diff --git a/.azure-pipelines/build-template.yml b/.azure-pipelines/build-template.yml
index 6cd6a7a699..40f85237d6 100644
--- a/.azure-pipelines/build-template.yml
+++ b/.azure-pipelines/build-template.yml
@@ -23,6 +23,12 @@ parameters:
 - name: sonic_slave
   type: string
 
+- name: buildimage_artifact_name
+  type: string
+
+- name: buildimage_pipeline
+  type: number
+
 - name: sairedis_artifact_name
   type: string
 
@@ -36,6 +42,10 @@ parameters:
   type: boolean
   default: false
 
+- name: archive_gcov
+  type: boolean
+  default: false
+
 jobs:
 - job:
   displayName: ${{ parameters.arch }}
@@ -51,26 +61,28 @@ jobs:
     image: sonicdev-microsoft.azurecr.io:443/${{ parameters.sonic_slave }}:latest
 
   steps:
+  - checkout: self
+    clean: true
+    submodules: true
+  - script: |
+      sourceBranch=$(Build.SourceBranchName)
+      if [[ "$(Build.Reason)" == "PullRequest" ]];then
+        sourceBranch=$(System.PullRequest.TargetBranch)
+      fi
+      echo "Download artifact branch: $sourceBranch"
+      echo "##vso[task.setvariable variable=sourceBranch]$sourceBranch"
+    displayName: "Get correct artifact downloading branch"
   - script: |
       sudo apt-get install -y libhiredis0.14 libhiredis-dev
       sudo apt-get install -y libzmq5 libzmq3-dev
       sudo apt-get install -qq -y \
           libhiredis-dev \
-          libnl-3-dev \
-          libnl-genl-3-dev \
-          libnl-route-3-dev \
-          libnl-nf-3-dev \
           swig3.0
       sudo apt-get install -y libdbus-1-3
       sudo apt-get install -y libteam-dev \
           libteam5 \
           libteamdctl0
     displayName: "Install dependencies"
-  - script: |
-      ls -al $(Pipeline.Workspace)
-      rm -rf $(Pipeline.Workspace)/*.deb
-      ls -al $(Pipeline.Workspace)
-    displayName: "Clean workspace"
   - task: DownloadPipelineArtifact@2
     inputs:
       source: specific
@@ -78,7 +90,12 @@ jobs:
       pipeline: 9
       artifact: ${{ parameters.swss_common_artifact_name }}
       runVersion: 'latestFromBranch'
-      runBranch: 'refs/heads/master'
+      runBranch: 'refs/heads/$(sourceBranch)'
+      path: '$(Build.SourcesDirectory)/${{ parameters.swss_common_artifact_name }}'
+      allowFailedBuilds: true
+      patterns: |
+        **/libswsscommon_1.0.0_${{ parameters.arch }}.deb
+        **/libswsscommon-dev_1.0.0_${{ parameters.arch }}.deb
     displayName: "Download sonic swss common deb packages"
   - task: DownloadPipelineArtifact@2
     inputs:
@@ -87,26 +104,50 @@ jobs:
       pipeline: 12
       artifact: ${{ parameters.sairedis_artifact_name }}
       runVersion: 'latestFromBranch'
-      runBranch: 'refs/heads/master'
+      runBranch: 'refs/heads/$(sourceBranch)'
+      path: '$(Build.SourcesDirectory)/${{ parameters.sairedis_artifact_name }}'
+      allowFailedBuilds: true
+      patterns: |
+        **/libsaivs_*.deb
+        **/libsaivs-dev_*.deb
+        **/libsairedis_*.deb
+        **/libsairedis-dev_*.deb
+        **/libsaimetadata_*.deb
+        **/libsaimetadata-dev_*.deb
+        **/syncd-vs_*.deb
     displayName: "Download sonic sairedis deb packages"
+  - task: DownloadPipelineArtifact@2
+    inputs:
+      source: specific
+      project: build
+      pipeline: ${{ parameters.buildimage_pipeline }}
+      runVersion: 'latestFromBranch'
+      runBranch: 'refs/heads/$(sourceBranch)'
+      path: '$(Build.SourcesDirectory)/${{ parameters.buildimage_artifact_name }}'
+      allowFailedBuilds: true
+      patterns: |
+        **/target/debs/**/libnl-3-200_*.deb
+        **/target/debs/**/libnl-3-dev_*.deb
+        **/target/debs/**/libnl-genl-3-200_*.deb
+        **/target/debs/**/libnl-genl-3-dev_*.deb
+        **/target/debs/**/libnl-route-3-200_*.deb
+        **/target/debs/**/libnl-route-3-dev_*.deb
+        **/target/debs/**/libnl-nf-3-200_*.deb
+        **/target/debs/**/libnl-nf-3-dev_*.deb
+    displayName: "Download sonic buildimage deb packages"
   - script: |
-      sudo dpkg -i libswsscommon_1.0.0_${{ parameters.arch }}.deb
-      sudo dpkg -i libswsscommon-dev_1.0.0_${{ parameters.arch }}.deb
-      sudo dpkg -i libsaivs_*.deb
-      sudo dpkg -i libsaivs-dev_*.deb
-      sudo dpkg -i libsairedis_*.deb
-      sudo dpkg -i libsairedis-dev_*.deb
-      sudo dpkg -i libsaimetadata_*.deb
-      sudo dpkg -i libsaimetadata-dev_*.deb
-      sudo dpkg -i syncd-vs_*.deb
-    workingDirectory: $(Pipeline.Workspace)
-    displayName: "Install sonic swss common and sairedis"
-  - checkout: self
-    submodules: true
+      set -ex
+      sudo dpkg -i $(find ${{ parameters.buildimage_artifact_name }} -name "*.deb")
+      sudo dpkg -i $(find ${{ parameters.swss_common_artifact_name }} -name "*.deb")
+      sudo dpkg -i $(find ${{ parameters.sairedis_artifact_name }} -name "*.deb")
+    displayName: "Install libnl3, sonic swss common and sairedis"
   - script: |
-      set -x
+      set -ex
       tar czf pytest.tgz tests
       cp -r pytest.tgz $(Build.ArtifactStagingDirectory)/
+      if [ '${{ parameters.archive_gcov }}' == True ]; then
+         export ENABLE_GCOV=y
+      fi
       ./autogen.sh
       dpkg-buildpackage -us -uc -b -j$(nproc) && cp ../*.deb .
     displayName: "Compile sonic swss"
diff --git a/.azure-pipelines/docker-sonic-vs/Dockerfile b/.azure-pipelines/docker-sonic-vs/Dockerfile
index d425a6ffea..f288c8fdaa 100644
--- a/.azure-pipelines/docker-sonic-vs/Dockerfile
+++ b/.azure-pipelines/docker-sonic-vs/Dockerfile
@@ -4,6 +4,15 @@ ARG docker_container_name
 
 ADD ["debs", "/debs"]
 
+RUN dpkg --purge python-swsscommon
+RUN dpkg --purge python3-swsscommon
+RUN dpkg --purge swss
+RUN dpkg --purge libsairedis
+RUN dpkg --purge libswsscommon
+RUN dpkg --purge libsaimetadata
+RUN dpkg --purge libsaivs
+RUN dpkg --purge syncd-vs
+
 RUN dpkg -i /debs/libswsscommon_1.0.0_amd64.deb
 RUN dpkg -i /debs/python-swsscommon_1.0.0_amd64.deb
 RUN dpkg -i /debs/python3-swsscommon_1.0.0_amd64.deb
@@ -15,3 +24,7 @@ RUN dpkg -i /debs/syncd-vs_1.0.0_amd64.deb
 
 RUN dpkg --purge swss
 RUN dpkg -i /debs/swss_1.0.0_amd64.deb
+
+RUN apt-get update
+
+RUN apt-get -y install lcov
diff --git a/.azure-pipelines/gcov.yml b/.azure-pipelines/gcov.yml
new file mode 100644
index 0000000000..0940f82cce
--- /dev/null
+++ b/.azure-pipelines/gcov.yml
@@ -0,0 +1,129 @@
+parameters:
+- name: arch
+  type: string
+  values:
+  - amd64
+  default: amd64
+
+- name: pool
+  type: string
+  values:
+  - sonicbld
+  - default
+  default: default
+
+- name: timeout
+  type: number
+  default: 180
+
+- name: sonic_slave
+  type: string
+
+- name: sairedis_artifact_name
+  type: string
+
+- name: swss_common_artifact_name
+  type: string
+
+- name: swss_artifact_name
+  type: string
+
+- name: artifact_name
+  type: string
+
+- name: archive_gcov
+  type: boolean
+  default: false
+
+jobs:
+- job:
+  displayName: ${{ parameters.arch }}
+  timeoutInMinutes: ${{ parameters.timeout }}
+
+  pool:
+    ${{ if ne(parameters.pool, 'default') }}:
+      name: ${{ parameters.pool }}
+    ${{ if eq(parameters.pool, 'default') }}:
+      vmImage: 'ubuntu-20.04'
+
+  variables:
+    DIFF_COVER_CHECK_THRESHOLD: 0
+    DIFF_COVER_ENABLE: 'true'
+    DIFF_COVER_WORKING_DIRECTORY: $(System.DefaultWorkingDirectory)/gcov/
+
+  container:
+    image: sonicdev-microsoft.azurecr.io:443/${{ parameters.sonic_slave }}:latest
+  
+
+  steps:
+  - script: |
+        set -ex
+        # Install .NET CORE
+        curl -sSL https://packages.microsoft.com/keys/microsoft.asc | sudo apt-key add -
+        sudo apt-add-repository https://packages.microsoft.com/debian/10/prod
+        sudo apt-get update
+        sudo apt-get install -y dotnet-sdk-5.0
+    displayName: "Install .NET CORE"
+  - script: |
+      sudo apt-get install -y lcov
+    displayName: "Install dependencies"
+    condition: eq('${{ parameters.archive_gcov }}', true)
+  - task: DownloadPipelineArtifact@2
+    inputs:
+      artifact: ${{ parameters.artifact_name }}
+    displayName: "Download gcov artifact"
+    condition: eq('${{ parameters.archive_gcov }}', true)
+  - script: |
+      set -x
+      ls -lh
+      sudo tar -zxvf sonic-gcov.tar.gz
+      sudo cp -rf sonic-gcov $(Build.ArtifactStagingDirectory)
+      sudo rm sonic-gcov.tar.gz
+      ls -lh
+    workingDirectory: $(Pipeline.Workspace)
+    displayName: "store sonic-gcov"
+    condition: eq('${{ parameters.archive_gcov }}', true)
+  - checkout: self
+    submodules: true
+    condition: eq('${{ parameters.archive_gcov }}', true)
+  - script: |
+      set -x
+      wget https://packages.microsoft.com/config/debian/10/packages-microsoft-prod.deb -O packages-microsoft-prod.deb
+      sudo dpkg -i packages-microsoft-prod.deb
+      sudo apt-get update
+      sudo apt-get install -y dotnet-sdk-5.0
+      pushd ./s/
+      sudo tar -zcvf swss.tar.gz ./*
+      ls -lh ./*
+      cp ./gcovpreload/lcov_cobertura.py $(Build.ArtifactStagingDirectory)/
+      cp ./tests/gcov_support.sh $(Build.ArtifactStagingDirectory)/sonic-gcov
+      sudo cp -rf swss.tar.gz $(Build.ArtifactStagingDirectory)/sonic-gcov
+      popd
+      sudo cp -rf $(Build.ArtifactStagingDirectory)/sonic-gcov ./
+      pushd sonic-gcov
+      ls -lh ./*
+      sudo chmod +x ./gcov_support.sh
+      sudo ./gcov_support.sh generate
+      sudo ./gcov_support.sh merge_container_info $(Build.ArtifactStagingDirectory)
+      sudo cp -rf gcov_output $(Build.ArtifactStagingDirectory)
+      mkdir -p $(System.DefaultWorkingDirectory)/gcov
+      sudo cp -rf $(Build.ArtifactStagingDirectory)/gcov_output/AllMergeReport/* $(System.DefaultWorkingDirectory)/gcov/
+      ls -lh $(Build.ArtifactStagingDirectory)
+      popd
+    workingDirectory: $(Pipeline.Workspace)
+    displayName: "generate gcov reports"
+    condition: eq('${{ parameters.archive_gcov }}', true)
+
+  - publish: $(Build.ArtifactStagingDirectory)/gcov_output
+    artifact: gcov_info
+    displayName: "Archive gcov info"
+    condition: eq('${{ parameters.archive_gcov }}', true)
+
+  - task: PublishCodeCoverageResults@1
+    inputs:
+      codeCoverageTool: Cobertura
+      summaryFileLocation: '$(Build.ArtifactStagingDirectory)/gcov_output/AllMergeReport/coverage.xml'
+      reportDirectory: '$(Build.ArtifactStagingDirectory)/gcov_output/AllMergeReport/'
+    displayName: 'Publish c c++ test coverage'
+    condition: eq('${{ parameters.archive_gcov }}', true)
+  
diff --git a/.azure-pipelines/test-docker-sonic-vs-template.yml b/.azure-pipelines/test-docker-sonic-vs-template.yml
index d5db0e1c8f..237778af4a 100644
--- a/.azure-pipelines/test-docker-sonic-vs-template.yml
+++ b/.azure-pipelines/test-docker-sonic-vs-template.yml
@@ -1,11 +1,21 @@
 parameters:
 - name: timeout
   type: number
-  default: 180
+  default: 240
 
 - name: log_artifact_name
   type: string
 
+- name: gcov_artifact_name
+  type: string
+
+- name: sonic_slave
+  type: string
+
+- name: archive_gcov
+  type: boolean
+  default: false
+
 jobs:
 - job:
   displayName: vstest
@@ -53,7 +63,12 @@ jobs:
       sudo /sbin/ip link add Vrf1 type vrf table 1001 || { echo 'vrf command failed' ; exit 1; }
       sudo /sbin/ip link del Vrf1 type vrf table 1001
       pushd tests
-      sudo py.test -v --force-flaky --junitxml=tr.xml --imgname=docker-sonic-vs:$(Build.DefinitionName).$(Build.BuildNumber)
+
+      if [ '${{ parameters.archive_gcov }}' == True ]; then
+        sudo py.test -v --force-flaky --junitxml=tr.xml --keeptb --imgname=docker-sonic-vs:$(Build.DefinitionName).$(Build.BuildNumber)
+      else
+        sudo py.test -v --force-flaky --junitxml=tr.xml --imgname=docker-sonic-vs:$(Build.DefinitionName).$(Build.BuildNumber)
+      fi
     displayName: "Run vs tests"
 
   - task: PublishTestResults@2
@@ -64,9 +79,21 @@ jobs:
 
   - script: |
       cp -r tests/log $(Build.ArtifactStagingDirectory)/
+
+      if [ '${{ parameters.archive_gcov }}' == True ]; then
+        sudo apt-get install -y lcov
+        ./tests/gcov_support.sh set_environment $(Build.ArtifactStagingDirectory)
+        docker stop $(docker ps -q -a)
+        docker rm $(docker ps -q -a)
+      fi
     displayName: "Collect logs"
     condition: always()
 
+  - publish: $(Build.ArtifactStagingDirectory)/gcov_tmp
+    artifact: ${{ parameters.gcov_artifact_name }}
+    displayName: "Publish gcov output"
+    condition: eq('${{ parameters.archive_gcov }}', true)
+
   - publish: $(Build.ArtifactStagingDirectory)/
     artifact: ${{ parameters.log_artifact_name }}@$(System.JobAttempt)
     displayName: "Publish logs"
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index a8cfe15cb2..6db3c6bda5 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -6,7 +6,21 @@
 trigger:
   branches:
     include:
-      - "*"
+      - master
+      - 20????
+pr:
+  branches:
+    include:
+      - master
+      - 20????
+schedules:
+- cron: "0 0 * * 0"
+  displayName: Weekly Sunday build
+  branches:
+    include:
+      - master
+      - 20????
+  always: true
 
 stages:
 - stage: Build
@@ -16,14 +30,16 @@ stages:
     parameters:
       arch: amd64
       sonic_slave: sonic-slave-buster
+      buildimage_artifact_name: sonic-buildimage.vs
+      buildimage_pipeline: 142
       swss_common_artifact_name: sonic-swss-common
       sairedis_artifact_name: sonic-sairedis
       artifact_name: sonic-swss
       archive_pytests: true
+      archive_gcov: true
 
 - stage: BuildArm
-  dependsOn: Build
-  condition: succeeded('Build')
+  dependsOn: []
   jobs:
   - template: .azure-pipelines/build-template.yml
     parameters:
@@ -31,9 +47,12 @@ stages:
       timeout: 240
       pool: sonicbld-armhf
       sonic_slave: sonic-slave-buster-armhf
+      buildimage_artifact_name: sonic-buildimage.marvell-armhf
+      buildimage_pipeline: 141
       swss_common_artifact_name: sonic-swss-common.armhf
       sairedis_artifact_name: sonic-sairedis.armhf
       artifact_name: sonic-swss.armhf
+      archive_gcov: false
 
   - template: .azure-pipelines/build-template.yml
     parameters:
@@ -42,8 +61,11 @@ stages:
       pool: sonicbld-arm64
       sonic_slave: sonic-slave-buster-arm64
       swss_common_artifact_name: sonic-swss-common.arm64
+      buildimage_artifact_name: sonic-buildimage.centec-arm64
+      buildimage_pipeline: 140
       sairedis_artifact_name: sonic-sairedis.arm64
       artifact_name: sonic-swss.arm64
+      archive_gcov: false
 
 - stage: BuildDocker
   dependsOn: Build
@@ -63,3 +85,20 @@ stages:
   - template: .azure-pipelines/test-docker-sonic-vs-template.yml
     parameters:
       log_artifact_name: log
+      gcov_artifact_name: sonic-gcov
+      sonic_slave: sonic-slave-buster
+      archive_gcov: true
+
+- stage: Gcov
+  dependsOn: Test
+  condition: always()
+  jobs:
+  - template: .azure-pipelines/gcov.yml
+    parameters:
+      arch: amd64
+      sonic_slave: sonic-slave-buster
+      swss_common_artifact_name: sonic-swss-common
+      sairedis_artifact_name: sonic-sairedis
+      swss_artifact_name: sonic-swss
+      artifact_name: sonic-gcov
+      archive_gcov: true