Import code from old v4 repo

4 files changed, 738 insertions, 0 deletions

diff --git a/src/mbahost/host.cpp b/src/mbahost/host.cpp
new file mode 100644
index 00000000..694db357
--- /dev/null
+++ b/src/mbahost/host.cpp
@@ -0,0 +1,656 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+#include "precomp.h"
+#include <BootstrapperCore.h> // includes the generated assembly name macros.
+#include "BalBaseBootstrapperApplicationProc.h"
+
+static const DWORD NET452_RELEASE = 379893;
+
+using namespace mscorlib;
+
+extern "C" typedef HRESULT (WINAPI *PFN_CORBINDTOCURRENTRUNTIME)(
+    __in LPCWSTR pwszFileName,
+    __in REFCLSID rclsid,
+    __in REFIID riid,
+    __out LPVOID *ppv
+    );
+
+extern "C" typedef HRESULT(WINAPI *PFN_MBAPREQ_BOOTSTRAPPER_APPLICATION_CREATE)(
+    __in HRESULT hrHostInitialization,
+    __in IBootstrapperEngine* pEngine,
+    __in const BOOTSTRAPPER_CREATE_ARGS* pArgs,
+    __inout BOOTSTRAPPER_CREATE_RESULTS* pResults
+    );
+
+static HINSTANCE vhInstance = NULL;
+static ICorRuntimeHost *vpCLRHost = NULL;
+static _AppDomain *vpAppDomain = NULL;
+static HMODULE vhMbapreqModule = NULL;
+
+
+// internal function declarations
+
+static HRESULT GetAppDomain(
+    __out _AppDomain** ppAppDomain
+    );
+static HRESULT GetAppBase(
+    __out LPWSTR* psczAppBase
+    );
+static HRESULT CheckSupportedFrameworks(
+    __in LPCWSTR wzConfigPath
+    );
+static HRESULT UpdateSupportedRuntime(
+    __in IXMLDOMDocument* pixdManifest,
+    __in IXMLDOMNode* pixnSupportedFramework,
+    __out BOOL* pfUpdatedManifest
+    );
+static HRESULT GetCLRHost(
+    __in LPCWSTR wzConfigPath,
+    __out ICorRuntimeHost** ppCLRHost
+    );
+static HRESULT CreateManagedBootstrapperApplication(
+    __in _AppDomain* pAppDomain,
+    __in IBootstrapperEngine* pEngine,
+    __in const BOOTSTRAPPER_CREATE_ARGS* pArgs,
+    __inout BOOTSTRAPPER_CREATE_RESULTS* pResults
+    );
+static HRESULT CreateManagedBootstrapperApplicationFactory(
+    __in _AppDomain* pAppDomain,
+    __out IBootstrapperApplicationFactory** ppAppFactory
+    );
+static HRESULT CreatePrerequisiteBA(
+    __in HRESULT hrHostInitialization,
+    __in IBootstrapperEngine* pEngine,
+    __in const BOOTSTRAPPER_CREATE_ARGS* pArgs,
+    __inout BOOTSTRAPPER_CREATE_RESULTS* pResults
+    );
+static HRESULT VerifyNET4RuntimeIsSupported(
+    );
+
+
+// function definitions
+
+extern "C" BOOL WINAPI DllMain(
+    IN HINSTANCE hInstance,
+    IN DWORD dwReason,
+    IN LPVOID /* pvReserved */
+    )
+{
+    switch (dwReason)
+    {
+    case DLL_PROCESS_ATTACH:
+        ::DisableThreadLibraryCalls(hInstance);
+        vhInstance = hInstance;
+        break;
+
+    case DLL_PROCESS_DETACH:
+        vhInstance = NULL;
+        break;
+    }
+
+    return TRUE;
+}
+
+// Note: This function assumes that COM was already initialized on the thread.
+extern "C" HRESULT WINAPI BootstrapperApplicationCreate(
+    __in const BOOTSTRAPPER_CREATE_ARGS* pArgs,
+    __inout BOOTSTRAPPER_CREATE_RESULTS* pResults
+    )
+{
+    HRESULT hr = S_OK; 
+    HRESULT hrHostInitialization = S_OK;
+    IBootstrapperEngine* pEngine = NULL;
+
+    hr = BalInitializeFromCreateArgs(pArgs, &pEngine);
+    ExitOnFailure(hr, "Failed to initialize Bal.");
+
+    hr = GetAppDomain(&vpAppDomain);
+    if (SUCCEEDED(hr))
+    {
+        BalLog(BOOTSTRAPPER_LOG_LEVEL_STANDARD, "Loading managed bootstrapper application.");
+
+        hr = CreateManagedBootstrapperApplication(vpAppDomain, pEngine, pArgs, pResults);
+        BalExitOnFailure(hr, "Failed to create the managed bootstrapper application.");
+    }
+    else // fallback to the prerequisite BA.
+    {
+        if (E_MBAHOST_NET452_ON_WIN7RTM == hr)
+        {
+            BalLogError(hr, "The Burn engine cannot run with an MBA under the .NET 4 CLR on Windows 7 RTM with .NET 4.5.2 (or greater) installed.");
+            hrHostInitialization = hr;
+        }
+        else
+        {
+            hrHostInitialization = S_OK;
+        }
+
+        BalLog(BOOTSTRAPPER_LOG_LEVEL_STANDARD, "Loading prerequisite bootstrapper application because managed host could not be loaded, error: 0x%08x.", hr);
+
+        hr = CreatePrerequisiteBA(hrHostInitialization, pEngine, pArgs, pResults);
+        BalExitOnFailure(hr, "Failed to create the pre-requisite bootstrapper application.");
+    }
+
+LExit:
+    return hr;
+}
+
+extern "C" void WINAPI BootstrapperApplicationDestroy()
+{
+    if (vpAppDomain)
+    {
+        HRESULT hr = vpCLRHost->UnloadDomain(vpAppDomain);
+        if (FAILED(hr))
+        {
+            BalLogError(hr, "Failed to unload app domain.");
+        }
+
+        vpAppDomain->Release();
+    }
+
+    if (vpCLRHost)
+    {
+        vpCLRHost->Stop();
+        vpCLRHost->Release();
+    }
+
+    if (vhMbapreqModule)
+    {
+        PFN_BOOTSTRAPPER_APPLICATION_DESTROY pfnDestroy = reinterpret_cast<PFN_BOOTSTRAPPER_APPLICATION_DESTROY>(::GetProcAddress(vhMbapreqModule, "MbaPrereqBootstrapperApplicationDestroy"));
+        if (pfnDestroy)
+        {
+            (*pfnDestroy)();
+        }
+
+        ::FreeLibrary(vhMbapreqModule);
+        vhMbapreqModule = NULL;
+    }
+
+    BalUninitialize();
+}
+
+// Gets the custom AppDomain for loading managed BA.
+static HRESULT GetAppDomain(
+    __out _AppDomain **ppAppDomain
+    )
+{
+    HRESULT hr = S_OK;
+    ICorRuntimeHost *pCLRHost = NULL;
+    IUnknown *pUnk = NULL;
+    LPWSTR sczAppBase = NULL;
+    LPWSTR sczConfigPath = NULL;
+    IAppDomainSetup *pAppDomainSetup;
+    BSTR bstrAppBase = NULL;
+    BSTR bstrConfigPath = NULL;
+
+    hr = GetAppBase(&sczAppBase);
+    ExitOnFailure(hr, "Failed to get the host base path.");
+
+    hr = PathConcat(sczAppBase, L"BootstrapperCore.config", &sczConfigPath);
+    ExitOnFailure(hr, "Failed to get the full path to the application configuration file.");
+
+    // Check that the supported framework is installed.
+    hr = CheckSupportedFrameworks(sczConfigPath);
+    ExitOnFailure(hr, "Failed to find supported framework.");
+
+    // Load the CLR.
+    hr = GetCLRHost(sczConfigPath, &pCLRHost);
+    ExitOnFailure(hr, "Failed to create the CLR host.");
+
+    hr = pCLRHost->Start();
+    ExitOnRootFailure(hr, "Failed to start the CLR host.");
+
+    // Create the setup information for a new AppDomain to set the app base and config.
+    hr = pCLRHost->CreateDomainSetup(&pUnk);
+    ExitOnRootFailure(hr, "Failed to create the AppDomainSetup object.");
+
+    hr = pUnk->QueryInterface(__uuidof(IAppDomainSetup), reinterpret_cast<LPVOID*>(&pAppDomainSetup));
+    ExitOnRootFailure(hr, "Failed to query for the IAppDomainSetup interface.");
+    ReleaseNullObject(pUnk);
+
+    // Set properties on the AppDomainSetup object.
+    bstrAppBase = ::SysAllocString(sczAppBase);
+    ExitOnNull(bstrAppBase, hr, E_OUTOFMEMORY, "Failed to allocate the application base path for the AppDomainSetup.");
+
+    hr = pAppDomainSetup->put_ApplicationBase(bstrAppBase);
+    ExitOnRootFailure(hr, "Failed to set the application base path for the AppDomainSetup.");
+
+    bstrConfigPath = ::SysAllocString(sczConfigPath);
+    ExitOnNull(bstrConfigPath, hr, E_OUTOFMEMORY, "Failed to allocate the application configuration file for the AppDomainSetup.");
+
+    hr = pAppDomainSetup->put_ConfigurationFile(bstrConfigPath);
+    ExitOnRootFailure(hr, "Failed to set the configuration file path for the AppDomainSetup.");
+
+    // Create the AppDomain to load the factory type.
+    hr = pCLRHost->CreateDomainEx(L"MBA", pAppDomainSetup, NULL, &pUnk);
+    ExitOnRootFailure(hr, "Failed to create the MBA AppDomain.");
+
+    hr = pUnk->QueryInterface(__uuidof(_AppDomain), reinterpret_cast<LPVOID*>(ppAppDomain));
+    ExitOnRootFailure(hr, "Failed to query for the _AppDomain interface.");
+
+LExit:
+    ReleaseBSTR(bstrConfigPath);
+    ReleaseBSTR(bstrAppBase);
+    ReleaseStr(sczConfigPath);
+    ReleaseStr(sczAppBase);
+    ReleaseNullObject(pUnk);
+    ReleaseNullObject(pCLRHost);
+
+    return hr;
+}
+
+static HRESULT GetAppBase(
+    __out LPWSTR *psczAppBase
+    )
+{
+    HRESULT hr = S_OK;
+    LPWSTR sczFullPath = NULL;
+
+    hr = PathForCurrentProcess(&sczFullPath, vhInstance);
+    ExitOnFailure(hr, "Failed to get the full host path.");
+
+    hr = PathGetDirectory(sczFullPath, psczAppBase);
+    ExitOnFailure(hr, "Failed to get the directory of the full process path.");
+
+LExit:
+    ReleaseStr(sczFullPath);
+
+    return hr;
+}
+
+// Checks whether at least one of required supported frameworks is installed via the NETFX registry keys.
+static HRESULT CheckSupportedFrameworks(
+    __in LPCWSTR wzConfigPath
+    )
+{
+    HRESULT hr = S_OK;
+    IXMLDOMDocument* pixdManifest = NULL;
+    IXMLDOMNodeList* pNodeList = NULL;
+    IXMLDOMNode* pNode = NULL;
+    DWORD cSupportedFrameworks = 0;
+    LPWSTR sczSupportedFrameworkVersion = NULL;
+    LPWSTR sczFrameworkRegistryKey = NULL;
+    HKEY hkFramework = NULL;
+    DWORD dwFrameworkInstalled = 0;
+    BOOL fUpdatedManifest = FALSE;
+
+    hr = XmlInitialize();
+    ExitOnFailure(hr, "Failed to initialize XML.");
+
+    hr = XmlLoadDocumentFromFile(wzConfigPath, &pixdManifest);
+    ExitOnFailure(hr, "Failed to load bootstrapper config file from path: %ls", wzConfigPath);
+
+    hr = XmlSelectNodes(pixdManifest, L"/configuration/wix.bootstrapper/host/supportedFramework", &pNodeList);
+    ExitOnFailure(hr, "Failed to select all supportedFramework elements.");
+
+    hr = pNodeList->get_length(reinterpret_cast<long*>(&cSupportedFrameworks));
+    ExitOnFailure(hr, "Failed to get the supported framework count.");
+
+    if (cSupportedFrameworks)
+    {
+        while (S_OK == (hr = XmlNextElement(pNodeList, &pNode, NULL)))
+        {
+            hr = XmlGetAttributeEx(pNode, L"version", &sczSupportedFrameworkVersion);
+            ExitOnFailure(hr, "Failed to get supportedFramework/@version.");
+
+            hr = StrAllocFormatted(&sczFrameworkRegistryKey, L"SOFTWARE\\Microsoft\\NET Framework Setup\\NDP\\%ls", sczSupportedFrameworkVersion);
+            ExitOnFailure(hr, "Failed to allocate path to supported framework Install registry key.");
+
+            hr = RegOpen(HKEY_LOCAL_MACHINE, sczFrameworkRegistryKey, KEY_READ, &hkFramework);
+            if (SUCCEEDED(hr))
+            {
+                hr = RegReadNumber(hkFramework, L"Install", &dwFrameworkInstalled);
+                if (dwFrameworkInstalled)
+                {
+                    hr = S_OK;
+                    break;
+                }
+            }
+
+            ReleaseNullObject(pNode);
+        }
+
+        // If we looped through all the supported frameworks but didn't find anything, ensure we return a failure.
+        if (S_FALSE == hr)
+        {
+            hr = E_NOTFOUND;
+            ExitOnRootFailure(hr, "Failed to find a supported framework.");
+        }
+
+        hr = UpdateSupportedRuntime(pixdManifest, pNode, &fUpdatedManifest);
+        ExitOnFailure(hr, "Failed to update supportedRuntime.");
+    }
+    // else no supported frameworks specified, so the startup/supportedRuntime must be enough.
+
+    if (fUpdatedManifest)
+    {
+        hr = XmlSaveDocument(pixdManifest, wzConfigPath);
+        ExitOnFailure(hr, "Failed to save updated manifest over config file: %ls", wzConfigPath);
+    }
+
+LExit:
+    ReleaseRegKey(hkFramework);
+    ReleaseStr(sczFrameworkRegistryKey);
+    ReleaseStr(sczSupportedFrameworkVersion);
+    ReleaseObject(pNode);
+    ReleaseObject(pNodeList);
+    ReleaseObject(pixdManifest);
+
+    XmlUninitialize();
+
+    return hr;
+}
+
+// Fixes the supportedRuntime element if necessary.
+static HRESULT UpdateSupportedRuntime(
+    __in IXMLDOMDocument* pixdManifest,
+    __in IXMLDOMNode* pixnSupportedFramework,
+    __out BOOL* pfUpdatedManifest
+    )
+{
+    HRESULT hr = S_OK;
+    LPWSTR sczSupportedRuntimeVersion = NULL;
+    IXMLDOMNode* pixnStartup = NULL;
+    IXMLDOMNode* pixnSupportedRuntime = NULL;
+
+    *pfUpdatedManifest = FALSE;
+
+    // If the runtime version attribute is not specified, don't update the manifest.
+    hr = XmlGetAttributeEx(pixnSupportedFramework, L"runtimeVersion", &sczSupportedRuntimeVersion);
+    if (E_NOTFOUND == hr)
+    {
+        ExitFunction1(hr = S_OK);
+    }
+    ExitOnFailure(hr, "Failed to get supportedFramework/@runtimeVersion.");
+
+    // Get the startup element. Fail if we can't find it since it'll be necessary to load the
+    // correct runtime.
+    hr = XmlSelectSingleNode(pixdManifest, L"/configuration/startup", &pixnStartup);
+    ExitOnFailure(hr, "Failed to get startup element.");
+
+    if (S_FALSE == hr)
+    {
+        hr = E_NOTFOUND;
+        ExitOnRootFailure(hr, "Failed to find startup element in bootstrapper application config.");
+    }
+
+    // Remove any pre-existing supported runtimes because they'll just get in the way and create our new one.
+    hr = XmlRemoveChildren(pixnStartup, L"supportedRuntime");
+    ExitOnFailure(hr, "Failed to remove pre-existing supportedRuntime elements.");
+
+    hr = XmlCreateChild(pixnStartup, L"supportedRuntime", &pixnSupportedRuntime);
+    ExitOnFailure(hr, "Failed to create supportedRuntime element.");
+
+    hr = XmlSetAttribute(pixnSupportedRuntime, L"version", sczSupportedRuntimeVersion);
+    ExitOnFailure(hr, "Failed to set supportedRuntime/@version to '%ls'.", sczSupportedRuntimeVersion);
+
+    *pfUpdatedManifest = TRUE;
+
+LExit:
+    ReleaseObject(pixnSupportedRuntime);
+    ReleaseObject(pixnStartup);
+    ReleaseStr(sczSupportedRuntimeVersion);
+
+    return hr;
+}
+
+// Gets the CLR host and caches it.
+static HRESULT GetCLRHost(
+    __in LPCWSTR wzConfigPath,
+    __out ICorRuntimeHost **ppCLRHost
+    )
+{
+    HRESULT hr = S_OK;
+    UINT uiMode = 0;
+    HMODULE hModule = NULL;
+    BOOL fFallbackToCorBindToCurrentRuntime = TRUE;
+    CLRCreateInstanceFnPtr pfnCLRCreateInstance = NULL;
+    ICLRMetaHostPolicy* pCLRMetaHostPolicy = NULL;
+    IStream* pCfgStream = NULL;
+    LPWSTR pwzVersion = NULL;
+    DWORD cchVersion = 0;
+    DWORD dwConfigFlags = 0;
+    ICLRRuntimeInfo* pCLRRuntimeInfo = NULL;
+    PFN_CORBINDTOCURRENTRUNTIME pfnCorBindToCurrentRuntime = NULL;
+
+    // Always set the error mode because we will always restore it below.
+    uiMode = ::SetErrorMode(0);
+
+    // Cache the CLR host to be shutdown later. This can occur on a different thread.
+    if (!vpCLRHost)
+    {
+        // Disable message boxes from being displayed on error and blocking execution.
+        ::SetErrorMode(uiMode | SEM_FAILCRITICALERRORS);
+
+        hr = LoadSystemLibrary(L"mscoree.dll", &hModule);
+        ExitOnFailure(hr, "Failed to load mscoree.dll");
+
+        pfnCLRCreateInstance = reinterpret_cast<CLRCreateInstanceFnPtr>(::GetProcAddress(hModule, "CLRCreateInstance"));
+        
+        if (pfnCLRCreateInstance)
+        {
+            hr = pfnCLRCreateInstance(CLSID_CLRMetaHostPolicy, IID_ICLRMetaHostPolicy, reinterpret_cast<LPVOID*>(&pCLRMetaHostPolicy));
+            if (E_NOTIMPL != hr)
+            {
+                ExitOnRootFailure(hr, "Failed to create instance of ICLRMetaHostPolicy.");
+
+                fFallbackToCorBindToCurrentRuntime = FALSE;
+            }
+        }
+
+        if (fFallbackToCorBindToCurrentRuntime)
+        {
+            pfnCorBindToCurrentRuntime = reinterpret_cast<PFN_CORBINDTOCURRENTRUNTIME>(::GetProcAddress(hModule, "CorBindToCurrentRuntime"));
+            ExitOnNullWithLastError(pfnCorBindToCurrentRuntime, hr, "Failed to get procedure address for CorBindToCurrentRuntime.");
+
+            hr = pfnCorBindToCurrentRuntime(wzConfigPath, CLSID_CorRuntimeHost, IID_ICorRuntimeHost, reinterpret_cast<LPVOID*>(&vpCLRHost));
+            ExitOnRootFailure(hr, "Failed to create the CLR host using the application configuration file path.");
+        }
+        else
+        {
+
+            hr = SHCreateStreamOnFileEx(wzConfigPath, STGM_READ | STGM_SHARE_DENY_WRITE, 0, FALSE, NULL, &pCfgStream);
+            ExitOnFailure(hr, "Failed to load bootstrapper config file from path: %ls", wzConfigPath);
+
+            hr = pCLRMetaHostPolicy->GetRequestedRuntime(METAHOST_POLICY_HIGHCOMPAT, NULL, pCfgStream, NULL, &cchVersion, NULL, NULL, &dwConfigFlags, IID_ICLRRuntimeInfo, reinterpret_cast<LPVOID*>(&pCLRRuntimeInfo));
+            ExitOnRootFailure(hr, "Failed to get the CLR runtime info using the application configuration file path.");
+
+            // .NET 4 RTM had a bug where it wouldn't set pcchVersion if pwzVersion was NULL.
+            if (!cchVersion)
+            {
+                hr = pCLRRuntimeInfo->GetVersionString(NULL, &cchVersion);
+                if (HRESULT_FROM_WIN32(ERROR_INSUFFICIENT_BUFFER) != hr)
+                {
+                    ExitOnFailure(hr, "Failed to get the length of the CLR version string.");
+                }
+            }
+
+            hr = StrAlloc(&pwzVersion, cchVersion);
+            ExitOnFailure(hr, "Failed to allocate the CLR version string.");
+
+            hr = pCLRRuntimeInfo->GetVersionString(pwzVersion, &cchVersion);
+            ExitOnFailure(hr, "Failed to get the CLR version string.");
+
+            if (CSTR_EQUAL == CompareString(LOCALE_NEUTRAL, 0, L"v4.0.30319", -1, pwzVersion, cchVersion))
+            {
+                hr = VerifyNET4RuntimeIsSupported();
+                ExitOnFailure(hr, "Found unsupported .NET 4 Runtime.");
+            }
+
+            if (METAHOST_CONFIG_FLAGS_LEGACY_V2_ACTIVATION_POLICY_TRUE == (METAHOST_CONFIG_FLAGS_LEGACY_V2_ACTIVATION_POLICY_MASK & dwConfigFlags))
+            {
+                hr = pCLRRuntimeInfo->BindAsLegacyV2Runtime();
+                ExitOnRootFailure(hr, "Failed to bind as legacy V2 runtime.");
+            }
+
+            hr = pCLRRuntimeInfo->GetInterface(CLSID_CorRuntimeHost, IID_ICorRuntimeHost, reinterpret_cast<LPVOID*>(&vpCLRHost));
+            ExitOnRootFailure(hr, "Failed to get instance of ICorRuntimeHost.");
+
+            // TODO: use ICLRRuntimeHost instead of ICorRuntimeHost on .NET 4 since the former is faster and the latter is deprecated
+            //hr = pCLRRuntimeInfo->GetInterface(CLSID_CLRRuntimeHost, IID_ICLRRuntimeHost, reinterpret_cast<LPVOID*>(&pCLRRuntimeHost));
+            //ExitOnRootFailure(hr, "Failed to get instance of ICLRRuntimeHost.");
+        }
+    }
+
+    vpCLRHost->AddRef();
+    *ppCLRHost = vpCLRHost;
+
+LExit:
+    ReleaseStr(pwzVersion);
+    ReleaseNullObject(pCLRRuntimeInfo);
+    ReleaseNullObject(pCfgStream);
+    ReleaseNullObject(pCLRMetaHostPolicy);
+
+    // Unload the module so it's not in use when we install .NET.
+    if (FAILED(hr))
+    {
+        ::FreeLibrary(hModule);
+    }
+
+    ::SetErrorMode(uiMode); // restore the previous error mode.
+
+    return hr;
+}
+
+// Creates the bootstrapper app and returns it for the engine.
+static HRESULT CreateManagedBootstrapperApplication(
+    __in _AppDomain* pAppDomain,
+    __in IBootstrapperEngine* pEngine,
+    __in const BOOTSTRAPPER_CREATE_ARGS* pArgs,
+    __inout BOOTSTRAPPER_CREATE_RESULTS* pResults
+    )
+{
+    HRESULT hr = S_OK;
+    IBootstrapperApplicationFactory* pAppFactory = NULL;
+    IBootstrapperApplication* pApp = NULL;
+
+    hr = CreateManagedBootstrapperApplicationFactory(pAppDomain, &pAppFactory);
+    ExitOnFailure(hr, "Failed to create the factory to create the bootstrapper application.");
+
+    hr = pAppFactory->Create(pEngine, pArgs->pCommand, &pApp);
+    ExitOnFailure(hr, "Failed to create the bootstrapper application.");
+
+    pResults->pfnBootstrapperApplicationProc = BalBaseBootstrapperApplicationProc;
+    pResults->pvBootstrapperApplicationProcContext = pApp;
+    pApp = NULL;
+
+LExit:
+    ReleaseNullObject(pApp);
+    ReleaseNullObject(pAppFactory);
+
+    return hr;
+}
+
+// Creates the app factory to create the managed app in the default AppDomain.
+static HRESULT CreateManagedBootstrapperApplicationFactory(
+    __in _AppDomain* pAppDomain,
+    __out IBootstrapperApplicationFactory** ppAppFactory
+    )
+{
+    HRESULT hr = S_OK;
+    BSTR bstrAssemblyName = NULL;
+    BSTR bstrTypeName = NULL;
+    _ObjectHandle* pObj = NULL;
+    VARIANT vtBAFactory;
+
+    ::VariantInit(&vtBAFactory);
+
+    bstrAssemblyName = ::SysAllocString(MUX_ASSEMBLY_FULL_NAME);
+    ExitOnNull(bstrAssemblyName, hr, E_OUTOFMEMORY, "Failed to allocate the full assembly name for the bootstrapper application factory.");
+
+    bstrTypeName = ::SysAllocString(L"WixToolset.Bootstrapper.BootstrapperApplicationFactory");
+    ExitOnNull(bstrTypeName, hr, E_OUTOFMEMORY, "Failed to allocate the full type name for the BA factory.");
+
+    hr = pAppDomain->CreateInstance(bstrAssemblyName, bstrTypeName, &pObj);
+    ExitOnRootFailure(hr, "Failed to create the BA factory object.");
+
+    hr = pObj->Unwrap(&vtBAFactory);
+    ExitOnRootFailure(hr, "Failed to unwrap the BA factory object into the host domain.");
+    ExitOnNull(vtBAFactory.punkVal, hr, E_UNEXPECTED, "The variant did not contain the expected IUnknown pointer.");
+
+    hr = vtBAFactory.punkVal->QueryInterface(__uuidof(IBootstrapperApplicationFactory), reinterpret_cast<LPVOID*>(ppAppFactory));
+    ExitOnRootFailure(hr, "Failed to query for the bootstrapper app factory interface.");
+
+LExit:
+    ReleaseVariant(vtBAFactory);
+    ReleaseNullObject(pObj);
+    ReleaseBSTR(bstrTypeName);
+    ReleaseBSTR(bstrAssemblyName);
+
+    return hr;
+}
+
+static HRESULT CreatePrerequisiteBA(
+    __in HRESULT hrHostInitialization,
+    __in IBootstrapperEngine* pEngine,
+    __in const BOOTSTRAPPER_CREATE_ARGS* pArgs,
+    __inout BOOTSTRAPPER_CREATE_RESULTS* pResults
+    )
+{
+    HRESULT hr = S_OK;
+    LPWSTR sczMbapreqPath = NULL;
+    HMODULE hModule = NULL;
+
+    hr = PathRelativeToModule(&sczMbapreqPath, L"mbapreq.dll", vhInstance);
+    ExitOnFailure(hr, "Failed to get path to pre-requisite BA.");
+
+    hModule = ::LoadLibraryW(sczMbapreqPath);
+    ExitOnNullWithLastError(hModule, hr, "Failed to load pre-requisite BA DLL.");
+
+    PFN_MBAPREQ_BOOTSTRAPPER_APPLICATION_CREATE pfnCreate = reinterpret_cast<PFN_MBAPREQ_BOOTSTRAPPER_APPLICATION_CREATE>(::GetProcAddress(hModule, "MbaPrereqBootstrapperApplicationCreate"));
+    ExitOnNullWithLastError(pfnCreate, hr, "Failed to get MbaPrereqBootstrapperApplicationCreate entry-point from: %ls", sczMbapreqPath);
+
+    hr = pfnCreate(hrHostInitialization, pEngine, pArgs, pResults);
+    ExitOnFailure(hr, "Failed to create prequisite bootstrapper app.");
+
+    vhMbapreqModule = hModule;
+    hModule = NULL;
+
+LExit:
+    if (hModule)
+    {
+        ::FreeLibrary(hModule);
+    }
+    ReleaseStr(sczMbapreqPath);
+
+    return hr;
+}
+
+static HRESULT VerifyNET4RuntimeIsSupported(
+    )
+{
+    HRESULT hr = S_OK;
+    OS_VERSION osv = OS_VERSION_UNKNOWN;
+    DWORD dwServicePack = 0;
+    HKEY hKey = NULL;
+    DWORD er = ERROR_SUCCESS;
+    DWORD dwRelease = 0;
+    DWORD cchRelease = sizeof(dwRelease);
+
+    OsGetVersion(&osv, &dwServicePack);
+    if (OS_VERSION_WIN7 == osv && 0 == dwServicePack)
+    {
+        hr = RegOpen(HKEY_LOCAL_MACHINE, L"SOFTWARE\\Microsoft\\NET Framework Setup\\NDP\\v4\\Full", KEY_QUERY_VALUE, &hKey);
+        if (E_FILENOTFOUND == hr)
+        {
+            ExitFunction1(hr = S_OK);
+        }
+        ExitOnFailure(hr, "Failed to open registry key for .NET 4.");
+
+        er = ::RegQueryValueExW(hKey, L"Release", NULL, NULL, reinterpret_cast<LPBYTE>(&dwRelease), &cchRelease);
+        if (ERROR_FILE_NOT_FOUND == er)
+        {
+            ExitFunction1(hr = S_OK);
+        }
+        ExitOnWin32Error(er, hr, "Failed to get Release value.");
+
+        if (NET452_RELEASE <= dwRelease)
+        {
+            hr = E_MBAHOST_NET452_ON_WIN7RTM;
+        }
+    }
+
+LExit:
+    ReleaseRegKey(hKey);
+
+    return hr;
+}
diff --git a/src/mbahost/host.def b/src/mbahost/host.def
new file mode 100644
index 00000000..4488df94
--- /dev/null
+++ b/src/mbahost/host.def
@@ -0,0 +1,6 @@
+; Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+
+EXPORTS
+    BootstrapperApplicationCreate
+    BootstrapperApplicationDestroy
diff --git a/src/mbahost/host.vcxproj b/src/mbahost/host.vcxproj
new file mode 100644
index 00000000..a4c3ea16
--- /dev/null
+++ b/src/mbahost/host.vcxproj
@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. -->
+
+
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{12C87C77-3547-44F8-8134-29BC915CB19D}</ProjectGuid>
+    <ConfigurationType>DynamicLibrary</ConfigurationType>
+    <CharacterSet>Unicode</CharacterSet>
+    <TargetName>mbahost</TargetName>
+    <ProjectModuleDefinitionFile>host.def</ProjectModuleDefinitionFile>
+  </PropertyGroup>
+
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildProjectDirectory), wix.proj))\tools\WixBuild.props" />
+
+  <PropertyGroup>
+    <ProjectAdditionalIncludeDirectories>$(WixRoot)src\libs\dutil\inc;$(WixRoot)src\burn\inc;$(WixRoot)src\libs\balutil\inc;$(BaseIntermediateOutputPath)\core</ProjectAdditionalIncludeDirectories>
+    <ProjectAdditionalLinkLibraries>dutil.lib;balutil.lib;shlwapi.lib</ProjectAdditionalLinkLibraries>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ClCompile Include="host.cpp" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="IBootstrapperApplicationFactory.h" />
+    <ClInclude Include="precomp.h" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="host.def" />
+  </ItemGroup>
+  <ItemGroup>
+    <ResourceCompile Include="host.rc" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\core\core.csproj" />
+  </ItemGroup>
+
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildProjectDirectory), wix.proj))\tools\WixBuild.targets" />
+</Project>
diff --git a/src/mbahost/precomp.h b/src/mbahost/precomp.h
new file mode 100644
index 00000000..d29a23f3
--- /dev/null
+++ b/src/mbahost/precomp.h
@@ -0,0 +1,25 @@
+#pragma once
+// Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information.
+
+
+#include <windows.h>
+#include <msiquery.h>
+#include <metahost.h>
+#include <shlwapi.h>
+
+#import <mscorlib.tlb> raw_interfaces_only rename("ReportEvent", "mscorlib_ReportEvent")
+
+#include <dutil.h>
+#include <osutil.h>
+#include <pathutil.h>
+#include <regutil.h>
+#include <strutil.h>
+#include <xmlutil.h>
+
+#include "BootstrapperEngine.h"
+#include "BootstrapperApplication.h"
+#include "IBootstrapperEngine.h"
+#include "IBootstrapperApplication.h"
+#include "IBootstrapperApplicationFactory.h"
+
+#include "balutil.h"