Currently, this project can be built with edk2-version: edk2-stable202108.
1, get ready for UEFI development: https://github.com/tianocore/edk2
2, copy KrishnaTestPkg to your workspace.
3, run "edksetup.bat" to construct build environment.
4, read KrishnaTestPkg\KrishnaTestPkg.dsc to fix dependencies for some tools.
5, run "build -p KrishnaTestPkg\KrishnaTestPkg.dsc -a X64" to build it.
regex.efi has dependency: https://github.com/kokke/tiny-regex-c
xdb.efi has dependency: https://github.com/akheron/jansson
history.efi has got some idea from Z.t(http://www.lab-z.com/)
Thanks to all the people behind them.