Hi UEFI community,

I’d like to inform you about an update in the CdePkg branch of  edk2-staging.

https://github.com/tianocore/edk2-staging/tree/CdePkg#cdepkg

The goal of the CdePkg is to provide an ANSI C Interface for UEFI POST drivers,

that enables BIOS engineers to (more) easily port standard C programs or libraries

(e.g. the openSSL library, already done) to POST drivers.

Furthermore the ANSI C Interface is disseminated widely, also it’s bugs and pitfalls are known very well

by a broad range of IT professionals and may help to be better supportable by the open source initiative

compared to the proprietary interface that is available today in Tianocore UEFI.

Now the ANSI C function clock() is introduced for PEI and DXE.

Currently there are 4 examples implemented:

1. argvc: https://github.com/tianocore/edk2-staging/blob/CdePkg/CdeValidationPkg/HOSTED_ENV/argcv/main.c#L57

argc/argv handling according to https://msdn.microsoft.com/en-us/library/a1y7w461.aspx

2. systeminterfacePEI: https://github.com/tianocore/edk2-staging/blob/CdePkg/CdeValidationPkg/SYSTEM_IF/systeminterfacePEI/main.c#L57

demonstration, how PeiServices and FileHandle are passed into main()

3. systeminterfaceDXE: https://github.com/tianocore/edk2-staging/blob/CdePkg/CdeValidationPkg/SYSTEM_IF/systeminterfaceDXE/main.c#L57

demonstration, how SystemTable and ImageHandle are passed into main()

ANSI C LIBRARY functions:

4. NEW: time.h clock(): https://github.com/tianocore/edk2-staging/blob/CdePkg/CdeValidationPkg/TIME_H/clock/main.c#L1

for PEI and DXE phase. It provides TSC based, millisecond precise, exact and chipset independent clock() function.

(NOTE: in emulation mode the TSC nominal frequency is supposed to be 1GHz)

https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/clock?view=vs-2019

Best Regards,

Kilian

From: Kilian Kegel
Sent: Wednesday, October 23, 2019 10:03 PM
To: devel@edk2.groups.io
Cc: Kinney, Michael D; Richardson, Brian
Subject: [edk2-devel] [staging/branch]: CdePkg - C Development Environment Package

Hi UEFI community,

I’d like to introduce the CdePkg to edk2-staging.

Some time ago I decided to write my own ANSI C Library for UEFI Shell and POST.

The UEFI Shell library (“Torito C Library”) has been production-ready for more than one year.

The POST version of the library (“CdeLib”) is not yet fully tested.

I will be demonstrating my verification procedure in the upcoming weeks on EDK2 STAGING  https://github.com/tianocore/edk2-staging/tree/CdePkg

Currently there are 3 examples implemented:

5. argvc: https://github.com/tianocore/edk2-staging/blob/CdePkg/CdeValidationPkg/HOSTED_ENV/argcv/main.c#L57

argc/argv handling according to https://msdn.microsoft.com/en-us/library/a1y7w461.aspx

6. systeminterfacePEI: https://github.com/tianocore/edk2-staging/blob/CdePkg/CdeValidationPkg/SYSTEM_IF/systeminterfacePEI/main.c#L57

demonstration, how PeiServices and FileHandle are passed into main()

7. systeminterfaceDXE: https://github.com/tianocore/edk2-staging/blob/CdePkg/CdeValidationPkg/SYSTEM_IF/systeminterfaceDXE/main.c#L57

demonstration, how SystemTable and ImageHandle are passed into main()

Upcoming next demonstration will be the clock() function end of this week

The idea is to bring the ANSI C Library interface into POST drivers.

This will:

1. ease porting tasks
2. allow cross development
3. allow developers to focus on their aims, because they aren’t forced to keep in mind a lot of additional info (e.g. RShiftU64)
4. provide all intrisics to allow the compiler to be a “C compiler”

(e.g. char buffer[256] = { 1 };)

What is CdePkg and Torito C Library?

• CdePkg and Torito C Library are a one man show / after work party, that is owned and written solely by myself
• CdePkg is a reference implementation only for Microsoft C compiler
• CdePkg is a feasibility study
• CdePkg is the successor of Torito C, based on the same source code
• CdePkg C Development Environment is similar to  MdePkg Module Development Environment

but guarantees  that the C compiler is always fully usable (all intrinsics available) and the C90/C95 standard library is always available

What are the design goals?

• to rewrite the whole thing from scratch, without using any public source code from GNU, BSD, Watcom
• completeness: full blown C90 + C95 support, as lowest common denominator
• tailored for UEFI: small code size, for UEFI-POST-driver uses a C-Library-Driver, that contains core/worker functions for realloc() ==  malloc() and free(),

entire printf()-family, entire scanf()-family.

UEFI-POST-driver just uses small wrapper functions to run the C-Library-Driver code.

• stable, exact, chipset independent TSC based clock() with CLOCKS_PER_SEC == 1000
• complete set of the Microsoft C-compiler intrinsic functions
• ROM-able! Runs with stack but w/o any static storage duration in .data segment, e.g. for rand(), strtok(), tmpfile()

This is required for early PEI before memory sizing, when PEI-images run directly out of flash

• Microsoft (bug) compatible (as far as possible)

1. use original Microsoft header files for UEFI Shell Apps created in VS2019
2. allow expensive debugging tasks of ANSI C .EFI applications in Visual Studio in its Windows NT counter part
3. to save my lifetime writing a documentation https://github.com/tianocore/edk2-staging/tree/CdePkg/implemented.md#validation-status

• all the above in one single C-Library CdeLib.lib

CdePkg shall be adjusted to other compilers/tool chains too, once it is feature-complete and accepted by the UEFI community.

As long as it is for Microsoft VS2019 only.

CdePkg README.md is here: https://github.com/tianocore/edk2-staging/tree/CdePkg#cdepkg

CdePkg HOWTO is here: https://github.com/tianocore/edk2-staging/blob/CdePkg/README.md#howto

CdeValidationPkg README.md is here: https://github.com/tianocore/edk2-staging/blob/CdePkg/CdeValidationPkg/README.md

CdeValidationPkg HOWTO is here: https://github.com/tianocore/edk2-staging/blob/CdePkg/CdeValidationPkg/README.md

HOWTO:

1. clone the edk2-staging repository
2. checkout CdePkg
3. run LAUNCH.BAT
4. run build -p EmulatorPkg\EmulatorPkg.dsc -t VS2015x86 -a IA32
5. run DBGEMU.BAT to start emulation (EmulatorPkg)
6. run build -a IA32 -a X64 -n 5 -t VS2015x86 -b DEBUG -p Vlv2TbltDevicePkg\PlatformPkgX64.dsc
7. update MinnowBoard with Build/Vlv2TbltDevicePkgX64\DEBUG_VS2015x86\FV\VLV.fd

Best regards,

Kilian Kegel