| EDK II Standard Libraries | |
| ReadMe | |
| Beta Release | |
| 4:03 PM 8/2/2011 | |
| OVERVIEW | |
| ======== | |
| This document describes the EDK II specific aspects of installing, building, and | |
| using the Standard C Library component of the EDK II Application Development | |
| Kit, EADK. | |
| The EADK is comprised of three packages: AppPkg, StdLib, and StdLibPrivateInternalFiles. | |
| AppPkg This package contains applications which demonstrate use of the | |
| Standard C Library. | |
| These applications reside in AppPkg/Applications. | |
| Enquire This is a program that determines many properties of the | |
| C compiler and the target machine that Enquire is run on. The | |
| only changes required to port this 1990s era Unix program to | |
| EDK II were the addition of eight pragmas to enquire.c in | |
| order to disable some Microsoft VC++ specific warnings. | |
| Hello This is a very simple EDK II native application that doesn't use | |
| any features of the Standard C Library. | |
| Main This application is functionally identical to Hello, except that | |
| it uses the Standard C Library to provide a main() entry point. | |
| Python A port of the Python-2.7.1 interpreter for UEFI. This | |
| application is disabled by default. Un-comment the line for | |
| PythonCore.inf in the [Components] section of AppPkg.dsc to | |
| enable building Python. | |
| Sockets A collection of applications demonstrating use of the | |
| EDK II Socket Libraries. These applications include: | |
| * DataSink | |
| * DataSource | |
| * GetHostByAddr | |
| * GetHostByDns | |
| * GetHostByName | |
| * GetNetByAddr | |
| * GetNetByName | |
| * GetServByName | |
| * GetServByPort | |
| * RecvDgram | |
| * SetHostName | |
| * SetSockOpt | |
| * TftpServer | |
| * WebServer | |
| StdLib The StdLib package contains the standard header files as well as | |
| implementations of the standard libraries. | |
| StdLibPrivateInternalFiles The contents of this package are for the | |
| exclusive use of the library implementations in StdLib. Please do | |
| not use anything from this package in your application or else | |
| unexpected behavior may occur. | |
| This package may be removed in a future release. | |
| RELEASE NOTES | |
| ============= | |
| This release of the EADK has some restrictions, as described below. | |
| 1. Only the Microsoft VS2005 and VS2008, Intel C Compiler 10.1 (or later), | |
| GCC 4.3 (mingw32), GCC 4.4, and GCC 4.5 C compilers are supported for | |
| Ia32 or X64 CPU architectures. | |
| 2. The target machine must be running firmware which provides the | |
| UEFI 2.3 HII protocol. | |
| 3. The EADK has not been through Intel's Quality Assurance process. This | |
| means that specified standards compliance has not been validated, nor | |
| has it undergone formal functionality testing. | |
| 4. Applications must be launched from within the EFI Shell. | |
| 5. All file paths must use the forward slash, '/', as the separator | |
| character. | |
| 6. Absolute file paths may optionally be prefixed by a volume specifier | |
| such as "FS0:". The volume specifier is separated from the remainder | |
| of the path by a single colon ':'. The volume specifier must be one of | |
| the Shell's mapped volume names as shown by the "map" command. | |
| 7. Absolute file paths that don't begin with a volume specifier; | |
| e.g. paths that begin with "/", are relative to the currently selected | |
| volume. When the EFI Shell starts, there is NO selected volume. | |
| 8. The tmpfile(), and related, functions require that the current volume | |
| have a temporary directory as specified in <paths.h>. This directory | |
| is specified by macro _PATH_TMP. | |
| The Standard C Library provided by this package is a "hosted" implementation | |
| conforming to the ISO/IEC 9899-1990 C Language Standard with Addendum 1. This | |
| is commonly referred to as the "C 95" specification or ISO/IEC 9899:199409. | |
| The following instructions assume that you have an existing EDK II or UDK 2010 | |
| source tree that has been configured to build with your tool chain. For | |
| convenience, it is assumed that your EDK II source tree is located at | |
| C:\Source\Edk2. | |
| INSTALLATION | |
| ============ | |
| The EADK is integrated within the EDK II source tree and is included with | |
| current EDK II check-outs. If they are missing from your tree, they may be | |
| installed by extracting, downloading or copying them to the root of your EDK II | |
| source tree. The three package directories should be peers to the Conf, | |
| MdePkg, Nt32Pkg, etc. directories. | |
| The Python 2.7.1 distribution must be downloaded from python.org before the | |
| Python application can be built. Extracting Python-2.7.1.tgz into the | |
| AppPkg\Applications\Python directory will produce a Python-2.7.1 directory | |
| containing the Python distribution. Python files that had to be modified for | |
| EDK II are in the AppPkg\Applications\Python\PyMod-2.7.1 directory. These | |
| files need to be copied into the corresponding directories within Python-2.7.1. | |
| There are some boiler-plate declarations and definitions that need to be | |
| included in your application's INF and DSC build files. These are described | |
| in the CONFIGURATION section, below. | |
| BUILDING | |
| ======== | |
| It is not necessary to build the libraries separately from the target | |
| application(s). If the application references the libraries, as described in | |
| USAGE, below; the required libraries will be built as needed. | |
| To build the applications included in AppPkg, one would execute the following | |
| commands within the "Visual Studio Command Prompt" window: | |
| > cd C:\Source\Edk2 | |
| > .\edksetup.bat | |
| > build ?a X64 ?p AppPkg\AppPkg.dsc | |
| This will produce the application executables: Enquire.efi, Hello.efi, and | |
| Main.efi in the C:\Source\Edk2\Build\AppPkg\DEBUG_VS2008\X64 directory; with | |
| the DEBUG_VS2008 component being replaced with the actual tool chain and build | |
| type you have selected in Conf\Tools_def.txt. These executables can now be | |
| loaded onto the target platform and executed. | |
| If you examine the AppPkg.dsc file, you will notice that the StdLib package is | |
| referenced in order to resolve the library classes comprising the Standard | |
| C Library. This, plus referencing the StdLib package in your application's | |
| .inf file is all that is needed to link your application to the standard | |
| libraries. | |
| USAGE | |
| ===== | |
| This implementation of the Standard C Library is comprised of 16 separate | |
| libraries in addition to the standard header files. Nine of the libraries are | |
| associated with use of one of the standard headers; thus, if the header is used | |
| in an application, it must be linked with the associated library. Three | |
| libraries are used to provide the Console and File-system device abstractions. | |
| The libraries and associated header files are described in the following table. | |
| Library | |
| Class Header File(s) Notes | |
| ---------- ---------------- ------------------------------------------------- | |
| LibC -- Use Always -- This library is always required. | |
| LibCtype ctype.h, wctype.h Character classification and mapping | |
| LibLocale locale.h Localization types, macros, and functions | |
| LibMath math.h Mathematical functions, types, and macros | |
| LibStdio stdio.h Standard Input and Output functions, types, and | |
| macros | |
| LibStdLib stdlib.h General Utilities for numeric conversion, random | |
| num., etc. | |
| LibString string.h String copying, concatenation, comparison, | |
| & search | |
| LibSignal signal.h Functions and types for handling run-time | |
| conditions | |
| LibTime time.h Time and Date types, macros, and functions | |
| LibUefi sys/EfiSysCall.h Provides the UEFI system interface and | |
| "System Calls" | |
| LibWchar wchar.h Extended multibyte and wide character utilities | |
| LibNetUtil Network address and number manipulation utilities | |
| DevConsole Automatically provided File I/O abstractions for | |
| the UEFI Console device. No need to list this | |
| library class in your INF file(s). | |
| DevShell Add if desired File I/O abstractions using UEFI shell | |
| facilities. Add this to the application's main | |
| INF file if file-system access needed. | |
| DevUtility -- Do Not Use -- Utility functions used by the Device abstractions | |
| LibGdtoa -- Do Not Use -- This library is used internally and should not | |
| need to be explicitly specified by an | |
| application. It must be defined as one of the | |
| available library classes in the application's | |
| DSC file. | |
| Table 1: Standard Libraries | |
| ============================ | |
| These libraries must be fully described in the [LibraryClasses] section of the | |
| application package's DSC file. Then, each individual application needs to | |
| specify which libraries to link to by specifying the Library Class, from the | |
| above table, in the [LibraryClasses] section of the application's INF file. The | |
| AppPkg.dsc, StdLib.dsc, and Enquire.inf files provide good examples of this. | |
| More details are in the CONFIGURATION section, below. | |
| Within the source files of the application, use of the Standard headers and | |
| library functions follow standard C programming practices as formalized by | |
| ISO/IEC 9899:1990, with Addendum 1, (C 95) C language specification. | |
| CONFIGURATION | |
| ============= | |
| DSC Files | |
| --------- | |
| All EDK II packages which build applications that use the standard libraries | |
| must include some "boilerplate" text in the package's .dsc file. To make it | |
| easier, and to reduce cut-and-paste errors, the "boilerplate" text has been | |
| consolidated into a single file, StdLib/StdLib.inc, which can be included in | |
| your .dsc file using the !include directive. The provided AppPkg.dsc and | |
| StdLib.dsc files do this on their last line. | |
| Each affected section of the DSC file is described below. | |
| [LibraryClasses] | |
| # | |
| # Common Libraries | |
| # | |
| BaseLib|MdePkg/Library/BaseLib/BaseLib.inf | |
| BaseMemoryLib|MdePkg/Library/BaseMemoryLib/BaseMemoryLib.inf | |
| TimerLib|PerformancePkg/Library/DxeTscTimerLib/DxeTscTimerLib.inf | |
| # To run in an emulation environment, such as NT32, comment out | |
| # the TimerLib description above and un-comment the line below. | |
| # TimerLib| MdePkg/Library/BaseTimerLibNullTemplate/BaseTimerLibNullTemplate.inf | |
| # | |
| # C Standard Libraries | |
| # | |
| LibC|StdLib/LibC/LibC.inf | |
| LibStdLib|StdLib/LibC/StdLib/StdLib.inf | |
| LibString|StdLib/LibC/String/String.inf | |
| LibWchar|StdLib/LibC/Wchar/Wchar.inf | |
| LibCType|StdLib/LibC/Ctype/Ctype.inf | |
| LibTime|StdLib/LibC/Time/Time.inf | |
| LibStdio|StdLib/LibC/Stdio/Stdio.inf | |
| LibGdtoa|StdLib/LibC/gdtoa/gdtoa.inf | |
| LibLocale|StdLib/LibC/Locale/Locale.inf | |
| LibUefi|StdLib/LibC/Uefi/Uefi.inf | |
| LibMath|StdLib/LibC/Math/Math.inf | |
| LibSignal|StdLib/LibC/Signal/Signal.inf | |
| LibNetUtil|StdLib/LibC/LibGcc/LibGcc.inf | |
| # Libraries for device abstractions within the Standard C Library. | |
| # Applications should not directly access any functions defined | |
| # in these libraries. | |
| DevUtility|StdLib/LibC/Uefi/Devices/daUtility.inf | |
| DevConsole|StdLib/LibC/Uefi/Devices/daConsole.inf | |
| DevShell|StdLib/LibC/Uefi/Devices/daShell.inf | |
| Figure 1: Library Class Descriptions | |
| ==================================== | |
| Descriptions of the Library Classes comprising the Standard Libraries must be | |
| included in your application package's DSC file, as shown in Figure 1: Library | |
| Class Descriptions, above. | |
| The directives in Figure 2: Package Component Descriptions will create | |
| instances of the BaseLib and BaseMemoryLib library classes that are built | |
| with Link-time-Code-Generation disabled. This is necessary when using the | |
| Microsoft tool chains in order to allow the library's functions to be | |
| resolved during the second pass of the linker during Link-Time-Code-Generation | |
| of the application. | |
| [Components] | |
| # BaseLib and BaseMemoryLib need to be built with the /GL- switch | |
| # when using the Microsoft tool chains. This is required so that | |
| # the library functions can be resolved during the second pass of | |
| # the linker during link-time-code-generation. | |
| # | |
| MdePkg/Library/BaseLib/BaseLib.inf { | |
| <BuildOptions> | |
| MSFT:*_*_*_CC_FLAGS = /X /Zc:wchar_t /GL- | |
| } | |
| MdePkg/Library/BaseMemoryLib/BaseMemoryLib.inf { | |
| <BuildOptions> | |
| MSFT:*_*_*_CC_FLAGS = /X /Zc:wchar_t /GL- | |
| } | |
| Figure 2: Package Component Descriptions | |
| ======================================== | |
| The NULL TimerLib instance must be selected if you desire to run your | |
| application under an emulation environment -- unless there is a supported | |
| TimerLib for that environment. For example, the InOsEmuPkg provides a | |
| DxeTimerLib which can be used for the TimerLib instance. | |
| The "boilerplate" text in StdLib.inc will automatically adjust which Timer | |
| Library is instantiated based upon whether the $(EMULATE) macro has been | |
| defined, or not. | |
| ### | |
| # Select the correct TimerLib instance depending upon whether running under | |
| # an emulation environment, or not. | |
| !ifndef $(EMULATE) | |
| # Not running in an Emulation Environment | |
| [LibraryClasses.IA32.UEFI_APPLICATION] | |
| TimerLib|PerformancePkg/Library/DxeTscTimerLib/DxeTscTimerLib.inf | |
| [LibraryClasses.X64.UEFI_APPLICATION] | |
| TimerLib|PerformancePkg/Library/DxeTscTimerLib/DxeTscTimerLib.inf | |
| [LibraryClasses.IPF.UEFI_APPLICATION] | |
| PalLib|MdePkg/Library/UefiPalLib/UefiPalLib.inf | |
| TimerLib|MdePkg/Library/SecPeiDxeTimerLibCpu/SecPeiDxeTimerLibCpu.inf | |
| !else | |
| # Use this instance if Running in an Emulation Environment. | |
| [LibraryClasses.Common.UEFI_APPLICATION] | |
| TimerLib|MdePkg/Library/BaseTimerLibNullTemplate/BaseTimerLibNullTemplate.inf | |
| !endif | |
| Figure 3: Timer Library Selection | |
| ================================= | |
| Each compiler assumes, by default, that it will be used with standard libraries | |
| and headers provided by the compiler vendor. Many of these assumptions are | |
| incorrect for the UEFI environment. By including a BuildOptions section, as | |
| shown in Figure 3: Package Build Options, these assumptions can be | |
| tailored for compatibility with UEFI and the EDK II Standard Libraries. | |
| [BuildOptions] | |
| INTEL:*_*_IA32_CC_FLAGS = /Qfreestanding | |
| MSFT:*_*_IA32_CC_FLAGS = /X /Zc:wchar_t | |
| GCC:*_*_IA32_CC_FLAGS = /ffreestanding ?nostdinc ?nostdlib | |
| # The Build Options, below, are only used when building the C library | |
| # to be run under an emulation environment. The clock() system call | |
| # is modified to return -1 indicating that it is unsupported. | |
| # Just un-comment the lines below and select the correct | |
| # TimerLib instance, above. | |
| # INTEL:*_*_IA32_CC_FLAGS = /D NT32dvm | |
| # MSFT:*_*_IA32_CC_FLAGS = /D NT32dvm | |
| # GCC:*_*_IA32_CC_FLAGS = -DNT32dvm | |
| Figure 4: Package Build Options | |
| =============================== | |
| The "boilerplate" text can be included using a !include directive in the | |
| package's .dsc file. The provided AppPkg.dsc and StdLib.dsc files include | |
| the "boilerplate" text as follows: | |
| # Include Boilerplate text required for building with the Standard Libraries. | |
| # | |
| ############################################################################# | |
| !include StdLib/StdLib.inc | |
| Figure 5: "Boilerplate" Inclusion | |
| ================================= | |
| INF Files | |
| ========= | |
| The INF files for most modules will not require special directives in order to | |
| support the Standard Libraries. The two cases which could occur are described | |
| below. | |
| [LibraryClasses] | |
| UefiLib | |
| LibC | |
| LibString | |
| LibStdio | |
| DevShell | |
| Figure 6: Module Library Classes | |
| ================================ | |
| Modules of type UEFI_APPLICATION that perform file I/O should include library | |
| class DevShell. Including this library class will allow file operations to be | |
| handled by the UEFI Shell. Without this class, only Console I/O is permitted. | |
| [BuildOptions] | |
| INTEL:*_*_*_CC_FLAGS = /Qdiag-disable:181,186 | |
| MSFT:*_*_*_CC_FLAGS = /Oi- /wd4018 /wd4131 | |
| GCC:*_*_IPF_SYMRENAME_FLAGS = --redefine-syms=Rename.txt | |
| Figure 7: Module Build Options | |
| ============================== | |
| An application's INF file may need to include a [BuildOptions] section | |
| specifying additional compiler and linker flags necessary to allow the | |
| application to be built. Usually, this section is not needed. When building | |
| code from external sources, though, it may be necessary to disable some | |
| warnings or enable/disable some compiler features. | |
| IMPLEMENTATION-Specific Features | |
| ================================ | |
| It is very strongly recommended that applications not use the long or | |
| unsigned long types. The size of this type varies between compilers and is one | |
| of the less portable aspects of C. Instead, one should use the UEFI defined | |
| types whenever possible. Use of these types, listed below for reference, | |
| ensures that the declared objects have unambiguous, explicitly declared, sizes | |
| and characteristics. | |
| UINT64 INT64 UINT32 INT32 UINT16 CHAR16 | |
| INT16 BOOLEAN UINT8 CHAR8 INT8 | |
| UINTN INTN PHYSICALADDRESS | |
| There are similar types declared in sys/types.h and related files. | |
| The types UINTN and INTN have the native width of the target processor | |
| architecture. Thus, INTN on IA32 has a width of 32 bits while INTN on X64 and | |
| IPF has a width of 64 bits. | |
| For maximum portability, data objects intended to hold addresses should be | |
| declared with type intptr_t or uintptr_t. These types, declared in | |
| sys/stdint.h, can be used to create objects capable of holding pointers. Note | |
| that these types will generate different sized objects on different processor | |
| architectures. If a constant size across all processors and compilers is | |
| needed, use type PHYSICAL_ADDRESS. | |
| Though not specifically required by the ISO/IEC 9899 standard, this | |
| implementation of the Standard C Library provides the following system calls | |
| which are declared in sys/EfiSysCall.h. | |
| close dup dup2 fcntl | |
| fstat getcwd ioctl isatty | |
| lseek lstat mkdir open | |
| poll read rename rmdir | |
| stat unlink write | |
| The open function will accept file names of "stdin:", "stdout:", and "stderr:" | |
| which cause the respective streams specified in the UEFI System Table to be | |
| opened. Normally, these are associated with the console device. When the | |
| application is first started, these streams are automatically opened on File | |
| Descriptors 0, 1, and 2 respectively. | |