diff --git a/.dockerignore b/.dockerignore
index 0b73b065..517f5327 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -1,2 +1,2 @@
 machine-emulator-tools-*.ext2
-example/
+rootfs.*
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 21cf96be..3fdae091 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -3,6 +3,7 @@ on: [push]
 env:
   TOOLCHAIN_IMAGE: ${{ github.repository_owner }}/toolchain
   TOOLCHAIN_TAG: 0.16.0
+  TOOLS_IMAGE: ${{ github.repository_owner }}/machine-emulator-tools
 jobs:
   tools:
     runs-on: ubuntu-22.04
@@ -27,9 +28,6 @@ jobs:
       - name: Export makefile variables
         run: make env >> $GITHUB_ENV
 
-      - name: Download and check dependencies
-        run: make checksum
-
       - name: Buildx setup
         uses: docker/setup-buildx-action@v2
 
@@ -43,55 +41,50 @@ jobs:
             type=semver,pattern={{version}}
             type=semver,pattern={{major}}.{{minor}}
 
-      - name: Build [${{ env.MACHINE_EMULATOR_TOOLS_TAR_GZ }}]
+      - name: Build [${{ env.TOOLS_DEB }}]
         id: docker_build
         uses: docker/build-push-action@v4
         with:
           context: .
           builder: ${{ steps.buildx.outputs.name }}
-          tags: ${{ steps.docker_meta.outputs.tags }}
+          tags: ${{ env.TOOLS_IMAGE }}:devel.build
           push: false
           load: true
           build-args: |
-            MACHINE_EMULATOR_TOOLS_TAR_GZ=${{ env.MACHINE_EMULATOR_TOOLS_TAR_GZ }}
-            MACHINE_EMULATOR_TOOLS_DEB=${{ env.MACHINE_EMULATOR_TOOLS_DEB }}
-            MACHINE_EMULATOR_TOOLS_VERSION=${{ env.MACHINE_EMULATOR_TOOLS_VERSION }}
+            TOOLS_DEB=${{ env.TOOLS_DEB }}
             LINUX_SOURCES_VERSION=${{ env.LINUX_SOURCES_VERSION }}
-            LINUX_SOURCES_FILEPATH=${{ env.LINUX_SOURCES_FILEPATH }}
-            RNDADDENTROPY_VERSION=${{ env.RNDADDENTROPY_VERSION }}
-            RNDADDENTROPY_FILEPATH=${{ env.RNDADDENTROPY_FILEPATH }}
+            LINUX_SOURCES_URLPATH=${{ env.LINUX_SOURCES_URLPATH }}
           cache-from: type=gha,scope=regular,mode=max
           cache-to: type=gha,scope=regular
 
       - name: Retrieve artifacts
-        run: make copy MACHINE_EMULATOR_TOOLS_IMAGE=`echo "${{ steps.docker_meta.outputs.tags }}" | head -1 | cut -d "," -f 1 | xargs`
+        run: make copy TOOLS_IMAGE=${{ env.TOOLS_IMAGE }}:devel.build
 
-      - name: Upload [${{ env.MACHINE_EMULATOR_TOOLS_TAR_GZ }}]
+      - name: Upload [${{ env.TOOLS_DEB }}]
         uses: actions/upload-artifact@v3
         with:
-          name: ${{ env.MACHINE_EMULATOR_TOOLS_TAR_GZ }}
-          path: ${{ env.MACHINE_EMULATOR_TOOLS_TAR_GZ }}
+          name: ${{ env.TOOLS_DEB }}
+          path: ${{ env.TOOLS_DEB }}
 
-      - name: Upload [${{ env.MACHINE_EMULATOR_TOOLS_DEB }}]
+      - name: Upload rootfs.ext2
         uses: actions/upload-artifact@v3
         with:
-          name: ${{ env.MACHINE_EMULATOR_TOOLS_DEB }}
-          path: ${{ env.MACHINE_EMULATOR_TOOLS_DEB }}
+          name: rootfs.ext2
 
       - name: Checksum artifacts
         run: |
-          sha512sum ${{ env.MACHINE_EMULATOR_TOOLS_DEB }} > ${{ env.MACHINE_EMULATOR_TOOLS_DEB }}.sha512
-          sha512sum ${{ env.MACHINE_EMULATOR_TOOLS_TAR_GZ }} > ${{ env.MACHINE_EMULATOR_TOOLS_TAR_GZ }}.sha512
+          sha512sum ${{ env.TOOLS_DEB }} > ${{ env.TOOLS_DEB }}.sha512
+          sha512sum rootfs.ext2 > rootfs.ext2.sha512
 
       - uses: softprops/action-gh-release@v1
         if: startsWith(github.ref, 'refs/tags/v')
         with:
           prerelease: true
           files: |
-            ${{ env.MACHINE_EMULATOR_TOOLS_TAR_GZ }}
-            ${{ env.MACHINE_EMULATOR_TOOLS_TAR_GZ }}.sha512
-            ${{ env.MACHINE_EMULATOR_TOOLS_DEB }}
-            ${{ env.MACHINE_EMULATOR_TOOLS_DEB }}.sha512
+            ${{ env.TOOLS_DEB }}
+            ${{ env.TOOLS_DEB }}.sha512
+            rootfs.ext2
+            rootfs.ext2.sha512
 
   build:
     runs-on: ubuntu-22.04
diff --git a/.gitignore b/.gitignore
index caa32699..e5e72fef 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,7 +2,7 @@
 control
 machine-emulator-tools-*.tar.gz
 machine-emulator-tools-*.deb
-dep/
+rootfs.*
 
 # Prerequisites
 *.d
diff --git a/Dockerfile b/Dockerfile
index 7fa98c74..ee43e254 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -73,7 +73,7 @@ RUN cd ${BUILD_BASE}/tools/linux/rollup/http/rollup-http-server && \
 # pack tools (deb)
 # ------------------------------------------------------------------------------
 FROM c-builder as packer
-ARG MACHINE_EMULATOR_TOOLS_DEB=machine-emulator-tools.deb
+ARG TOOLS_DEB=machine-emulator-tools.deb
 ARG STAGING_BASE=${BUILD_BASE}/_install
 ARG STAGING_DEBIAN=${STAGING_BASE}/DEBIAN
 ARG STAGING_BIN=${STAGING_BASE}/opt/cartesi/bin
@@ -90,4 +90,4 @@ COPY --from=rust-builder ${BUILD_BASE}/tools/linux/rollup/http/rollup-http-serve
 COPY skel/ ${STAGING_BASE}/
 COPY control ${STAGING_DEBIAN}/control
 
-RUN dpkg-deb -Zxz --root-owner-group --build ${STAGING_BASE} ${BUILD_BASE}/${MACHINE_EMULATOR_TOOLS_DEB}
+RUN dpkg-deb -Zxz --root-owner-group --build ${STAGING_BASE} ${BUILD_BASE}/${TOOLS_DEB}
diff --git a/Makefile b/Makefile
index 96fd2064..3af5f607 100644
--- a/Makefile
+++ b/Makefile
@@ -20,50 +20,59 @@ PATCH := 0
 LABEL :=
 VERSION := $(MAJOR).$(MINOR).$(PATCH)$(LABEL)
 
-MACHINE_EMULATOR_TOOLS_VERSION ?= v$(VERSION)
-MACHINE_EMULATOR_TOOLS_DEB     := machine-emulator-tools-$(MACHINE_EMULATOR_TOOLS_VERSION).deb
-MACHINE_EMULATOR_TOOLS_IMAGE   := cartesi/machine-emulator-tools:$(MACHINE_EMULATOR_TOOLS_VERSION)
+TOOLS_DEB     := machine-emulator-tools-v$(VERSION).deb
+TOOLS_IMAGE   := cartesi/machine-emulator-tools:$(VERSION)
 
 LINUX_SOURCES_VERSION  ?= 6.5.9-ctsi-1
 LINUX_SOURCES_URLPATH  := https://github.com/cartesi/linux/archive/refs/tags/v$(LINUX_SOURCES_VERSION).tar.gz
 
-all: $(MACHINE_EMULATOR_TOOLS_DEB)
+all: $(TOOLS_DEB)
 
 build: Dockerfile control
-	docker buildx build --platform=linux/riscv64 --load \
-		--build-arg MACHINE_EMULATOR_TOOLS_DEB=$(MACHINE_EMULATOR_TOOLS_DEB) \
+	@docker buildx build --platform=linux/riscv64 --load \
+		--build-arg MACHINE_EMULATOR_TOOLS_DEB=$(TOOLS_DEB) \
 		--build-arg LINUX_SOURCES_VERSION=$(LINUX_SOURCES_VERSION) \
 		--build-arg LINUX_SOURCES_URLPATH=$(LINUX_SOURCES_URLPATH) \
-		-t $(MACHINE_EMULATOR_TOOLS_IMAGE) \
+		-t $(TOOLS_IMAGE) \
 		-f $< \
 		.
 
 copy:
-	ID=`docker create --platform=linux/riscv64 $(MACHINE_EMULATOR_TOOLS_IMAGE)` && \
-	   docker cp $$ID:/opt/cartesi/$(MACHINE_EMULATOR_TOOLS_DEB)    . && \
+	@ID=`docker create --platform=linux/riscv64 $(TOOLS_IMAGE)` && \
+	   docker cp $$ID:/opt/cartesi/$(TOOLS_DEB)    . && \
 	   docker rm $$ID
 
 control:
-	sed 's|ARG_VERSION|$(VERSION)|g' control.template > control
+	@sed 's|ARG_VERSION|$(VERSION)|g' control.template > control
 
-$(MACHINE_EMULATOR_TOOLS_DEB): build copy
+$(TOOLS_DEB) deb: build copy
 
-fs: $(MACHINE_EMULATOR_TOOLS_DEB)
+rootfs.ext2: $(TOOLS_DEB)
+	@docker buildx build --platform=linux/riscv64 --load \
+	  --build-arg TOOLS=$(TOOLS_DEB) \
+	  --output type=tar,dest=rootfs.tar \
+	  --file fs.Dockerfile \
+	  . && \
+	bsdtar -cf rootfs.gnutar --format=gnutar @rootfs.tar && \
+	xgenext2fs -fzB 4096 -i 4096 -a rootfs.gnutar -L rootfs rootfs.ext2
+
+fs: rootfs.ext2
 
 env:
-	@echo MACHINE_EMULATOR_TOOLS_DEB=$(MACHINE_EMULATOR_TOOLS_DEB)
-	@echo MACHINE_EMULATOR_TOOLS_VERSION=$(MACHINE_EMULATOR_TOOLS_VERSION)
+	@echo TOOLS_DEB=$(TOOLS_DEB)
 	@echo LINUX_SOURCES_VERSION=$(LINUX_SOURCES_VERSION)
 	@echo LINUX_SOURCES_URLPATH=$(LINUX_SOURCES_URLPATH)
 
 setup:
-	docker run --privileged --rm  linuxkit/binfmt:bebbae0c1100ebf7bf2ad4dfb9dfd719cf0ef132
+	@docker run --privileged --rm  linuxkit/binfmt:bebbae0c1100ebf7bf2ad4dfb9dfd719cf0ef132
 
 setup-required:
 	@echo 'riscv64 buildx setup required:' `docker buildx ls | grep -q riscv64 && echo no || echo yes`
 
 help:
 	@echo 'available commands:'
+	@echo '  deb             - build machine-emulator-tools .deb package'
+	@echo '  fs              - build rootfs.ext2'
 	@echo '  setup           - setup riscv64 buildx'
 	@echo '  setup-required  - check if riscv64 buildx setup is required'
 	@echo '  help            - list makefile commands'
@@ -72,6 +81,6 @@ help:
 	@echo '  distclean       - clean and remove dependencies'
 
 clean:
-	rm -f $(MACHINE_EMULATOR_TOOLS_DEB) control
+	rm -f $(TOOLS_DEB) control rootfs.*
 
 .PHONY: build copy fs env setup setup-required help distclean
diff --git a/example/README.md b/example/README.md
deleted file mode 100644
index 98e322df..00000000
--- a/example/README.md
+++ /dev/null
@@ -1,39 +0,0 @@
-# Example: Cartesi root filesystem with machine emulator tools
-
-The following example demonstrates how to create a bootable root filesystem for the Cartesi Machine based on a Ubuntu RISC-V 64 docker image. It requires the machine-emulator-tools.
-
-### Requirements
-
-- Docker >= 18.x
-- GNU Make >= 3.81
-- xgenext2fs >= 1.5.3
-- bsdtar >= 3.6.2
-- bc >= 1.06
-
-### Building
-
-```sh
-cp ../machine-emulator-tools-v0.13.0.tar.gz .
-./build ubuntu-22.04.dockerfile
-```
-
-After the build is done, the file `ubuntu-22.04.ext2` should be available in the current path.
-Assuming you have `cartesi-machine` installed in your environment,
-you can then test interactive terminal with it:
-
-```sh
-$ cartesi-machine --flash-drive=label:root,filename:ubuntu-22.04.ext2 -i bash
-Running in interactive mode!
-
-         .
-        / \
-      /    \
-\---/---\  /----\
- \       X       \
-  \----/  \---/---\
-       \    / CARTESI
-        \ /   MACHINE
-         '
-
-root@cartesi-machine:~#
-```
diff --git a/example/build b/example/build
deleted file mode 100755
index edd2b8bd..00000000
--- a/example/build
+++ /dev/null
@@ -1,32 +0,0 @@
-#!/bin/sh
-
-set -e
-
-if [ $# -eq 0 ]; then
-  echo "no dockerfile supplied"
-  exit 1
-fi
-
-NAME=${1%.*}
-DOCKERFILE="$NAME.dockerfile"
-TOOLS=machine-emulator-tools-v0.13.0.tar.gz
-
-if [ ! -f "$DOCKERFILE" ]; then
-  echo "dockerfile \"$DOCKERFILE\" not found"
-  exit 1
-fi
-
-if [ ! -f "$TOOLS" ]; then
-  echo "tools tarball \"$TOOLS\" not found"
-  exit 1
-fi
-
-TAR=$(mktemp) && \
-docker buildx build --progress plain \
-  --build-arg TOOLS=$TOOLS \
-  --output type=tar,dest=$TAR \
-  --file $NAME.dockerfile \
-  . && \
-GNUTAR=$(mktemp) && \
-bsdtar -cf $GNUTAR --format=gnutar @$TAR
-./img-pack $GNUTAR $NAME.ext2 rootfs && (rm -f $TAR $GNUTAR; echo "created $NAME.ext2"; true) || (rm -f $TAR $GNUTAR; false)
diff --git a/example/img-pack b/example/img-pack
deleted file mode 100755
index feeed659..00000000
--- a/example/img-pack
+++ /dev/null
@@ -1,17 +0,0 @@
-#!/bin/sh
-blocksize=4096
-bytes=$(($(wc -c < "$1") +0))
-bcargs="$(cat <<- EOF
-	define max(a, b) { return (a > b) * a + (a <= b) * b }
-	max(8, 1.5 * ($bytes + $blocksize - 1) / $blocksize)
-	EOF
-)"
-blocks=$(echo "$bcargs" | bc)
-
-xgenext2fs \
-	-fzB $blocksize \
-	-b   $blocks \
-	-i   $blocksize \
-	-L   ${3:-rootfs} \
-	-a   $1 \
-	$2
diff --git a/example/ubuntu-22.04.dockerfile b/example/ubuntu-22.04.dockerfile
deleted file mode 100644
index 10ecd658..00000000
--- a/example/ubuntu-22.04.dockerfile
+++ /dev/null
@@ -1,9 +0,0 @@
-FROM --platform=linux/riscv64 riscv64/ubuntu:22.04
-ARG TOOLS=machine-emulator-tools.tar.gz
-RUN apt-get update && \
-    apt-get install -y --no-install-recommends \
-      busybox-static \
-      python3 python3-requests && \
-    rm -rf /var/lib/apt/lists/*
-RUN useradd --create-home --user-group dapp
-ADD ${TOOLS} /
diff --git a/fs.Dockerfile b/fs.Dockerfile
new file mode 100644
index 00000000..42c9f035
--- /dev/null
+++ b/fs.Dockerfile
@@ -0,0 +1,14 @@
+FROM --platform=linux/riscv64 riscv64/ubuntu:22.04
+ARG TOOLS_DEB=machine-emulator-tools-v0.14.0.deb
+ADD ${TOOLS_DEB} /tmp/
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+      busybox-static=1:1.30.1-7ubuntu3 \
+      ca-certificates=20230311ubuntu0.22.04.1 \
+      curl=7.81.0-1ubuntu1.14 \
+      /tmp/${TOOLS_DEB} \
+      python3 \
+      python3-requests && \
+    rm -rf /tmp/${TOOLS_DEB} && \
+    rm -rf /var/lib/apt/lists/*
+RUN useradd --create-home --user-group dapp