[PATCH v1 2/6] ArmVirtPkg: Add Platform CI and configuration for Core CI

["Michael Kubacki" <michael.kubacki@outlook.com>]

From: Sean Brogan <sean.brogan@microsoft.com>

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2570

Add new Azure Pipeline definitions to build and run ArmVirtPkg with:
  * Ubuntu GCC5
Add PyTool based build of ArmVirtPkg
Add extdep for managing the iasl dependency
Add ArmVirtPkg.ci.yaml for Core CI
Add README-pytools for details and instructions

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Leif Lindholm <leif@nuviainc.com>
Signed-off-by: Sean Brogan <sean.brogan@microsoft.com>
---
 ArmVirtPkg/.azurepipelines/Ubuntu-GCC5.yml |  89 +++++++
 ArmVirtPkg/ArmVirtPkg.ci.yaml              | 103 ++++++++
 ArmVirtPkg/PlatformBuild.py                | 263 ++++++++++++++++++++
 ArmVirtPkg/README-pytools.md               | 123 +++++++++
 ArmVirtPkg/iasl_ext_dep.yaml               |  21 ++
 5 files changed, 599 insertions(+)

diff --git a/ArmVirtPkg/.azurepipelines/Ubuntu-GCC5.yml b/ArmVirtPkg/.azurepipelines/Ubuntu-GCC5.yml
new file mode 100644
index 000000000000..ef5b61a0d4df
--- /dev/null
+++ b/ArmVirtPkg/.azurepipelines/Ubuntu-GCC5.yml
@@ -0,0 +1,89 @@
+## @file
+# Azure Pipeline build file for building a platform.
+#
+# Platform: ArmVirtQemu
+# OS: Ubuntu
+# Toolchain: GCC5
+#
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+trigger:
+  - master
+pr:
+  - master
+
+jobs:
+  - job: Platform_CI
+    variables:
+      package: 'ArmVirtPkg'
+      vm_image: 'ubuntu-latest'
+      should_run: true
+      run_flags: "MAKE_STARTUP_NSH=TRUE QEMU_HEADLESS=TRUE"
+
+    #Use matrix to speed up the build process
+    strategy:
+        matrix:
+          QEMU_AARCH64_DEBUG:
+            Build.File: "$(package)/PlatformBuild.py"
+            Build.Arch: "AARCH64"
+            Build.Flags: ""
+            Build.Target: "DEBUG"
+            Run.Flags: $(run_flags)
+            Run: $(should_run)
+          QEMU_AARCH64_RELEASE:
+            Build.File: "$(package)/PlatformBuild.py"
+            Build.Arch: "AARCH64"
+            Build.Flags: ""
+            Build.Target: "RELEASE"
+            Run.Flags: $(run_flags)
+            Run: $(should_run)
+          QEMU_AARCH64_NOOPT:
+            Build.File: "$(package)/PlatformBuild.py"
+            Build.Arch: "AARCH64"
+            Build.Flags: ""
+            Build.Target: "NOOPT"
+            Run.Flags: $(run_flags)
+            Run: $(should_run)
+          QEMU_ARM_DEBUG:
+            Build.File: "$(package)/PlatformBuild.py"
+            Build.Arch: "ARM"
+            Build.Flags: ""
+            Build.Target: "DEBUG"
+            Run.Flags: $(run_flags)
+            Run: $(should_run)
+          QEMU_ARM_RELEASE:
+            Build.File: "$(package)/PlatformBuild.py"
+            Build.Arch: "ARM"
+            Build.Flags: ""
+            Build.Target: "RELEASE"
+            Run.Flags: $(run_flags)
+            Run: $(should_run)
+          QEMU_ARM_NOOPT:
+            Build.File: "$(package)/PlatformBuild.py"
+            Build.Arch: "ARM"
+            Build.Flags: ""
+            Build.Target: "NOOPT"
+            Run.Flags: $(run_flags)
+            Run: $(should_run)
+
+    workspace:
+      clean: all
+
+    pool:
+      vmImage: $(vm_image)
+
+    steps:
+    - template: ../../.azurepipelines/templates/platform-build-run-steps.yml
+      parameters:
+        tool_chain_tag: GCC5
+        build_pkg: $(package)
+        build_target: $(Build.Target)
+        build_arch: $(Build.Arch)
+        build_file: $(Build.File)
+        build_flags: $(Build.Flags)
+        run_flags: $(Run.Flags)
+        extra_install_step:
+        - bash: sudo apt-get install qemu
+          displayName: Install qemu
+          condition: and(gt(variables.pkg_count, 0), succeeded())
diff --git a/ArmVirtPkg/ArmVirtPkg.ci.yaml b/ArmVirtPkg/ArmVirtPkg.ci.yaml
new file mode 100644
index 000000000000..4553725ee528
--- /dev/null
+++ b/ArmVirtPkg/ArmVirtPkg.ci.yaml
@@ -0,0 +1,103 @@
+## @file
+# Core CI configuration for ArmVirtPkg
+#
+# ArmVirtPkg is part of Platform Ci for builds so this is only
+# used for code analysis.
+#
+# Copyright (c) Microsoft Corporation
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+{
+    ## options defined .pytool/Plugin/CompilerPlugin
+    "CompilerPlugin": {
+        "DscPath": "" # Don't support this test
+    },
+
+    ## options defined .pytool/Plugin/HostUnitTestCompilerPlugin
+    "HostUnitTestCompilerPlugin": {
+        "DscPath": "" # Don't support this test
+    },
+
+    ## options defined .pytool/Plugin/CharEncodingCheck
+    "CharEncodingCheck": {
+        "IgnoreFiles": []
+    },
+
+    ## options defined .pytool/Plugin/DependencyCheck
+    "DependencyCheck": {
+        "AcceptableDependencies": [
+            "MdePkg/MdePkg.dec",
+            "MdeModulePkg/MdeModulePkg.dec",
+            "ArmVirtPkg/ArmVirtPkg.dec",
+            "NetworkPkg/NetworkPkg.dec",
+            "ArmPkg/ArmPkg.dec",
+            "OvmfPkg/OvmfPkg.dec",
+            "EmbeddedPkg/EmbeddedPkg.dec",
+            "ArmPlatformPkg/ArmPlatformPkg.dec",
+            "SecurityPkg/SecurityPkg.dec",
+            "ShellPkg/ShellPkg.dec"  #Is this ok?
+        ],
+        # For host based unit tests
+        "AcceptableDependencies-HOST_APPLICATION":[
+            "UnitTestFrameworkPkg/UnitTestFrameworkPkg.dec"
+        ],
+        # For UEFI shell based apps
+        "AcceptableDependencies-UEFI_APPLICATION":[
+
+        ],
+        "IgnoreInf": []
+    },
+
+    ## options defined .pytool/Plugin/DscCompleteCheck
+    "DscCompleteCheck": {
+        "IgnoreInf": [""],
+        "DscPath": ""  # Don't support this test
+    },
+
+    ## options defined .pytool/Plugin/HostUnitTestDscCompleteCheck
+    "HostUnitTestDscCompleteCheck": {
+        "IgnoreInf": [""],
+        "DscPath": "" # Don't support this test
+    },
+
+    ## options defined .pytool/Plugin/GuidCheck
+    "GuidCheck": {
+        "IgnoreGuidName": [],
+        "IgnoreGuidValue": [],
+        "IgnoreFoldersAndFiles": [],
+        "IgnoreDuplicates": [],
+    },
+
+    ## options defined .pytool/Plugin/LibraryClassCheck
+    "LibraryClassCheck": {
+        "IgnoreHeaderFile": []
+    },
+
+    ## options defined .pytool/Plugin/SpellCheck
+    "SpellCheck": {
+        "AuditOnly": False,           # Fails right now with over 270 errors
+        "IgnoreFiles": [],           # use gitignore syntax to ignore errors in matching files
+        "ExtendWords": [
+            "setjump",
+            "plong",
+            "lparam",
+            "lpdword",
+            "lpthread",
+            "lresult",
+            "bootable",
+            "bsymbolic",
+            "endiannness",
+            "fvmain",
+            "multiboot",
+            "qemu's",
+            "ramdisk",
+            "ramfb",
+            "unbootable",
+            "virt's",
+            "werror",
+            "xenio"
+        ],           # words to extend to the dictionary for this package
+        "IgnoreStandardPaths": [],   # Standard Plugin defined paths that should be ignore
+        "AdditionalIncludePaths": [] # Additional paths to spell check (wildcards supported)
+    }
+}
diff --git a/ArmVirtPkg/PlatformBuild.py b/ArmVirtPkg/PlatformBuild.py
new file mode 100644
index 000000000000..c2c5cd098e7e
--- /dev/null
+++ b/ArmVirtPkg/PlatformBuild.py
@@ -0,0 +1,263 @@
+# @file
+# Script to Build ArmVirtPkg UEFI firmware
+#
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+import os
+import logging
+
+from edk2toolext.environment import shell_environment
+from edk2toolext.environment.uefi_build import UefiBuilder
+from edk2toolext.invocables.edk2_platform_build import BuildSettingsManager
+from edk2toolext.invocables.edk2_setup import SetupSettingsManager, RequiredSubmodule
+from edk2toolext.invocables.edk2_update import UpdateSettingsManager
+from edk2toolext.invocables.edk2_pr_eval import PrEvalSettingsManager
+from edk2toollib.utility_functions import RunCmd
+from edk2toollib.utility_functions import GetHostInfo
+
+# ####################################################################################### #
+#                                Common Configuration                                     #
+# ####################################################################################### #
+
+
+class CommonPlatform():
+    ''' Common settings for this platform.  Define static data here and use
+        for the different parts of stuart
+    '''
+    PackagesSupported = ("ArmVirtPkg",)
+    ArchSupported = ("AARCH64", "ARM")
+    TargetsSupported = ("DEBUG", "RELEASE", "NOOPT")
+    Scopes = ('armvirt', 'edk2-build')
+    WorkspaceRoot = os.path.realpath(os.path.join(
+        os.path.dirname(os.path.abspath(__file__)), ".."))
+
+    # ####################################################################################### #
+    #                         Configuration for Update & Setup                                #
+    # ####################################################################################### #
+
+
+class SettingsManager(UpdateSettingsManager, SetupSettingsManager, PrEvalSettingsManager):
+
+    def GetPackagesSupported(self):
+        ''' return iterable of edk2 packages supported by this build.
+        These should be edk2 workspace relative paths '''
+        return CommonPlatform.PackagesSupported
+
+    def GetArchitecturesSupported(self):
+        ''' return iterable of edk2 architectures supported by this build '''
+        return CommonPlatform.ArchSupported
+
+    def GetTargetsSupported(self):
+        ''' return iterable of edk2 target tags supported by this build '''
+        return CommonPlatform.TargetsSupported
+
+    def GetRequiredSubmodules(self):
+        ''' return iterable containing RequiredSubmodule objects.
+        If no RequiredSubmodules return an empty iterable
+        '''
+        rs = []
+        rs.append(RequiredSubmodule(
+            "ArmPkg/Library/ArmSoftFloatLib/berkeley-softfloat-3", False))
+        rs.append(RequiredSubmodule(
+            "CryptoPkg/Library/OpensslLib/openssl", False))
+        return rs
+
+    def SetArchitectures(self, list_of_requested_architectures):
+        ''' Confirm the requests architecture list is valid and configure SettingsManager
+        to run only the requested architectures.
+
+        Raise Exception if a list_of_requested_architectures is not supported
+        '''
+        unsupported = set(list_of_requested_architectures) - \
+            set(self.GetArchitecturesSupported())
+        if(len(unsupported) > 0):
+            errorString = (
+                "Unsupported Architecture Requested: " + " ".join(unsupported))
+            logging.critical(errorString)
+            raise Exception(errorString)
+        self.ActualArchitectures = list_of_requested_architectures
+
+    def GetWorkspaceRoot(self):
+        ''' get WorkspacePath '''
+        return CommonPlatform.WorkspaceRoot
+
+    def GetActiveScopes(self):
+        ''' return tuple containing scopes that should be active for this process '''
+
+        scopes = CommonPlatform.Scopes
+        ActualToolChainTag = shell_environment.GetBuildVars().GetValue("TOOL_CHAIN_TAG", "")
+
+        if GetHostInfo().os.upper() == "LINUX" and ActualToolChainTag.upper().startswith("GCC"):
+            if "AARCH64" in self.ActualArchitectures:
+                scopes += ("gcc_aarch64_linux",)
+            if "ARM" in self.ActualArchitectures:
+                scopes += ("gcc_arm_linux",)
+        return scopes
+
+    def FilterPackagesToTest(self, changedFilesList: list, potentialPackagesList: list) -> list:
+        ''' Filter other cases that this package should be built
+        based on changed files. This should cover things that can't
+        be detected as dependencies. '''
+        build_these_packages = []
+        possible_packages = potentialPackagesList.copy()
+        for f in changedFilesList:
+            # BaseTools files that might change the build
+            if "BaseTools" in f:
+                if os.path.splitext(f) not in [".txt", ".md"]:
+                    build_these_packages = possible_packages
+                    break
+
+            # if the azure pipeline file changed
+            if ".azurepipelines" in f and "ArmVirt" in f:
+                build_these_packages = possible_packages
+                break
+
+            # if the azure pipeline platform template file changed
+            if ".azurepipelines" in f and "platforms" in f and "templates" in f:
+                build_these_packages = possible_packages
+                break
+
+        return build_these_packages
+
+    def GetPlatformDscAndConfig(self) -> tuple:
+        ''' If a platform desires to provide its DSC then Policy 4 will evaluate if
+        any of the changes will be built in the dsc.
+
+        The tuple should be (<workspace relative path to dsc file>, <input dictionary of dsc key value pairs>)
+        '''
+        return (os.path.join("ArmVirtPkg", "ArmVirtQemu.dsc"), {})
+
+
+    # ####################################################################################### #
+    #                         Actual Configuration for Platform Build                         #
+    # ####################################################################################### #
+
+
+class PlatformBuilder(UefiBuilder, BuildSettingsManager):
+    def __init__(self):
+        UefiBuilder.__init__(self)
+
+    def AddCommandLineOptions(self, parserObj):
+        ''' Add command line options to the argparser '''
+        parserObj.add_argument('-a', "--arch", dest="build_arch", type=str, default="AARCH64",
+                               help="Optional - Architecture to build.  Default = AARCH64")
+
+    def RetrieveCommandLineOptions(self, args):
+        '''  Retrieve command line options from the argparser '''
+
+        shell_environment.GetBuildVars().SetValue(
+            "TARGET_ARCH", args.build_arch.upper(), "From CmdLine")
+
+        shell_environment.GetBuildVars().SetValue(
+            "ACTIVE_PLATFORM", "ArmVirtPkg/ArmVirtQemu.dsc", "From CmdLine")
+
+    def GetWorkspaceRoot(self):
+        ''' get WorkspacePath '''
+        return CommonPlatform.WorkspaceRoot
+
+    def GetPackagesPath(self):
+        ''' Return a list of workspace relative paths that should be mapped as edk2 PackagesPath '''
+        return ()
+
+    def GetActiveScopes(self):
+        ''' return tuple containing scopes that should be active for this process '''
+        scopes = CommonPlatform.Scopes
+        ActualToolChainTag = shell_environment.GetBuildVars().GetValue("TOOL_CHAIN_TAG", "")
+        Arch = shell_environment.GetBuildVars().GetValue("TARGET_ARCH", "")
+
+        if GetHostInfo().os.upper() == "LINUX" and ActualToolChainTag.upper().startswith("GCC"):
+            if "AARCH64" == Arch:
+                scopes += ("gcc_aarch64_linux",)
+            elif "ARM" == Arch:
+                scopes += ("gcc_arm_linux",)
+        return scopes
+
+    def GetName(self):
+        ''' Get the name of the repo, platform, or product being build '''
+        ''' Used for naming the log file, among others '''
+        # check the startup nsh flag and if set then rename the log file.
+        # this helps in CI so we don't overwrite the build log since running
+        # uses the stuart_build command.
+        if(shell_environment.GetBuildVars().GetValue("MAKE_STARTUP_NSH", "FALSE") == "TRUE"):
+            return "ArmVirtPkg_With_Run"
+        return "ArmVirtPkg"
+
+    def GetLoggingLevel(self, loggerType):
+        ''' Get the logging level for a given type
+        base == lowest logging level supported
+        con  == Screen logging
+        txt  == plain text file logging
+        md   == markdown file logging
+        '''
+        return logging.DEBUG
+
+    def SetPlatformEnv(self):
+        logging.debug("PlatformBuilder SetPlatformEnv")
+        self.env.SetValue("PRODUCT_NAME", "ArmVirtQemu", "Platform Hardcoded")
+        self.env.SetValue("MAKE_STARTUP_NSH", "FALSE", "Default to false")
+        self.env.SetValue("QEMU_HEADLESS", "FALSE", "Default to false")
+        return 0
+
+    def PlatformPreBuild(self):
+        return 0
+
+    def PlatformPostBuild(self):
+        return 0
+
+    def FlashRomImage(self):
+        VirtualDrive = os.path.join(self.env.GetValue(
+            "BUILD_OUTPUT_BASE"), "VirtualDrive")
+        os.makedirs(VirtualDrive, exist_ok=True)
+        OutputPath_FV = os.path.join(
+            self.env.GetValue("BUILD_OUTPUT_BASE"), "FV")
+        Built_FV = os.path.join(OutputPath_FV, "QEMU_EFI.fd")
+
+        # pad fd to 64mb
+        with open(Built_FV, "ab") as fvfile:
+            fvfile.seek(0, os.SEEK_END)
+            additional = b'\0' * ((64 * 1024 * 1024)-fvfile.tell())
+            fvfile.write(additional)
+
+        # QEMU must be on that path
+
+        # Unique Command and Args parameters per ARCH
+        if (self.env.GetValue("TARGET_ARCH").upper() == "AARCH64"):
+            cmd = "qemu-system-aarch64"
+            args = "-M virt"
+            args += " -cpu cortex-a57"                                          # emulate cpu
+        elif(self.env.GetValue("TARGET_ARCH").upper() == "ARM"):
+            cmd = "qemu-system-arm"
+            args = "-M virt"
+            args += " -cpu cortex-a15"                                          # emulate cpu
+        else:
+            raise NotImplementedError()
+
+        # Common Args
+        args += " -pflash " + Built_FV                                     # path to fw
+        args += " -m 1024"                                                  # 1gb memory
+        # turn off network
+        args += " -net none"
+        # Serial messages out
+        args += " -serial stdio"
+        # Mount disk with startup.nsh
+        args += f" -drive file=fat:rw:{VirtualDrive},format=raw,media=disk"
+
+        # Conditional Args
+        if (self.env.GetValue("QEMU_HEADLESS").upper() == "TRUE"):
+            args += " -display none"  # no graphics
+
+        if (self.env.GetValue("MAKE_STARTUP_NSH").upper() == "TRUE"):
+            f = open(os.path.join(VirtualDrive, "startup.nsh"), "w")
+            f.write("BOOT SUCCESS !!! \n")
+            # add commands here
+            f.write("reset -s\n")
+            f.close()
+
+        ret = RunCmd(cmd, args)
+
+        if ret == 0xc0000005:
+            # for some reason getting a c0000005 on successful return
+            return 0
+
+        return ret
diff --git a/ArmVirtPkg/README-pytools.md b/ArmVirtPkg/README-pytools.md
new file mode 100644
index 000000000000..ea70018e510a
--- /dev/null
+++ b/ArmVirtPkg/README-pytools.md
@@ -0,0 +1,123 @@
+# ArmVirtPkg
+
+This README-pytools.md summarizes the current state of Platform CI for ArmVirtPkg.  It also describes how to _build_ ArmVirtPkg using the Pytools build system.
+
+## Platform CI Current Status
+
+<table>
+  <tr>
+    <th>Config</th>
+    <th colspan="3">Build & Run</th>
+    <th>Notes</th>
+  </tr>
+  <tr>
+    <th></th>
+    <th>DEBUG</th>
+    <th>RELEASE</th>
+    <th>NOOPT</th>
+    <th></th>
+  </tr>
+  <tr>
+    <th colspan="5" align="left">
+    Ubuntu 18.04 GCC5
+    </th>
+  </tr>
+  <tr>
+    <td>AARCH64</td>
+    <td>
+      <a  href="https://dev.azure.com/tianocore/edk2-ci-play/_build/latest?definitionId=41&branchName=master">
+      <img src="https://dev.azure.com/tianocore/edk2-ci-play/_apis/build/status/ArmVirtPkg/ArmVirtQemu%20Ubuntu%20GCC5?branchName=master&jobName=Platform_CI&configuration=Platform_CI%20QEMU_AARCH64_DEBUG"/></a>
+    </td>
+    <td>
+      <a  href="https://dev.azure.com/tianocore/edk2-ci-play/_build/latest?definitionId=41&branchName=master">
+      <img src="https://dev.azure.com/tianocore/edk2-ci-play/_apis/build/status/ArmVirtPkg/ArmVirtQemu%20Ubuntu%20GCC5?branchName=master&jobName=Platform_CI&configuration=Platform_CI%20QEMU_AARCH64_RELEASE"/></a>
+    </td>
+    <td>
+      <a  href="https://dev.azure.com/tianocore/edk2-ci-play/_build/latest?definitionId=41&branchName=master">
+      <img src="https://dev.azure.com/tianocore/edk2-ci-play/_apis/build/status/ArmVirtPkg/ArmVirtQemu%20Ubuntu%20GCC5?branchName=master&jobName=Platform_CI&configuration=Platform_CI%20QEMU_AARCH64_NOOPT"/></a>
+    </td>
+    <td></td>
+  </tr>
+  <tr>
+    <td>ARM</td>
+    <td>
+      <a  href="https://dev.azure.com/tianocore/edk2-ci-play/_build/latest?definitionId=41&branchName=master">
+      <img src="https://dev.azure.com/tianocore/edk2-ci-play/_apis/build/status/ArmVirtPkg/ArmVirtQemu%20Ubuntu%20GCC5?branchName=master&jobName=Platform_CI&configuration=Platform_CI%20QEMU_ARM_DEBUG"/></a>
+    </td>
+    <td>
+      <a  href="https://dev.azure.com/tianocore/edk2-ci-play/_build/latest?definitionId=41&branchName=master">
+      <img src="https://dev.azure.com/tianocore/edk2-ci-play/_apis/build/status/ArmVirtPkg/ArmVirtQemu%20Ubuntu%20GCC5?branchName=master&jobName=Platform_CI&configuration=Platform_CI%20QEMU_ARM_RELEASE"/></a>
+    </td>
+    <td>
+      <a  href="https://dev.azure.com/tianocore/edk2-ci-play/_build/latest?definitionId=41&branchName=master">
+      <img src="https://dev.azure.com/tianocore/edk2-ci-play/_apis/build/status/ArmVirtPkg/ArmVirtQemu%20Ubuntu%20GCC5?branchName=master&jobName=Platform_CI&configuration=Platform_CI%20QEMU_ARM_NOOPT"/></a>
+    </td>
+    <td></td>
+  </tr>
+</table>
+
+### Config Details
+
+| Config       | Architectures      |Additional Flags |
+| :----        | :-----             | :----           |
+| AARCH64      | AARCH64            | None            |
+| ARM          | ARM                | None            |
+
+## Setup
+
+### The Usual EDK2 Build Setup
+
+- [Python 3.8.x - Download & Install](https://www.python.org/downloads/)
+- [GIT - Download & Install](https://git-scm.com/download/)
+- [GIT - Configure for EDK II](https://github.com/tianocore/tianocore.github.io/wiki/Windows-systems#github-help)
+- [QEMU - Download, Install, and add to your path](https://www.qemu.org/download/)
+- [EDKII Source - Download/Checkout from Github](https://github.com/tianocore/tianocore.github.io/wiki/Windows-systems#download)
+  - **NOTE:** Do _not_ follow the EDK II Compile Tools and Build instructions, see below...
+
+### Differences from EDK Classic Build Setup
+
+- Build BaseTools using "`C:\git\edk2>python BaseTools\Edk2ToolsBuild.py [-t <ToolChainTag>]`"
+  - This replaces "`edksetup Rebuild`" from the classic build system
+  - For Windows `<ToolChainTag>` examples, refer to [Windows ToolChain Matrix](https://github.com/tianocore/tianocore.github.io/wiki/Windows-systems-ToolChain-Matrix), defaults to `VS2017` if not specified
+- **No Action:** Submodule initialization and manual installation/setup of NASM and iASL is **not** required, it is handled by the PyTools build system
+
+### Building with Pytools for ArmVirtPkg
+
+- Install Pytools
+  - `pip install --upgrade -r pip-requirements.txt`
+- Initialize & Update Submodules
+  - `stuart_setup -c ArmVirt\PlatformBuild.py TOOL_CHAIN_TAG=<TOOL_CHAIN_TAG> -a <TARGET_ARCH>`
+- Initialize & Update Dependencies (e.g. iASL, NASM & GCC Arm/Aarch64 Compilers)
+  - `stuart_update -c ArmVirtPkg\PlatformBuild.py TOOL_CHAIN_TAG=<TOOL_CHAIN_TAG> -a <TARGET_ARCH>`
+- Compile (AARCH64 supported / ARM support coming soon)
+  - `stuart_build -c ArmVirtPkg\PlatformBuild.py TOOL_CHAIN_TAG=<TOOL_CHAIN_TAG> -a <TARGET_ARCH>`
+- Running Emulator
+  - You can add `--FlashRom` to the end of your build command and the emulator will run after the build is complete.
+  - or use the FlashOnly feature like `stuart_build -c ArmVirtPkg\PlatformBuild.py TOOL_CHAIN_TAG=<TOOL_CHAIN_TAG> -a <TARGET_ARCH> --FlashOnly` to just run the emulator.
+
+### Notes
+
+1. Including the expected build architecture and toolchain to the _stuart_update_ command is critical. This is because there are extra scopes and tools that will be resolved during the update step that need to match your build step.
+2. Configuring _ACTIVE_PLATFORM_ and _TARGET_ARCH_ in Conf/target.txt is _not_ required. This environment is set by PlatformBuild.py based upon the "`[-a <TARGET_ARCH>]`" parameter.
+3. QEMU must be on your path.  On Windows this is a manual process and not part of the QEMU installer.
+
+**NOTE:** Logging the execution output will be in the normal stuart log as well as to your console.
+
+## Custom Build Options
+
+**MAKE_STARTUP_NSH=TRUE** will output a _startup.nsh_ file to the location mapped as fs0. This is used in CI in combination with the --FlashOnly feature to run QEMU to the UEFI shell and then execute the contents of startup.nsh.
+
+**QEMU_HEADLESS=TRUE** Since CI servers run headless QEMU must be told to run with no display otherwise an error occurs. Locally you don't need to set this.
+
+## Passing Build Defines
+
+To pass build defines through _stuart_build_, prepend `BLD_*_`to the define name and pass it on the command-line. _stuart_build_ currently requires values to be assigned, so add an`=1` suffix for bare defines.
+For example, to enable the TPM2 support, instead of the traditional "-D TPM2_ENABLE=TRUE", the stuart_build command-line would be:
+
+`stuart_build -c ArmVirtPkg/PlatformBuild.py BLD_*_TPM2_ENABLE=TRUE`
+
+## References
+
+- [Installing Pytools](https://github.com/tianocore/edk2-pytool-extensions/blob/master/docs/using.md#installing)
+- For each workspace, consider creating & using a [Python Virtual Environment](https://docs.python.org/3/library/venv.html). For example <https://microsoft.github.io/mu/CodeDevelopment/prerequisites/#workspace-virtual-environment-setup-process>
+- [stuart_build command-line parser](https://github.com/tianocore/edk2-pytool-extensions/blob/56f6a7aee09995c2f22da4765e8b0a29c1cbf5de/edk2toolext/edk2_invocable.py#L109)
diff --git a/ArmVirtPkg/iasl_ext_dep.yaml b/ArmVirtPkg/iasl_ext_dep.yaml
new file mode 100644
index 000000000000..8869ed3ecef1
--- /dev/null
+++ b/ArmVirtPkg/iasl_ext_dep.yaml
@@ -0,0 +1,21 @@
+## @file
+# Download iasl executable tool from a nuget.org package
+# - package contains different binaries based on host
+# Add the folder with the tool to the path
+#
+# This is only downloaded for scope armvirt thus
+# should have no impact on the asl compiler used by any
+# other platform build
+#
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+{
+  "id": "iasl-armvirt-1",
+  "scope": "armvirt",
+  "type": "nuget",
+  "name": "iasl",
+  "source": "https://api.nuget.org/v3/index.json",
+  "version": "20190215.0.0",
+  "flags": ["set_path", "host_specific"],
+}
-- 
2.16.3.windows.1