，进入 Debug 目录直接运行 NMAKE，这种方法在之前的实验中有介绍过），生成的EFI如下：

我们需要修改EFI 的生成方式。在\Conf\tools_def.txt 可以看到默认的编译参数：

 DEBUG_VS2015x86_X64_DLINK_FLAGS  = /NOLOGO /NODEFAULTLIB /IGNORE:4001 /OPT:REF /OPT:ICF=10 /MAP /ALIGN:32 /SECTION:.xdata,D /SECTION:.pdata,D /Machine:X64 /LTCG /DLL /ENTRY:$(IMAGE_ENTRY_POINT) /SUBSYSTEM:EFI_BOOT_SERVICE_DRIVER /SAFESEH:NO /BASE:0 /DRIVER /DEBUG
RELEASE_VS2015x86_X64_DLINK_FLAGS  = /NOLOGO /NODEFAULTLIB /IGNORE:4001 /IGNORE:4254 /OPT:REF /OPT:ICF=10 /MAP /ALIGN:32 /SECTION:.xdata,D /SECTION:.pdata,D /Machine:X64 /LTCG /DLL /ENTRY:$(IMAGE_ENTRY_POINT) /SUBSYSTEM:EFI_BOOT_SERVICE_DRIVER /SAFESEH:NO /BASE:0 /DRIVER /MERGE:.rdata=.data
NOOPT_VS2015x86_X64_DLINK_FLAGS    = /NOLOGO /NODEFAULTLIB /IGNORE:4001 /OPT:REF /OPT:ICF=10 /MAP /ALIGN:32 /SECTION:.xdata,D /SECTION:.pdata,D /Machine:X64 /LTCG /DLL /ENTRY:$(IMAGE_ENTRY_POINT) /SUBSYSTEM:EFI_BOOT_SERVICE_DRIVER /SAFESEH:NO /BASE:0 /DRIVER /DEBUG

这里我们使用的是DEBUG版，所以需要修改为下面这样(/ALIGN:0x1000)

DEBUG_VS2015x86_X64_DLINK_FLAGS = /NOLOGO /NODEFAULTLIB /IGNORE:4001 /OPT:REF /OPT:ICF=10 /MAP /ALIGN:0x1000 /SECTION:.xdata,D /SECTION:.pdata,D /Machine:X64 /LTCG /DLL /ENTRY:$(IMAGE_ENTRY_POINT) /SUBSYSTEM:EFI_BOOT_SERVICE_DRIVER /SAFESEH:NO /BASE:0 /DRIVER /DEBUG

修改之后重新编译OVMF,得到的ResetSystemRuntimeDxe.efi 和前面手工修改的结果相同。但是这样修改会导致编译最后一步无法通过：

Generating FVMAIN_COMPACT FV
Generating PEIFV FV
##### ['GenFv', '-a', 'c:\\buildbs\\stable202108org\\Build\\OvmfX64\\DEBUG_VS2015x86\\FV\\Ffs\\PEIFV.inf', '-o', 'c:\\buildbs\\stable202108org\\Build\\OvmfX64\\DEBUG_VS2015x86\\FV\\PEIFV.Fv', '-i', 'c:\\buildbs\\stable202108org\\Build\\OvmfX64\\DEBUG_VS2015x86\\FV\\PEIFV.inf']
Return Value = 2
GenFv: ERROR 3000: Invalid
  PE image Section-Alignment and File-Alignment do not match : c:\buildbs\stable202108org\Build\OvmfX64\DEBUG_VS2015x86\FV\Ffs\52C05B14-0B98-496c-BC3B-04B50211D680PeiCore\52C05B14-0B98-496c-BC3B-04B50211D680.ffs.
GenFv: ERROR 3000: Invalid
  Could not rebase c:\buildbs\stable202108org\Build\OvmfX64\DEBUG_VS2015x86\FV\Ffs\52C05B14-0B98-496c-BC3B-04B50211D680PeiCore\52C05B14-0B98-496c-BC3B-04B50211D680.ffs.
 
build.py...
 : error 7000: Failed to generate FV
build.py...
 : error 7000: Failed to execute command

看起来是因为 PE头中　SectionAlignment和FileAlignment 不同导致的，在【参考1】介绍了一个设置 FileAlignment 的参数。同样的，将这个参数加入到 tools_def.txt 文件中：

  DEBUG_VS2015x86_X64_DLINK_FLAGS  = /NOLOGO /NODEFAULTLIB /IGNORE:4001 /OPT:REF /OPT:ICF=10 /MAP /ALIGN:0x1000 /FILEALIGN:0x1000 /SECTION:.xdata,D /SECTION:.pdata,D /Machine:X64 /LTCG /DLL /ENTRY:$(IMAGE_ENTRY_POINT) /SUBSYSTEM:EFI_BOOT_SERVICE_DRIVER /SAFESEH:NO /BASE:0 /DRIVER /DEBUG
（注意  /FILEALIGN:0x1000 ）

再次编译可以得到OVMF.FD ，使用QEMU 运行，Log 中就没有这个错误了。

这样的修改虽然能够解决问题，但是我们并不了解 InsertImageRecord() 函数的用途，后面有机会再继续进行分析。

参考：

1.https://blog.csdn.net/bagboy_taobao_com/article/details/7295575/

Step to UEFI (261）BootMenu插入自己的Application

在QEMU 的Boot Manager/Menu 中可以看到”EFI Internal Shell” 这个选项，选中之后会跳转到其中执行 Shell.efi，这次就尝试编代码在其中插入能够启动到自己Application的选项。

首先我们研究一下这个选项是如何插入的。在\ovmfpkg\library\platformbootmanagerlib\BdsPlatform.c 的 PlatformBootManagerAfterConsole()函数中有：

//
// Perform some platform specific connect sequence
//
PlatformBdsConnectSequence ();
 
EfiBootManagerRefreshAllBootOption ();
 
//
// Register UEFI Shell
//
PlatformRegisterFvBootOption (
  &amp;gUefiShellFileGuid, L"EFI Internal Shell", LOAD_OPTION_ACTIVE
  );
 
RemoveStaleFvFileOptions ();
SetBootOrderFromQemu ();

其中gUefiShellFileGuid 的定义在 \ShellPkg\ShellPkg.dec

# FILE_GUID as defined in ShellPkg/Application/Shell/Shell.inf
gUefiShellFileGuid              = {0x7c04a583, 0x9e3e, 0x4f1c, {0xad, 0x65, 0xe0, 0x52, 0x68, 0xd0, 0xb4, 0xd1}

也可以在\ShellPkg\Application\Shell\Shell.inf 中看到

[Defines]
  INF_VERSION                    = 0x00010006
  BASE_NAME                      = Shell
  FILE_GUID                      = 7C04A583-9E3E-4f1c-AD65-E05268D0B4D1 # gUefiShellFileGuid
  MODULE_TYPE                    = UEFI_APPLICATION
  VERSION_STRING                 = 1.0
  ENTRY_POINT                    = UefiMain

使用工具可以看到：

接下来我们着手设计一个自己的 Application 用于验证，需要特别注意的是，这个程序不能使用 SHELL 的任何Protocol和Service，因为调用它的时候没有 Shell。代码非常简单：

1. BootTest.c 如下

#include  &lt;Uefi.h>
EFI_STATUS
EFIAPI
UefiMain (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
        for (int i=0;i&lt;1000;i++) {
                SystemTable->ConOut->OutputString(
                        SystemTable->ConOut,
                        L"www.lab-z.com\n");
        }
 
   
  return(0);
}

2. BootTest.inf如下：

[Defines]
  INF_VERSION                    = 0x00010006
  BASE_NAME                      = BootTest
  FILE_GUID                      = a912f198-7f0e-4803-b908-b757b806ec89
  MODULE_TYPE                    = UEFI_APPLICATION
  VERSION_STRING                 = 0.1
  ENTRY_POINT                    = UefiMain
 
#
#  VALID_ARCHITECTURES           = IA32 X64 IPF
#
 
[Sources]
  BootTest.c
 
[Packages]
  MdePkg/MdePkg.dec
  ShellPkg/ShellPkg.dec
 
[LibraryClasses]
  UefiLib
  UefiApplicationEntryPoint
  DebugLib

EDK2 202108 已经没有 AppPkg ，所以我们直接放在 ShellPkg 中。接下来修改代码如下：

1.\OvmfPkg\OvmfPkgX64.dsc 中，插入 INF 文件

    &lt;PcdsFixedAtBuild>
      gEfiMdePkgTokenSpaceGuid.PcdDebugPropertyMask|0xFF
      gEfiShellPkgTokenSpaceGuid.PcdShellLibAutoInitialize|FALSE
      gEfiMdePkgTokenSpaceGuid.PcdUefiLibMaxPrintBufferSize|8000
  }
 
  ShellPkg/Application/BootTest/BootTest.inf
 
!if $(SECURE_BOOT_ENABLE) == TRUE
  SecurityPkg/VariableAuthenticated/SecureBootConfigDxe/SecureBootConfigDxe.inf
  OvmfPkg/EnrollDefaultKeys/EnrollDefaultKeys.inf
!endif

2.\OvmfPkg\OvmfPkgX64.fdf 中插入

!if $(TOOL_CHAIN_TAG) != "XCODE5"
INF  ShellPkg/DynamicCommand/TftpDynamicCommand/TftpDynamicCommand.inf
INF  ShellPkg/DynamicCommand/HttpDynamicCommand/HttpDynamicCommand.inf
INF  OvmfPkg/LinuxInitrdDynamicShellCommand/LinuxInitrdDynamicShellCommand.inf
!endif
INF  ShellPkg/Application/Shell/Shell.inf
INF  ShellPkg/Application/BootTest/BootTest.inf
 
INF MdeModulePkg/Logo/LogoDxe.inf
 
#
# Network modules
#
!if $(E1000_ENABLE)
  FILE DRIVER = 5D695E11-9B3F-4b83-B25F-4A8D5D69BE07 {
    SECTION PE32 = Intel3.5/EFIX64/E3522X2.EFI
  }

3. \OvmfPkg\Library\PlatformBootManagerLib\BdsPlatform.c 文件做插入 BootMenu的动作

定义一个 GUID，来自 BootTest.inf 中的FILE_GUID

EFI_GUID  gBootTest = {
    0xa912f198, 0x7f0e, 0x4803,
    { 0xb9, 0x08, 0xb7, 0x57, 0xb8, 0x06, 0xec, 0x89 } };

插入动作：

//
// Perform some platform specific connect sequence
//
PlatformBdsConnectSequence ();
 
EfiBootManagerRefreshAllBootOption ();
DEBUG((DEBUG_INFO, "LABZTest_Start\n"));
//
// Register a Test Application
//
PlatformRegisterFvBootOption(
    &amp;gBootTest, L"LABZTest", LOAD_OPTION_ACTIVE
);
DEBUG((DEBUG_INFO, "LABZTest_End\n"));
//
// Register UEFI Shell
//
PlatformRegisterFvBootOption (
  &amp;gUefiShellFileGuid, L"EFI Internal Shell", LOAD_OPTION_ACTIVE
  );

重新编译之后，可以用工具看到我们插入的 Application:

运行结果：

可以看到 BootMenu 中出现了我们设定的启动选项。

本文提到的用于测试的 BootTest:

BootTest 下载

ESP32 Time Error

最近在编译一个 ESP32 Arduino代码的时候碰到了如下很奇怪的问题：

In file included from c:\users\DaveX\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\gcc8_4_0-esp-2021r2-patch3\xtensa-esp32-elf\include\c++\8.4.0\bits\locale_facets_nonio.h:39,
                 from c:\users\DaveX\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\gcc8_4_0-esp-2021r2-patch3\xtensa-esp32-elf\include\c++\8.4.0\locale:41,
                 from c:\users\DaveX\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\gcc8_4_0-esp-2021r2-patch3\xtensa-esp32-elf\include\c++\8.4.0\iomanip:43,
                 from C:\Users\DaveX\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.4\libraries\BluetoothSerial\src\BTAddress.cpp:15:
c:\users\DaveX\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\gcc8_4_0-esp-2021r2-patch3\xtensa-esp32-elf\include\c++\8.4.0\ctime:64:11: error: '::clock' has not been declared
   using ::clock;
           ^~~~~
c:\users\DaveX\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\gcc8_4_0-esp-2021r2-patch3\xtensa-esp32-elf\include\c++\8.4.0\ctime:65:11: error: '::difftime' has not been declared
   using ::difftime;
           ^~~~~~~~
c:\users\DaveX\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\gcc8_4_0-esp-2021r2-patch3\xtensa-esp32-elf\include\c++\8.4.0\ctime:66:11: error: '::mktime' has not been declared
   using ::mktime;
           ^~~~~~
c:\users\DaveX\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\gcc8_4_0-esp-2021r2-patch3\xtensa-esp32-elf\include\c++\8.4.0\ctime:67:11: error: '::time' has not been declared
   using ::time;
           ^~~~
c:\users\DaveX\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\gcc8_4_0-esp-2021r2-patch3\xtensa-esp32-elf\include\c++\8.4.0\ctime:68:11: error: '::asctime' has not been declared
   using ::asctime;
           ^~~~~~~
c:\users\DaveX\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\gcc8_4_0-esp-2021r2-patch3\xtensa-esp32-elf\include\c++\8.4.0\ctime:69:11: error: '::ctime' has not been declared
   using ::ctime;
           ^~~~~
c:\users\DaveX\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\gcc8_4_0-esp-2021r2-patch3\xtensa-esp32-elf\include\c++\8.4.0\ctime:70:11: error: '::gmtime' has not been declared
   using ::gmtime;
           ^~~~~~
c:\users\DaveX\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\gcc8_4_0-esp-2021r2-patch3\xtensa-esp32-elf\include\c++\8.4.0\ctime:71:11: error: '::localtime' has not been declared
   using ::localtime;
           ^~~~~~~~~
c:\users\DaveX\appdata\local\arduino15\packages\esp32\tools\xtensa-esp32-elf-gcc\gcc8_4_0-esp-2021r2-patch3\xtensa-esp32-elf\include\c++\8.4.0\ctime:72:11: error: '::strftime' has not been declared
   using ::strftime;
           ^~~~~~~~

经过搜索，有人碰到了类似的问题，产生问题的原因是：使用的代码中有 time.h 这个名称的文件。我的代码中没有，但是使用到的 DFRobot_OLED12864 这个库里面有。解决方法很简单：把这个库中的time.h 改个名称即可。

希望能帮助到碰到同样问题的朋友。