diff --git a/.github/workflows/cache-clean.yml b/.github/workflows/cache-clean.yml
new file mode 100644
index 0000000000..fcb54cf00b
--- /dev/null
+++ b/.github/workflows/cache-clean.yml
@@ -0,0 +1,25 @@
+name: Cache clean
+
+on:
+  workflow_dispatch:
+
+jobs:
+  cleanup:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Cleanup
+        run: |
+          gh extension install actions/gh-actions-cache
+
+          echo "Fetching list of cache keys"
+          cacheKeys=$(gh actions-cache list -R $REPO -L 100 | grep -v develop | cut -f 1 )
+
+          echo "Deleting caches..."
+          set +e
+          for cacheKey in $cacheKeys; do
+            gh actions-cache delete "$cacheKey" -R "$REPO" --confirm
+          done
+          echo "Done"
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          REPO: ${{ github.repository }}
diff --git a/.github/workflows/cache-rebuild.yml b/.github/workflows/cache-rebuild.yml
new file mode 100644
index 0000000000..8bac555e3a
--- /dev/null
+++ b/.github/workflows/cache-rebuild.yml
@@ -0,0 +1,97 @@
+name: Cache rebuild
+
+on:
+  workflow_dispatch:
+    inputs:
+      clean_all:
+        description: 'Clean all caches, not just esp32 ones'
+        default: false
+
+jobs:
+  cleanup:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Cleanup
+        id: cleanup
+        run: |
+          gh extension install actions/gh-actions-cache
+
+          echo "Fetching list of cache keys"
+          if [ -z "$CLEAN_ALL" ]; then
+            cacheKeys=$(gh actions-cache list -R "$REPO" -L 100 | cut -f 1 )
+          else
+            cacheKeys=$(gh actions-cache list -R "$REPO" -L 100 | grep -w "idf\|esp32" | cut -f 1 )
+          fi
+
+          echo "Deleting caches..."
+          set +e
+          for cacheKey in $cacheKeys; do
+            gh actions-cache delete "$cacheKey" -R "$REPO" --confirm
+          done
+          echo "Done"
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          REPO: ${{ github.repository }}
+          CLEAN_ALL: ${{ inputs.clean_all }}
+
+  build:
+    needs: cleanup
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        idf_version: ["4.4", "5.2"]
+        include:
+          - os: ubuntu-latest
+            idf_version: "4.3"
+          - os: ubuntu-latest
+            idf_version: "5.0"
+        exclude:
+          - os: macos-latest
+            idf_version: "4.4"
+
+    runs-on: ${{ matrix.os }}
+
+    env:
+      SMING_ARCH: Esp32
+      SMING_SOC: esp32
+      INSTALL_IDF_VER: ${{ matrix.idf_version }}
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Setup python
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ matrix.idf_version == '4.3' && '3.8' || '3.12' }}
+
+    - name: Configure environment
+      shell: pwsh
+      run: |
+        "CI_BUILD_DIR=" + (Resolve-Path ".").path >> $env:GITHUB_ENV
+        "SMING_HOME=" + (Resolve-Path "Sming").path >> $env:GITHUB_ENV
+
+    - name: Fix permissions
+      if: matrix.os != 'windows-latest'
+      run: |
+        sudo chown $USER /opt
+
+    - name: Install build tools for Ubuntu / MacOS
+      if: matrix.os != 'windows-latest'
+      run: |
+        Tools/ci/install.sh
+
+    - name: Install build tools for Windows
+      if: matrix.os == 'windows-latest'
+      run: |
+         . Tools/ci/setenv.ps1
+         Tools/ci/install.cmd
+
+    - name: Cache ESP-IDF and build tools
+      uses: actions/cache/save@v4
+      with:
+        path: |
+          /opt/esp-idf-${{ matrix.idf_version }}
+          /opt/esp32
+        key: ${{ matrix.os }}-idf-${{ matrix.idf_version }}
diff --git a/.github/workflows/ci-esp32.yml b/.github/workflows/ci-esp32.yml
index 1644494eff..38f4c0d012 100644
--- a/.github/workflows/ci-esp32.yml
+++ b/.github/workflows/ci-esp32.yml
@@ -2,7 +2,9 @@ name: Continuous Integration (CI) for Esp32
 
 on:
   push:
-  
+
+  workflow_dispatch:
+
   pull_request:
     branches: [ develop ]
 
@@ -38,6 +40,7 @@ jobs:
       SMING_ARCH: Esp32
       SMING_SOC: ${{ matrix.variant }}
       INSTALL_IDF_VER: ${{ matrix.idf_version }}
+      IDF_SKIP_CHECK_SUBMODULES: 1
       ENABLE_CCACHE: 1
 
     steps:
@@ -60,7 +63,7 @@ jobs:
         "SMING_HOME=" + (Resolve-Path "Sming").path >> $env:GITHUB_ENV
 
     - name: Fix permissions
-      if: ${{ matrix.os != 'windows-latest' }}
+      if: matrix.os != 'windows-latest'
       run: |
         sudo chown $USER /opt
 
@@ -72,30 +75,34 @@ jobs:
           /opt/esp32
         key: ${{ matrix.os }}-idf-${{ matrix.idf_version }}
 
+    - name: Compiler Cache
+      uses: actions/cache@v4
+      with:
+        path: .ccache
+        key: ${{ matrix.os }}-ccache-${{ matrix.variant }}-${{ matrix.idf_version }}
+
     - name: Install build tools for Ubuntu / MacOS
-      if: ${{ matrix.os != 'windows-latest' }}
+      if: matrix.os != 'windows-latest'
       run: |
         Tools/ci/install.sh
 
-    - name: Install build tools for Windows   
-      if: ${{ matrix.os == 'windows-latest' }}
+    - name: Install build tools for Windows
+      if: matrix.os == 'windows-latest'
       run: |
          . Tools/ci/setenv.ps1
          Tools/ci/install.cmd
 
-    - name: ccache
-      uses: hendrikmuhs/ccache-action@v1.2
-      with:
-        key: ${{ matrix.os }}-${{ matrix.variant }}-${{ matrix.idf_version }}
-
     - name: Build and test for ${{matrix.variant}} with IDF v${{matrix.idf_version}} on Ubuntu / MacOS
-      if: ${{ matrix.os != 'windows-latest' }}
+      if: matrix.os != 'windows-latest'
       run: |
         source $SMING_HOME/../Tools/export.sh
         Tools/ci/build.sh
 
     - name: Build and test for ${{matrix.variant}} with IDF v${{matrix.idf_version}} on Windows
-      if: ${{ matrix.os == 'windows-latest' }}
+      if: matrix.os == 'windows-latest'
       run: |
         . Tools/ci/setenv.ps1
         Tools/ci/build.cmd
+
+    - name: Compiler Cache stats
+      run: ccache -sv
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 608d6286e7..787923a590 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,7 +2,9 @@ name: Continuous Integration (CI)
 
 on:
   push:
-  
+
+  workflow_dispatch:
+
   pull_request:
     branches: [ develop ]
 
@@ -30,7 +32,7 @@ jobs:
           - variant: rp2040
             arch: Rp2040
 
-    concurrency: 
+    concurrency:
       group: ${{ github.workflow }}-${{ github.ref }}-${{ toJson(matrix) }}
       cancel-in-progress: true
 
@@ -62,32 +64,36 @@ jobs:
         "CI_BUILD_DIR=" + (Resolve-Path ".").path >> $env:GITHUB_ENV
         "SMING_HOME=" + (Resolve-Path "Sming").path >> $env:GITHUB_ENV
 
+    - name: Compiler Cache
+      uses: actions/cache@v4
+      with:
+        path: .ccache
+        key: ${{ matrix.os }}-ccache-${{ matrix.toolchain }}-${{ matrix.variant }}
+
     - name: Install build tools for Ubuntu / MacOS
-      if: ${{ matrix.os != 'windows-latest' }}
+      if: matrix.os != 'windows-latest'
       run: |
         Tools/ci/install.sh
 
-    - name: Install build tools for Windows   
-      if: ${{ matrix.os == 'windows-latest' }}
+    - name: Install build tools for Windows
+      if: matrix.os == 'windows-latest'
       run: |
          . Tools/ci/setenv.ps1
          Tools/ci/install.cmd
 
-    - name: ccache
-      uses: hendrikmuhs/ccache-action@v1.2
-      with:
-        key: ${{ matrix.os }}-${{ matrix.toolchain }}-${{ matrix.variant }}
-
     - name: Build and test for ${{matrix.variant}} on Ubuntu / MacOS
       env:
         CLANG_FORMAT: clang-format-8
-      if: ${{ matrix.os != 'windows-latest' }}
+      if: matrix.os != 'windows-latest'
       run: |
         source $SMING_HOME/../Tools/export.sh
         Tools/ci/build.sh
 
     - name: Build and test for ${{matrix.variant}} on Windows
-      if: ${{ matrix.os == 'windows-latest' }}
+      if: matrix.os == 'windows-latest'
       run: |
         . Tools/ci/setenv.ps1
         Tools/ci/build.cmd
+
+    - name: Compiler Cache stats
+      run: ccache -sv
diff --git a/.github/workflows/coverity-scan.yml b/.github/workflows/coverity-scan.yml
index 21b710e246..daa11e047b 100644
--- a/.github/workflows/coverity-scan.yml
+++ b/.github/workflows/coverity-scan.yml
@@ -44,19 +44,19 @@ jobs:
         echo "CHECK_SCA=$CHECK_SCA" >> $GITHUB_ENV
 
     - name: Setup SMING_HOME for Ubuntu
-      if: ${{ env.CHECK_SCA == 1 }}
+      if: env.CHECK_SCA == 1
       run: |
         echo "CI_BUILD_DIR=$GITHUB_WORKSPACE" >> $GITHUB_ENV
         echo "SMING_HOME=$GITHUB_WORKSPACE/Sming" >> $GITHUB_ENV
         echo "SMING_ARCH=Host" >> $GITHUB_ENV
 
     - name: Install Sming Framework on Ubuntu
-      if: ${{ env.CHECK_SCA == 1 }}
+      if: env.CHECK_SCA == 1
       run:  |
         Tools/ci/install.sh
 
     - name: Run Coverity Scan
-      if: ${{ env.CHECK_SCA == 1 }}
+      if: env.CHECK_SCA == 1
       env:
           COVERITY_SCAN_TOKEN: ${{secrets.COVERITY_SCAN_TOKEN}}
       run: |
@@ -67,7 +67,7 @@ jobs:
         $SMING_HOME/Arch/Host/Tools/ci/coverity-scan.sh
 
     - name: Archive scan log
-      if: ${{ env.CHECK_SCA == 1 }}
+      if: env.CHECK_SCA == 1
       uses: actions/upload-artifact@v3
       with:
         name: coverity-scan-report
diff --git a/.github/workflows/library.yml b/.github/workflows/library.yml
index 295da95f56..d4bb144771 100644
--- a/.github/workflows/library.yml
+++ b/.github/workflows/library.yml
@@ -62,7 +62,7 @@ jobs:
           - os: macos-latest
             idf_version: "4.4"
 
-    concurrency: 
+    concurrency:
       group: ${{ github.workflow }}-${{ github.ref }}-${{ toJson(matrix) }}
       cancel-in-progress: true
 
@@ -89,7 +89,7 @@ jobs:
         python-version: "3.12"
 
     - name: Create library alias
-      if: ${{ inputs.alias }}
+      if: inputs.alias
       shell: pwsh
       run: |
         New-Item -ItemType SymbolicLink -Path "../${{ inputs.alias }}" -Target (Resolve-Path ".").path
@@ -107,12 +107,12 @@ jobs:
         "CI_MAKEFILE=" + (Resolve-Path "../../sming/Tools/ci/library/Makefile") >> $env:GITHUB_ENV
 
     - name: Fix permissions
-      if: ${{ matrix.os != 'windows-latest' }}
+      if: matrix.os != 'windows-latest'
       run: |
         sudo chown $USER /opt
 
     - name: Cache ESP-IDF and build tools
-      if: ${{ matrix.arch == 'Esp32' }}
+      if: matrix.arch == 'Esp32'
       uses: actions/cache@v4
       with:
         path: |
@@ -121,12 +121,12 @@ jobs:
         key: ${{ matrix.os }}-idf-${{ env.INSTALL_IDF_VER }}
 
     - name: Install build tools for Ubuntu / MacOS
-      if: ${{ matrix.os != 'windows-latest' }}
+      if: matrix.os != 'windows-latest'
       run: |
         $SMING_HOME/../Tools/ci/install.sh
 
-    - name: Install build tools for Windows   
-      if: ${{ matrix.os == 'windows-latest' }}
+    - name: Install build tools for Windows
+      if: matrix.os == 'windows-latest'
       run: |
         cd $env:SMING_HOME/..
         . Tools/ci/setenv.ps1
@@ -135,13 +135,13 @@ jobs:
     - name: Build and Test for ${{matrix.arch}} on Ubuntu / MacOS
       env:
         CLANG_FORMAT: clang-format-8
-      if: ${{ matrix.os != 'windows-latest' }}
+      if: matrix.os != 'windows-latest'
       run: |
         source $SMING_HOME/../Tools/export.sh
         make -j$(nproc) -f $CI_MAKEFILE
 
     - name: Build and Test for ${{matrix.arch}} on Windows
-      if: ${{ matrix.os == 'windows-latest' }}
+      if: matrix.os == 'windows-latest'
       run: |
         . "$env:SMING_HOME/../Tools/ci/setenv.ps1"
         make -j $env:NUMBER_OF_PROCESSORS -f $env:CI_MAKEFILE
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index ef9127ad64..8f2d4dee10 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -5,7 +5,7 @@ on:
   push:
     tags:
       - '[0-9]+.[0-9]+.[0-9]+'
-      
+
 # TODO: check if the tag is pointing to the tip of the master branch
 
 jobs:
@@ -14,22 +14,22 @@ jobs:
     steps:
     - uses: actions/checkout@v4
     - uses: trstringer/manual-approval@v1
-      if: ${{ github.ref_type == 'tag' }}
+      if: github.ref_type == 'tag'
       with:
          secret: ${{ github.TOKEN }}
          approvers: slaff
     - name: Install xmlstarlet
-      if: ${{ github.ref_type == 'tag' }}
+      if: github.ref_type == 'tag'
       run: sudo apt-get install -y jq xmlstarlet
     - name: Build docs
-      if: ${{ github.ref_type == 'tag' }}
+      if: github.ref_type == 'tag'
       run: |
         Tools/install.sh doc
         make -C docs html
         zip -r sming-docs.zip docs/build/html
     - name: Release New Version
-      if: ${{ github.ref_type == 'tag' }}
-      env: 
+      if: github.ref_type == 'tag'
+      env:
         SMING_ARCH: Host
         RELEASE_TOKEN: ${{secrets.RELEASE_TOKEN}}
         CI_REPO_NAME: ${{github.repository}}
diff --git a/Sming/Arch/Esp32/Tools/install.cmd b/Sming/Arch/Esp32/Tools/install.cmd
index 9952a151c6..27fafbb755 100644
--- a/Sming/Arch/Esp32/Tools/install.cmd
+++ b/Sming/Arch/Esp32/Tools/install.cmd
@@ -33,6 +33,13 @@ goto :setup
 
 :setup
 
+REM Skip installation for CI if already present
+if "%CI_BUILD_DIR%" NEQ "" (
+    if exist "%IDF_TOOLS_PATH%\tools" (
+        goto :EOF
+    )
+)
+
 REM Install IDF tools and packages
 python "%IDF_PATH%\tools\idf_tools.py" --non-interactive install
 python -m pip install %SMINGTOOLS%/gevent-1.5.0-cp39-cp39-win_amd64.whl
diff --git a/Sming/Arch/Esp32/Tools/install.sh b/Sming/Arch/Esp32/Tools/install.sh
index 82bab550fd..7932363311 100755
--- a/Sming/Arch/Esp32/Tools/install.sh
+++ b/Sming/Arch/Esp32/Tools/install.sh
@@ -60,6 +60,10 @@ fi
 rm -f "$IDF_PATH"
 ln -s "$IDF_CLONE_PATH" "$IDF_PATH"
 
+
+# Skip installation for CI if already present
+if [ -z "$CI_BUILD_DIR" ] || [ ! -d "$IDF_TOOLS_PATH/tools" ]; then
+
 # Install IDF tools and packages
 python3 "$IDF_PATH/tools/idf_tools.py" --non-interactive install
 if [ -n "$VIRTUAL_ENV" ]; then
@@ -73,4 +77,6 @@ if [ -z "$KEEP_DOWNLOADS" ]; then
     rm -rf "$IDF_TOOLS_PATH/dist"
 fi
 
+fi # CI install
+
 fi
diff --git a/Tools/ci/README.rst b/Tools/ci/README.rst
index 00e9e67ace..f8e39c3281 100644
--- a/Tools/ci/README.rst
+++ b/Tools/ci/README.rst
@@ -1,8 +1,69 @@
-CI logs
-=======
+Continuous Integration testing
+==============================
+
+Github actions
+--------------
+
+See ``.github/workflows``.
+
+Cache clean
+      Dispatch workflow to remove caches for pull requests, but leave those for the default (develop) branch intact.
+
+Cache rebuild
+      Dispatch workflow to rebuild the esp32 idf/tool caches.
+      By default, cleans only idf/esp32 caches but has option to perform full clean.
+
+CodeQL
+      Performs code quality analysis when develop branch is updated.
+
+Continuous Integration (CI)
+      Tests for all architectures except esp32. Run for every pull request and merge to develop.
+
+Continuous Integration (CI) for Esp32
+      Tests for esp32 architecture. Requires a separate workflow as matrix becomes too complex otherwise.
+
+Continuous Integration (CI) for Library
+      Used indirectly by library workflows for testing. See workflows/library.
+
+Coverity Scan
+      Code quality analyser. Does instrumented build then uploads database to coverity servers for analysis.
+
+Release
+      Run manually during release phase only.
+
+Spelling Check
+      Run for all pull requests and merge to develop.
+
 
-Overview
---------
+Esp32 IDF and tools cleaning
+----------------------------
+
+Because the IDF and associated tools are large and relatively time-consuming to install, these are cached.
+There's so much bloat that it doesn't take much to fill the 10GB github cache allocation.
+
+So after installing the tools - before it gets cached - the `clean-tools.py` script gets run.
+This tool contains a list of filters (regular expressions) which match various paths.
+Candidates for removal were identified by inspection using the Gnome disk usage analyzer.
+Some other stuff (like test code and examples) are fairly safe candidates to remove as well.
+
+To evaluate how much would be removed run this command (it's safe)::
+
+      python clean-tools.py scan
+
+To perform 'dry-run' of a clean operation, without actually deleteing anything::
+
+      python clean-tools.py clean
+
+To actually delete stuff requires a confirmation flag::
+
+      python clean-tools.py clean --delete
+
+Note that some unused submodules are cleaned, but by default the IDF pulls them back in again!
+To prevent this behaviour, set `IDF_SKIP_CHECK_SUBMODULES=1`.
+
+
+CI logs
+-------
 
 Analysing CI logs is important for several reasons:
 
@@ -23,7 +84,7 @@ The log files related to a run and therefore only two are required (the main bui
 
 
 Setup
------
+~~~~~
 
 The github CLI client must be installed and authenticated with the Sming repo (or fork).
 
@@ -31,7 +92,7 @@ See https://docs.github.com/en/github-cli/github-cli/quickstart.
 
 
 Usage
------
+~~~~~
 
 Fetch and scan the most recent build::
 
@@ -67,7 +128,7 @@ The named exclusion file contains a list of regular expressions to match against
 
 
 vscode
-------
+~~~~~
 
 The warnings output using the scanlog tool can be used as hyperlinks in vscode:
 
diff --git a/Tools/ci/clean-tools.py b/Tools/ci/clean-tools.py
index 1654b37b50..75762ca914 100644
--- a/Tools/ci/clean-tools.py
+++ b/Tools/ci/clean-tools.py
@@ -5,53 +5,75 @@
 import shutil
 import argparse
 
+# Mandatory environment variables
+IDF_PATH = os.environ['IDF_PATH']
+IDF_TOOLS_PATH = os.environ['IDF_TOOLS_PATH']
+
 # The commented-out ARC paths below are for regular libraries with RTTI.
 # These are used by default without the -fno-rtti switch so without them the cmake
 # compiler check fails. Otherwise they can go.
 TOOLS = r'esp32/tools/'
 IDF = r'esp-idf([^/]+)/'
+
 ARC = r'([^/]+)\.a'
-FILTERS = [
-    # Leave versioned directory to avoid re-installation
-    rf'{TOOLS}.*esp-elf-gdb/.*/.*esp-elf-gdb/',
-    rf'{TOOLS}esp32ulp-elf/.*/esp32ulp-elf/',
-    rf'{TOOLS}openocd-esp32/.*/openocd-esp32/',
-    # Libraries not required by Sming
-    # rf'{TOOLS}.*/riscv32-esp-elf/lib/{ARC}',
-    rf'{TOOLS}.*/riscv32-esp-elf/lib/rv32i_.*',
-    rf'{TOOLS}.*/riscv32-esp-elf/lib/rv32i/',
-    rf'{TOOLS}.*/riscv32-esp-elf/lib/rv32imac_.*',
-    rf'{TOOLS}.*/riscv32-esp-elf/lib/rv32imafc_.*',
-    rf'{TOOLS}.*/riscv32-esp-elf/lib/rv32imafc/',
-    # rf'{TOOLS}.*/riscv32-esp-elf/lib/rv32imc_zicsr_zifencei/ilp32/{ARC}',
-    # rf'{TOOLS}.*/riscv32-esp-elf/lib/rv32imc/ilp32/{ARC}',
-    # rf'{TOOLS}.*/lib/esp32/{ARC}',
-    rf'{TOOLS}.*/lib/esp32-psram',
-    rf'{TOOLS}.*/lib/esp32/psram',
-    # rf'{TOOLS}.*/lib/esp32s2/{ARC}',
-    # rf'{TOOLS}.*/lib/esp32s3/{ARC}',
-    # rf'{TOOLS}.*/xtensa-esp32-elf/lib/{ARC}',
-    # rf'{TOOLS}.*/xtensa-esp32s2-elf/lib/{ARC}',
-    # rf'{TOOLS}.*/xtensa-esp32s3-elf/lib/{ARC}',
-    # rf'{TOOLS}.*/xtensa-esp-elf/lib/{ARC}',
-    # Components, examples and archives
-    rf'{IDF}docs/',
-    rf'{IDF}examples/',
-    rf'{IDF}components/cmock/',
-    rf'{IDF}components/unity/',
-    rf'{IDF}.*esp32c6.*',
-    rf'{IDF}.*esp32h2.*',
-    rf'{IDF}.*esp32p4.*',
-    rf'{IDF}.*/tests',
-]
-
-# Python 3.8 doesn't have str.removeprefix
-def removeprefix(path: str, prefix: str) -> str:
-    return path[len(prefix):] if path.startswith(prefix) else path
+
+# These filters are matched from the **start** of the path so there's an implicit .* at the end
+FILTERS = {
+    IDF_TOOLS_PATH: [
+        # Leave versioned directory to avoid re-installation
+        r'.*esp-elf-gdb/.*/.*esp-elf-gdb/',
+        r'esp32ulp-elf/.*/esp32ulp-elf/',
+        r'openocd-esp32/.*/openocd-esp32/',
+        # Libraries not required by Sming
+        # r'.*/riscv32-esp-elf/lib/{ARC}',
+        r'.*/riscv32-esp-elf/lib/rv32i_.*',
+        r'.*/riscv32-esp-elf/lib/rv32i/',
+        r'.*/riscv32-esp-elf/lib/rv32imac_.*',
+        r'.*/riscv32-esp-elf/lib/rv32imafc_.*',
+        r'.*/riscv32-esp-elf/lib/rv32imafc/',
+        # r'.*/riscv32-esp-elf/lib/rv32imc_zicsr_zifencei/ilp32/{ARC}',
+        # r'.*/riscv32-esp-elf/lib/rv32imc/ilp32/{ARC}',
+        # r'.*/lib/esp32/{ARC}',
+        r'.*/lib/esp32(-|/)psram',
+        # r'.*/lib/esp32s2/{ARC}',
+        # r'.*/lib/esp32s3/{ARC}',
+        # r'.*/xtensa-esp32-elf/lib/{ARC}',
+        # r'.*/xtensa-esp32s2-elf/lib/{ARC}',
+        # r'.*/xtensa-esp32s3-elf/lib/{ARC}',
+        # r'.*/xtensa-esp-elf/lib/{ARC}',
+    ],
+    IDF_PATH: [
+        # Components, examples and archives
+        r'docs/',
+        r'.*/doc',
+        r'examples/',
+        r'components/asio/',
+        r'components/cmock/',
+        r'components/openthread/openthread/third_party',
+        r'components/unity/',
+        r'components/.*esp32c6.*',
+        r'components/.*esp32h2.*',
+        r'components/.*esp32p4.*',
+        r'components/.*/test',
+        r'components/.*/fuzz',
+        r'components/expat/expat/testdata',
+        r'components/libsodium',
+        r'components/nghttp/nghttp2/third-party/mruby',
+        r'components/nghttp/nghttp2/third-party',
+        r'components/tinyusb/',
+        r'components/.*/win32',
+        r'tools/esp_app_trace',
+        r'tools/test',
+        r'tools/ci',
+    ]
+}
+
+def fix_path(path: str) -> str:
+    return path[2:].replace('\\', '/') if path[1] == ':' else path
 
 
 def scan_log(logfile: str, file_list: dict):
-    with open(logfile, 'r') as f:
+    with open(logfile, 'r', encoding='utf8') as f:
         for path in f:
             path = path.strip()
             try:
@@ -59,10 +81,8 @@ def scan_log(logfile: str, file_list: dict):
                 path, _, size = path.rpartition(' ')
                 blocks = int(blocks)
                 size = int(size)
-                if path[1] == ':':
-                    path = path[2:].replace('\\', '/')
-                path = removeprefix(path, '/opt/')
-                if not path.startswith('esp'):
+                path = fix_path(path)
+                if '/esp' not in path:
                     continue
                 existing = file_list.get(path)
                 if not existing or size > existing:
@@ -80,20 +100,15 @@ def scan_logs(log_dir) -> dict:
     return file_list
 
 
-def scan_tools_dir(tools_dir) -> dict:
-    file_list = {}
+def scan_tree(start_path: str, file_list: dict):
     def scan(root_path):
         for entry in os.scandir(root_path):
             if entry.is_dir():
                 scan(entry.path)
                 continue
-            path = entry.path
-            path = removeprefix(path, tools_dir + '/')
-            if not path.startswith('esp'):
-                continue
-            path = path.replace('\\', '/')
+            path = fix_path(entry.path)
             file_list[path] = entry.stat().st_size
-    scan(tools_dir)
+    scan(start_path)
     return file_list
 
 
@@ -106,25 +121,33 @@ def mbstr(size) -> str:
 
     print(f'{len(file_list)} files, total size {mbstr(total_size)}')
 
-    total_size = 0
-    for flt in FILTERS:
-        expr = re.compile(flt)
-        size = sum(size for path, size in file_list.items() if expr.match(path))
-        total_size += size
-        print(f'{flt}: {mbstr(size)}')
+    def match(start_path: str, filters: list):
+        start_path = fix_path(start_path)
+        matched_size = 0
+        for flt in filters:
+            flt = rf'{start_path}/{flt}'
+            expr = re.compile(flt, flags=re.IGNORECASE)
+            size = sum(size for path, size in file_list.items() if expr.match(path))
+            matched_size += size
+            print(f'{flt}: {mbstr(size)}')
+        return matched_size
+
+    total_size = sum(match(*item) for item in FILTERS.items())
 
     print(f'Total size {mbstr(total_size)}')
 
 
-def clean_tools_dir(tools_dir: str, do_clean: bool):
-    re_filter = re.compile('|'.join(FILTERS))
+def clean_tree(start_path: str, filters: list, do_clean: bool):
+    if not os.path.exists(start_path):
+        print(f'"{start_path}" not found, skipping.')
+        return
+
+    re_filter = re.compile('|'.join(rf'{fix_path(start_path)}/{f}' for f in filters), flags=re.IGNORECASE)
 
     def clean_path(root_path):
         for entry in os.scandir(root_path):
             try:
-                path = entry.path
-                path = path.replace('\\', '/')
-                path = removeprefix(path, tools_dir.replace('\\', '/') + '/')
+                path = fix_path(entry.path)
                 if entry.is_dir():
                     if re_filter.match(path + '/'):
                         print(f"rmtree {entry.path}")
@@ -139,7 +162,7 @@ def clean_path(root_path):
             except Exception as e:
                 print(f'{repr(e)}')
 
-    clean_path(tools_dir)
+    clean_path(start_path)
 
 
 def main():
@@ -150,25 +173,25 @@ def main():
 
     args = parser.parse_args()
 
-    tools_dir = os.path.dirname(os.environ['IDF_PATH'])
-
-    print(f'Action: {args.action} "{tools_dir}"')
+    print(f'Action: {args.action}, IDF_PATH="{IDF_PATH}", IDF_TOOLS_PATH="{IDF_TOOLS_PATH}"')
 
     if args.action == 'scan':
         if args.logdir:
             file_list = scan_logs(args.logdir)
         else:
-            file_list = scan_tools_dir(tools_dir)
+            file_list = {}
+            scan_tree(IDF_PATH, file_list)
+            scan_tree(IDF_TOOLS_PATH, file_list)
         scan_list(file_list)
-    elif args.action == 'clean':
-        if not os.path.exists(tools_dir):
-            print(f'"{tools_dir}" not found, skipping.')
-            return
-        clean_tools_dir(tools_dir, args.delete)
+        return
+
+    if args.action == 'clean':
+        for path, filters in FILTERS.items():
+            clean_tree(path, filters, args.delete)
         if args.delete:
-            print("OK, items cleaned.")
+            print("** Cleaning finished.")
         else:
-            print("Dry run, nothing deleted.")
+            print("** Dry run, nothing deleted.")
 
 if __name__ == '__main__':
     main()
diff --git a/Tools/ci/install.cmd b/Tools/ci/install.cmd
index 7fe9f022a2..b1504673a6 100644
--- a/Tools/ci/install.cmd
+++ b/Tools/ci/install.cmd
@@ -10,4 +10,10 @@ if "%BUILD_DOCS%" == "true" (
 
 call %CI_BUILD_DIR%\Tools\install.cmd %SMING_ARCH% %INSTALL_OPTS%
 
+REM Configure ccache
+ccache --set-config cache_dir="%CI_BUILD_DIR%\.ccache"
+ccache --set-config max_size=500M
+ccache -z
+
+REM Clean up tools installation
 python "%CI_BUILD_DIR%\Tools\ci\clean-tools.py" clean --delete
diff --git a/Tools/ci/install.sh b/Tools/ci/install.sh
index 0cb02170cb..f94da42799 100755
--- a/Tools/ci/install.sh
+++ b/Tools/ci/install.sh
@@ -23,5 +23,11 @@ sudo chown "$USER" /opt
 
 fi
 
+# Configure ccache
+ccache --set-config cache_dir="$CI_BUILD_DIR/.ccache"
+ccache --set-config max_size=500M
+ccache -z
+
+# Clean up tools installation
 source "$CI_BUILD_DIR/Tools/export.sh"
 python "$CI_BUILD_DIR/Tools/ci/clean-tools.py" clean --delete