diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 77bf4b2..17c49a2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,28 +7,28 @@ on:
 
 jobs:
   ci:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     name: Erlang ${{matrix.otp}} / rebar ${{matrix.rebar3}}
     strategy:
       matrix:
-        otp: ['25', '26', '27']
+        otp: ['26', '27']
         rebar3: ['3']
         # latest rebar3 versions that do not give problems with selected OTPs
         include:
-          - otp: '23'
-            rebar3: '3.20.0'
           - otp: '24'
             rebar3: '3.23.0'
+          - otp: '25'
+            rebar3: '3.24.0'
     steps:
 
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - uses: erlef/setup-beam@v1
         with:
           otp-version: ${{matrix.otp}}
           rebar3-version: ${{matrix.rebar3}}
 
-      - uses: actions/cache@v2
+      - uses: actions/cache@v4
         env:
           cache-name: rebar3
         with:
diff --git a/src/grisp_tools_build.erl b/src/grisp_tools_build.erl
index a908f7f..78abfe3 100644
--- a/src/grisp_tools_build.erl
+++ b/src/grisp_tools_build.erl
@@ -45,6 +45,7 @@ run(Configuration) ->
             ]},
             {compile, [
                 fun configure/1,
+                fun update_preloaded/1,
                 fun boot/1,
                 fun install/1,
                 fun post/1
@@ -190,6 +191,12 @@ configure(#{build := Build, otp_version := {[Ver | _], _, _, _}} = S0) ->
             event(S0, ['_skip'])
     end.
 
+update_preloaded(#{build := #{flags := #{update_prebuild := true}}} = State0) ->
+    Opts = [{cd, mapz:deep_get([paths, build], State0)}],
+    build_step("./otp_build update_preloaded --no-commit", Opts, State0);
+update_preloaded(State0) ->
+    event(State0, ['_skip']).
+
 boot(State0) ->
     Opts = [{cd, mapz:deep_get([paths, build], State0)}],
     build_step("./otp_build boot -a", Opts, State0).
diff --git a/src/grisp_tools_step.erl b/src/grisp_tools_step.erl
index cb08a6e..48ea680 100644
--- a/src/grisp_tools_step.erl
+++ b/src/grisp_tools_step.erl
@@ -124,6 +124,19 @@ collect(#{project_root := Root, platform := Platform,
     mapz:deep_put([build, hash], #{value => Hash, index => HashIndex}, S3).
 
 toolchain(#{paths := #{toolchain := {docker, _}}} = S0) -> S0;
+toolchain(#{platform := grisp_nano,
+            paths := #{toolchain := {directory, ToolchainRoot}}} = S0) ->
+    [error({toolchain_root_invalid, ToolchainRoot}) || not filelib:is_dir(ToolchainRoot)],
+    Files = [
+        ["GRISP_TOOLCHAIN_REVISION"],
+        ["GRISP_TOOLCHAIN_PLATFORM"],
+        ["grisp_buildinfo.hrl"],
+        ["arm-rtems6"],
+        ["arm-rtems6", "stm32u5-grisp-nano"],
+        ["bin","arm-rtems6-gcc"]
+    ],
+    [ check_toolchain_file([ToolchainRoot|File]) || File <- Files],
+    S0;
 toolchain(#{paths := #{toolchain := {directory, ToolchainRoot}}} = S0) ->
     [error({toolchain_root_invalid, ToolchainRoot}) || not filelib:is_dir(ToolchainRoot)],
     Files = [