diff --git a/.dockerignore b/.dockerignore
index 189900848..4e945137a 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -1,14 +1,17 @@
 # Ignore non-build related directories
-/.git/
 /doc/
 /sample/
 /vstudio/
+/.*/
 
+#prebuilds
+/lib/
+/out/
+/bin/
 # Ignore non-build related files
-/.dockerignore
-/.gitignore
-/build_adv.bat
-/build_lib.bat
+.*
+.DS_Store
+/*.bat
 /changelog.txt
 /COPYING.RUNTIME
 /Dockerfile
diff --git a/.github/workflows/sgdk-docker.yml b/.github/workflows/sgdk-docker.yml
new file mode 100644
index 000000000..2747e43ca
--- /dev/null
+++ b/.github/workflows/sgdk-docker.yml
@@ -0,0 +1,107 @@
+name: sgdk-docker
+
+concurrency:
+  group: ${{ github.ref }}-sgdk-docker
+  cancel-in-progress: true
+
+on:
+  workflow_dispatch: # Allows for manual triggering.
+  pull_request: # Trigger for pull requests.
+    types: [opened, synchronize, reopened, ready_for_review]
+    branches:
+      - master
+  push: # Trigger when pushed to master.
+    branches:
+      - 'master'
+    paths-ignore:
+      - 'vstudio/**'
+      - 'bin/**'
+      - 'sample/**'
+      - '**.md'
+
+env:
+  # TODO: arm64 images are currently disabled because they keep hanging in the
+  # GitHub Actions environment.
+  #PLATFORMS: linux/amd64,linux/arm64
+  PLATFORMS: linux/amd64
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    permissions:
+      packages: write
+      contents: read
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      # TODO: arm64 images are currently disabled because they keep hanging in
+      # the GitHub Actions environment.
+      #- name: Set up QEMU
+      #  uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to GHCR (only on push event)
+        if: github.event_name == 'push'
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Check if GCC Dockerfile has changed
+        id: changed-files
+        uses: tj-actions/changed-files@v42
+        with:
+          files_yaml: |
+            gcc:
+              - deps/gcc.Dockerfile
+
+      - name: Build m68k GCC (only if changed)
+        if: steps.changed-files.outputs.gcc_any_changed == 'true'
+        uses: docker/build-push-action@v5
+        with:
+          file: deps/gcc.Dockerfile
+          context: deps/
+          platforms: ${{ env.PLATFORMS }}
+          tags: ghcr.io/${{ github.actor }}/sgdk-m68k-gcc:latest
+          push: false
+          load: true
+
+      # Push is a separate step so the build logs are clearly separate from the
+      # push logs.
+      - name: Push m68k GCC (only if changed, only on push event)
+        if: steps.changed-files.outputs.gcc_any_changed == 'true' && github.event_name == 'push'
+        run: |
+          docker image push ghcr.io/${{ github.actor }}/sgdk-m68k-gcc:latest
+
+      # NOTE: If you are seeing failures in this job right after forking SGDK,
+      # you may need to bootstrap the base image into your fork on ghcr.io.
+      # This can be done with:
+      #   docker image pull ghcr.io/stephane-d/sgdk-m68k-gcc:latest
+      #   docker image tag ghcr.io/stephane-d/sgdk-m68k-gcc:latest \
+      #                    ghcr.io/YOUR_NAMEE/sgdk-m68k-gcc:latest
+      #   gh auth token | docker login ghcr.io -u YOUR_NAME --password-stdin
+      #   docker image push ghcr.io/YOUR_NAMEE/sgdk-m68k-gcc:latest
+      - name: Build SGDK
+        uses: docker/build-push-action@v5
+        with:
+          file: Dockerfile
+          context: .
+          platforms: ${{ env.PLATFORMS }}
+          build-args: |
+            BASE_IMAGE=ghcr.io/${{ github.actor }}/sgdk-m68k-gcc
+          tags: ghcr.io/${{ github.actor }}/sgdk:latest
+          push: false
+          load: true
+
+      # Push is a separate step so the build logs are clearly separate from the
+      # push logs.
+      - name: Push SGDK (only on push event)
+        if: github.event_name == 'push'
+        run: |
+          docker image push ghcr.io/${{ github.actor }}/sgdk:latest
diff --git a/.gitignore b/.gitignore
index 21fae20c0..d24331a20 100644
--- a/.gitignore
+++ b/.gitignore
@@ -45,3 +45,5 @@ tools/rescomp/format
 tools/rescomp/rescomp.jar
 tools/xgm rom builder/bin
 src/z80_*.h
+/.idea
+*.iml
diff --git a/Dockerfile b/Dockerfile
index 6c2b4e58b..63c46603d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,36 +1,117 @@
-FROM amd64/ubuntu:20.04
-
-# Set-up argument defaults
+ARG ALPINE_VERSION=3.18.3
 ARG JDK_VER=11
 
-# Install supporting packages
-RUN dpkg --add-architecture i386 \
-  && apt-get update  \
-  && DEBIAN_FRONTEND=noninteractive apt-get install -y \
-  bash \
-  make \
-  openjdk-${JDK_VER}-jre-headless \
-  wine32 \
-  && rm -rf /var/lib/apt/lists/*
+ARG BASE_IMAGE=ghcr.io/stephane-d/sgdk-m68k-gcc
+ARG BASE_IMAGE_VERSION=latest
 
-# Create sgdk unprivileged user
-RUN useradd -ms /bin/sh -d /sgdk sgdk
+# Stage Zero - just init image to download files in other stages
+FROM $BASE_IMAGE:$BASE_IMAGE_VERSION as m68k-files
+
+
+FROM alpine:$ALPINE_VERSION as jdk-base
+ARG JDK_VER
+RUN apk add --no-cache openjdk${JDK_VER}
+
+
+
+# Stage One - build all tools and libs for SGDK
+FROM jdk-base as build
+RUN apk add --no-cache build-base git
 
 # Set-up SGDK
-COPY . /sgdk
-ENV GDK=/sgdk
-ENV SGDK_DOCKER=y
+WORKDIR /sgdk
+COPY . .
+ENV SGDK_PATH=/sgdk
+RUN mkdir -p $SGDK_PATH/bin
+
+# Building sjasm
+ENV SJASMEP_DIR="/tmp/sjasmep"
+RUN git clone https://github.com/istvan-v/sjasmep.git $SJASMEP_DIR
+WORKDIR $SJASMEP_DIR
+RUN make
+RUN mv $SJASMEP_DIR/sjasm $SGDK_PATH/bin/
+
+# Building bintos
+WORKDIR $SGDK_PATH/tools/bintos
+RUN gcc -O2 -s src/bintos.c -o $SGDK_PATH/bin/bintos
+
+# Building xgmtool
+WORKDIR $SGDK_PATH/tools/xgmtool
+RUN gcc -fexpensive-optimizations -Os -s src/*.c -o $SGDK_PATH/bin/xgmtool
+
+# Building apj.jar
+WORKDIR $SGDK_PATH/tools/apj/src
+RUN javac sgdk/aplib/*.java
+RUN jar cfe $SGDK_PATH/bin/apj.jar sgdk.aplib.Launcher sgdk/aplib/*.class
+
+# Building lz4w.jar
+WORKDIR $SGDK_PATH/tools/lz4w/src
+RUN javac sgdk/lz4w/*.java
+RUN jar cfe $SGDK_PATH/bin/lz4w.jar sgdk.lz4w.Launcher sgdk/lz4w/*.class
+
+# Building sizebnd.jar
+WORKDIR $SGDK_PATH/tools/sizebnd/src
+RUN javac sgdk/sizebnd/*.java
+RUN jar cfe $SGDK_PATH/bin/sizebnd.jar sgdk.sizebnd.Launcher sgdk/sizebnd/*.class
+
+# Building rescomp.jar
+WORKDIR $SGDK_PATH/tools/rescomp/src
+ENV CLASSPATH="$SGDK_PATH/bin/apj.jar:$SGDK_PATH/bin/lz4w.jar:$SGDK_PATH/tools/rescomp/src"
+RUN cp -r $SGDK_PATH/tools/commons/src/sgdk .
+RUN find . -name "*.java"
+RUN find . -name "*.java" | xargs javac
+RUN echo -e "Main-Class: sgdk.rescomp.Launcher\nClass-Path: apj.jar lz4w.jar" > Manifest.txt
+RUN jar cfm $SGDK_PATH/bin/rescomp.jar Manifest.txt  .
+
+COPY --from=m68k-files /m68k/ /usr/
+ENV PATH="$SGDK_PATH/bin:${PATH}"
 
-# Create wrappers to execute .exe files using wine
-RUN sed -i 's/\r$//' sgdk/bin/create-bin-wrappers.sh && \  
-        chmod +x sgdk/bin/create-bin-wrappers.sh
-        
-RUN sgdk/bin/create-bin-wrappers.sh
+WORKDIR $SGDK_PATH
+RUN mkdir lib
+#build libmd.a
+RUN make -f makelib.gen release
+#build libmd_debug.a
+RUN make -f makelib.gen debug
+RUN rm -rf $SGDK_PATH/tools
+
+
+
+FROM jdk-base as jre-minimal
+ENV JRE_MODULES="java.base,java.desktop,java.xml"
+RUN jlink \
+    --module-path "$JAVA_HOME/jmods" \
+    --add-modules $JRE_MODULES \
+    --verbose \
+    --strip-debug \
+    --compress 2 \
+    --no-header-files \
+    --no-man-pages \
+    --output /opt/jre-minimal
+
+
+### Second Stage - clean image ###
+FROM alpine:$ALPINE_VERSION
+RUN apk add --no-cache build-base
+
+COPY --from=m68k-files /m68k/ /usr/
+
+COPY --from=jre-minimal /opt/jre-minimal /opt/jre-minimal
+ENV JAVA_HOME=/opt/jre-minimal
+ENV PATH="$PATH:$JAVA_HOME/bin"
+
+# Set-up SGDK
+ENV SGDK_PATH=/sgdk
+
+# Create sgdk unprivileged user
+RUN addgroup -S sgdk && adduser -S sgdk -G sgdk -h $SGDK_PATH
+
+COPY --from=build --chown=sgdk:sgdk $SGDK_PATH $SGDK_PATH
+
+ENV PATH="$SGDK_PATH/bin:${PATH}"
 
 # Set-up mount point and make command
 VOLUME /src
 WORKDIR /src
-
 # Use sgdk user
 USER sgdk
-ENTRYPOINT [ "make", "-f", "/sgdk/makefile.gen" ]
+ENTRYPOINT ["/bin/sh","-c","make -f $SGDK_PATH/makefile.gen $@", "--"]
diff --git a/Dockerfile-m1 b/Dockerfile-m1
deleted file mode 100644
index 903d221c4..000000000
--- a/Dockerfile-m1
+++ /dev/null
@@ -1,59 +0,0 @@
-FROM ubuntu:latest
-
-# Set-up argument defaults
-ARG JDK_VER=11
-
-# Install supporting packages
-RUN apt-get update  \
-  && DEBIAN_FRONTEND=noninteractive apt-get install -y \
-  bash \
-  make \
-  git \
-  babeltrace \
-  rsync \
-  bison gcc g++ lhasa libgmp-dev libmpfr-dev libmpc-dev flex gettext texinfo \
-  openjdk-${JDK_VER}-jre-headless \
-  && rm -rf /var/lib/apt/lists/*
-
-# install GCC 6.3
-
-RUN cd /opt \
-    && curl -O http://barelyconsciousgames.com/m68k-toolchain-rpi.tar.gz \
-    && tar xvzf m68k-toolchain-rpi.tar.gz \
-    && apt-get update \
-    && DEBIAN_FRONTEND=noninteractive apt-get install -y libc6-armhf-cross \
-    && ln -s /usr/arm-linux-gnueabihf/lib/ld-linux-armhf.so.3 /lib/ \
-    && ln -s /usr/arm-linux-gnueabihf/lib/libm.so.6 /lib \
-    && ln -s /usr/arm-linux-gnueabihf/lib/libc.so.6 /lib \
-    && ln -s /usr/arm-linux-gnueabihf/lib/libdl.so.2 /lib \
-    && rm m68k-toolchain-rpi.tar.gz
-
-# Create sgdk unprivileged user
-RUN useradd -ms /bin/sh -d /sgdk sgdk
-
-# Set-up SGDK
-COPY . /sgdk
-ENV GDK=/sgdk
-ENV SGDK_DOCKER=n
-
-RUN cd /tmp \
-    && git clone https://github.com/istvan-v/sjasmep.git \
-    && cd sjasmep \
-    && make \
-    && mv sjasm /sgdk/bin
-
-ENV PATH="/opt/m68k-toolchain/bin:/sgdk/bin:${PATH}" 
-
-RUN cd /sgdk/tools/bintos \
-    && gcc -O2 -s src/bintos.c -o ../../bin/bintos
-
-RUN cd /sgdk/tools/xgmtool \
-    && gcc -fexpensive-optimizations -Os -s src/*.c -o ../../bin/xgmtool
-
-# Set-up mount point and make command
-VOLUME /src
-WORKDIR /src
-
-# Use sgdk user
-USER sgdk
-ENTRYPOINT [ "make", "-f", "/sgdk/makefile.gen" ]
diff --git a/bin/create-bin-wrappers.sh b/bin/create-bin-wrappers.sh
deleted file mode 100755
index 43677e90d..000000000
--- a/bin/create-bin-wrappers.sh
+++ /dev/null
@@ -1,17 +0,0 @@
-#!/bin/bash
-
-# This script will be executed at docker build.
-# See Dockerfile
-
-BIN_PATH="/sgdk/bin"
-
-# Create a bash script for each .exe file in BIN_PATH
-for binary in $BIN_PATH/*.exe; do
-    BASENAME=$(basename $binary .exe)
-    FILENAME=$BIN_PATH/$BASENAME
-    echo "#!/bin/bash" > $FILENAME
-    # create a wineconf folder owned by us, otherwise it will refuse to execute for current user
-    echo "mkdir -p /tmp/wine" >> $FILENAME
-    echo "WINEARCH=win32 WINEDEBUG=-all WINEPREFIX=/tmp/wine/.wineconf wine /sgdk/bin/$BASENAME.exe \"\$@\"" >> $FILENAME
-    chmod +x $FILENAME
-done
diff --git a/common.mk b/common.mk
index dcac4b9ca..5e041182a 100644
--- a/common.mk
+++ b/common.mk
@@ -27,42 +27,23 @@ ifeq ($(OS),Windows_NT)
 	LTO_PLUGIN := --plugin=liblto_plugin-0.dll
 	LIBGCC := $(LIB)/libgcc.a
 else
-	ifeq ($(SGDK_DOCKER),y)
-		# Linux docker
-		SHELL = sh
-		RM = rm
-		CP = cp
-		MKDIR = mkdir
+	# Native Linux and Docker
+	PREFIX ?= m68k-elf-
+	SHELL = sh
+	RM = rm
+	CP = cp
+	MKDIR = mkdir
 
-		AR := $(BIN)/ar
-		CC := $(BIN)/gcc
-		LD := $(BIN)/ld
-		NM := $(BIN)/nm
-		OBJCPY := $(BIN)/objcopy
-		ASMZ80 := $(BIN)/sjasm
-		MACCER := $(BIN)/mac68k
-		BINTOS := $(BIN)/bintos
-		LTO_PLUGIN := --plugin=liblto_plugin-0.dll
-		LIBGCC := $(LIB)/libgcc.a
-	else
-		# Native Linux
-		PREFIX ?= m68k-elf-
-		SHELL = sh
-		RM = rm
-		CP = cp
-		MKDIR = mkdir
-
-		AR := $(PREFIX)ar
-		CC := $(PREFIX)gcc
-		LD := $(PREFIX)ld
-		NM := $(PREFIX)nm
-		OBJCPY := $(PREFIX)objcopy
-		ASMZ80 := sjasm
-		MACCER := mac68k
-		BINTOS := bintos
-	    LTO_PLUGIN :=
-		LIBGCC := -lgcc
-	endif
+	AR := $(PREFIX)ar
+	CC := $(PREFIX)gcc
+	LD := $(PREFIX)ld
+	NM := $(PREFIX)nm
+	OBJCPY := $(PREFIX)objcopy
+	ASMZ80 := sjasm
+	MACCER := mac68k
+	BINTOS := bintos
+	LTO_PLUGIN :=
+	LIBGCC := -lgcc
 endif
 
 JAVA := java
diff --git a/deps/gcc.Dockerfile b/deps/gcc.Dockerfile
new file mode 100644
index 000000000..28299e772
--- /dev/null
+++ b/deps/gcc.Dockerfile
@@ -0,0 +1,151 @@
+ARG ALPINE_VERSION=3.18.3
+
+ARG BASEDIR=/tmp/work
+
+FROM alpine:$ALPINE_VERSION as build
+ARG BASEDIR
+ARG _binu_ver=2.37
+ARG _gcc_ver=6.3.0
+ARG _mpfrver=4.1.0
+ARG _mpcver=1.2.1
+ARG _gmpver=6.2.1
+ARG _newlib_ver=4.1.0
+ARG PARALLEL_BUILD=1
+
+ENV TARGET=m68k-elf
+ENV TARGET_CPU=m68000
+
+ENV BASEDIR=$BASEDIR
+ENV BINUTILS=binutils-${_binu_ver}
+ENV GCC=gcc-${_gcc_ver}
+ENV MPFR=mpfr-${_mpfrver}
+ENV MPC=mpc-${_mpcver}
+ENV GMP=gmp-${_gmpver}
+ENV NEWLIB=newlib-${_newlib_ver}
+
+ENV SRCDIR="$BASEDIR/src"
+ENV BUILDDIR="$BASEDIR/build"
+ENV INSTALLDIR="$BASEDIR/install"
+ENV STAGINGDIR="$BASEDIR/staging"
+ENV PARALLEL_BUILD="$PARALLEL_BUILD"
+
+# Choose parallel build or not.  Parallel builds can cause issues with
+# low-memory hosts or emulation.  If parallel builds are disabled, replace
+# nproc so it always says "1".
+RUN echo "nproc = $(nproc)"
+RUN echo "PARALLEL_BUILD = $PARALLEL_BUILD"
+RUN if [[ "$PARALLEL_BUILD" == 0 ]]; then echo -e "#!/bin/sh\necho 1" > /usr/local/bin/nproc; chmod 755 /usr/local/bin/nproc; fi
+RUN echo "which nproc = $(which nproc)"
+
+RUN mkdir -p "$SRCDIR"
+RUN mkdir -p "$BUILDDIR"
+RUN mkdir -p "$INSTALLDIR"
+RUN mkdir -p "$STAGINGDIR"
+
+WORKDIR $SRCDIR
+RUN wget http://ftp.gnu.org/gnu/binutils/${BINUTILS}.tar.xz -O - | tar -xJ
+RUN wget http://ftp.gnu.org/gnu/gcc/${GCC}/${GCC}.tar.bz2  -O - | tar -xj
+RUN wget http://ftp.gnu.org/gnu/mpfr/${MPFR}.tar.xz  -O - | tar -xJ
+RUN wget http://ftp.gnu.org/gnu/mpc/${MPC}.tar.gz  -O - | tar -xz
+RUN wget http://ftp.gnu.org/gnu/gmp/${GMP}.tar.xz  -O - | tar -xJ
+RUN wget ftp://sourceware.org/pub/newlib/${NEWLIB}.tar.gz  -O - | tar -xz
+
+RUN apk add --no-cache bash build-base zlib-dev
+
+#################################################################################
+##########################    Building binutils    ##############################
+#################################################################################
+WORKDIR $BUILDDIR/$BINUTILS
+RUN $SRCDIR/$BINUTILS/configure \
+	--prefix=/usr \
+	--target=$TARGET \
+	--disable-multilib \
+	--with-cpu=$TARGET_CPU \
+	--disable-nls
+
+RUN make -j"$(nproc)"
+RUN make prefix=$INSTALLDIR/$BINUTILS/usr install
+RUN rm -rf $INSTALLDIR/$BINUTILS/usr/share
+RUN rm $INSTALLDIR/$BINUTILS/usr/lib/bfd-plugins/libdep.so
+RUN cp -r $INSTALLDIR/$BINUTILS/usr/ $STAGINGDIR
+RUN cp -r $INSTALLDIR/$BINUTILS/usr/* /usr/
+#################################################################################
+#########################    Building GCC bootstrap    ##########################
+#################################################################################
+WORKDIR $SRCDIR/$GCC
+RUN ln -fs ../$MPFR mpfr
+RUN ln -fs ../$MPC mpc
+RUN ln -fs ../$GMP gmp
+
+WORKDIR $BUILDDIR/$GCC-bootstrap
+# These flags are required to build older versions of GCC
+ENV CFLAGS="$CFLAGS -Wno-implicit-fallthrough -Wno-cast-function-type -fpermissive"
+ENV CXXFLAGS="$CXXFLAGS -Wno-implicit-fallthrough -Wno-cast-function-type -fpermissive"
+RUN $SRCDIR/$GCC/configure \
+	--prefix=/usr \
+	--target=$TARGET \
+	--enable-languages="c" \
+	--disable-multilib \
+	--with-cpu=$TARGET_CPU \
+	--with-system-zlib \
+	--with-libgloss \
+	--without-headers \
+	--disable-shared \
+	--disable-nls
+
+RUN make -j"$(nproc)" all-gcc
+RUN make DESTDIR="$INSTALLDIR/$GCC-bootstrap" install-strip-gcc
+RUN rm -rf "$INSTALLDIR/$GCC-bootstrap/usr/share"
+RUN cp -r "$INSTALLDIR/$GCC-bootstrap/usr/"* /usr/
+#################################################################################
+#############################    Building NewLib    #############################
+#################################################################################
+WORKDIR $BUILDDIR/$NEWLIB
+ENV CFLAGS_FOR_TARGET="-Os -g -ffunction-sections -fdata-sections -fomit-frame-pointer -ffast-math"
+
+RUN "$SRCDIR/$NEWLIB/configure" \
+	--prefix=/usr \
+	--target=$TARGET \
+	--enable-languages="c" \
+	--disable-newlib-supplied-syscalls \
+	--disable-multilib \
+	--with-cpu=$TARGET_CPU \
+	--disable-nls
+
+RUN make -j"$(nproc)"
+RUN DESTDIR=$INSTALLDIR/$NEWLIB make install
+RUN cp -r "$INSTALLDIR/$NEWLIB/usr/" "$STAGINGDIR"
+RUN cp -r "$INSTALLDIR/$NEWLIB/usr/"* /usr/
+ENV CFLAGS_FOR_TARGET=""
+#################################################################################
+############################    Building final GCC    ###########################
+#################################################################################
+WORKDIR $BUILDDIR/$GCC
+
+RUN "$SRCDIR/$GCC/configure" \
+	--prefix=/usr \
+	--target=$TARGET \
+	--enable-languages="c,c++" \
+	--disable-multilib \
+	--with-cpu=$TARGET_CPU \
+	--with-system-zlib \
+	--with-newlib \
+	--with-libgloss \
+	--disable-shared \
+	--disable-nls
+
+RUN make -j"$(nproc)"
+RUN make DESTDIR="$INSTALLDIR/$GCC" install-strip
+RUN rm -rf "$INSTALLDIR/$GCC/usr/share"
+RUN rm "$INSTALLDIR/$GCC/usr/lib/libcc1.so"
+RUN rm "$INSTALLDIR/$GCC/usr/lib/libcc1.so.0"
+RUN rm "$INSTALLDIR/$GCC/usr/lib/libcc1.so.0.0.0"
+
+RUN cp -ar "$INSTALLDIR/$GCC/usr/" "$STAGINGDIR"
+
+
+# Second stage, just copy the built files
+FROM scratch
+ARG BASEDIR
+WORKDIR /m68k
+COPY --from=build $BASEDIR/staging/usr/ ./
diff --git a/makefile.gen b/makefile.gen
index 1f4bcafe7..051fea54d 100644
--- a/makefile.gen
+++ b/makefile.gen
@@ -10,18 +10,20 @@ include $(GDK)/common.mk
 SRC := src
 RES := res
 INCLUDE := inc
-
+OUT := out
 
 SRC_C= $(wildcard *.c)
 SRC_C+= $(wildcard $(SRC)/*.c)
 SRC_C+= $(wildcard $(SRC)/*/*.c)
 SRC_C+= $(wildcard $(SRC)/*/*/*.c)
 SRC_C:= $(filter-out $(SRC)/boot/rom_head.c,$(SRC_C))
+ifeq ($(SRC_C),)
+SRC_C=$(SRC)/main.c
+endif
 SRC_S= $(wildcard *.s)
 SRC_S+= $(wildcard $(SRC)/*.s)
 SRC_S+= $(wildcard $(SRC)/*/*.s)
 SRC_S+= $(wildcard $(SRC)/*/*/*.s)
-SRC_S:= $(filter-out $(SRC)/boot/sega.s,$(SRC_S))
 SRC_ASM= $(wildcard *.asm)
 SRC_ASM+= $(wildcard $(SRC)/*.asm)
 SRC_ASM+= $(wildcard $(SRC)/*/*.asm)
@@ -39,7 +41,7 @@ RES_RES+= $(wildcard $(RES)/*.res)
 RES_RS= $(RES_RES:.res=.rs)
 RES_H= $(RES_RES:.res=.h)
 RES_DEP= $(RES_RES:.res=.d)
-RES_DEPS= $(addprefix out/, $(RES_DEP))
+RES_DEPS= $(addprefix $(OUT)/, $(RES_DEP))
 
 OBJ= $(RES_RES:.res=.o)
 OBJ+= $(RES_S:.s=.o)
@@ -48,14 +50,14 @@ OBJ+= $(SRC_S80:.s80=.o)
 OBJ+= $(SRC_ASM:.asm=.o)
 OBJ+= $(SRC_S:.s=.o)
 OBJ+= $(SRC_C:.c=.o)
-OBJS:= $(addprefix out/, $(OBJ))
+OBJS:= $(addprefix $(OUT)/, $(OBJ))
 
 DEPS:= $(OBJS:.o=.d)
 
 #-include $(DEPS)
 
 LST:= $(SRC_C:.c=.lst)
-LSTS:= $(addprefix out/, $(LST))
+LSTS:= $(addprefix $(OUT)/, $(LST))
 
 INCS:= -I$(INCLUDE) -I$(SRC) -I$(RES) -I$(INCLUDE_LIB) -I$(RES_LIB)
 DEFAULT_FLAGS= $(EXTRA_FLAGS) -DSGDK_GCC -m68000 -Wall -Wextra -Wno-shift-negative-value -Wno-main -Wno-unused-parameter -fno-builtin -fms-extensions $(INCS) -B$(BIN)
@@ -66,20 +68,39 @@ release: FLAGS= $(DEFAULT_FLAGS) -O3 -fuse-linker-plugin -fno-web -fno-gcse -fno
 release: CFLAGS= $(FLAGS)
 release: AFLAGS= $(FLAGS)
 release: LIBMD= $(LIB)/libmd.a
-release: pre-build out/rom.bin out/symbol.txt
+release: $(OUT)/rom.bin $(OUT)/symbol.txt
+.PHONY: release
+
 #release: $(info $$var is [${SRC_C}])
 
 debug: FLAGS= $(DEFAULT_FLAGS) -O1 -DDEBUG=1
 debug: CFLAGS= $(FLAGS) -ggdb
 debug: AFLAGS= $(FLAGS)
 debug: LIBMD= $(LIB)/libmd_debug.a
-debug: pre-build out/rom.bin out/rom.out out/symbol.txt
+debug: $(OUT)/rom.bin $(OUT)/rom.out $(OUT)/symbol.txt
+.PHONY: debug
 
 asm: FLAGS= $(DEFAULT_FLAGS) -O3 -fuse-linker-plugin -fno-web -fno-gcse -fno-unit-at-a-time -fomit-frame-pointer -S
 asm: CFLAGS= $(FLAGS)
 asm: AFLAGS= $(FLAGS)
 asm: LIBMD= $(LIB)/libmd.a
-asm: pre-build $(LSTS)
+asm: $(LSTS)
+.PHONY: asm
+
+define MAIN_C_CONTENT
+#include "genesis.h"
+
+int main(bool hardReset){
+    VDP_drawText("Hello SGDK!", 12, 12);
+    while(TRUE) { SYS_doVBlankProcess(); }
+    return 0;
+}
+endef
+
+$(SRC)/main.c: export MAIN_C_CONTENT:=$(MAIN_C_CONTENT)
+$(SRC)/main.c:
+	$(MKDIR) -p $(dir $@)
+	$(ECHO) "$${MAIN_C_CONTENT}" > $@
 
 # include ext.mk if it exists (better to do it after release rule definition)
 ifneq ("$(wildcard $(GDK)/ext.mk)","")
@@ -94,94 +115,104 @@ Debug: debug
 Release: release
 Asm: asm
 
-.PHONY: clean
-
 cleantmp:
 	$(RM) -f $(RES_RS)
+.PHONY: cleantmp
 
 cleandep:
 	$(RM) -f $(DEPS)
+.PHONY: cleandep
 
 cleanlst:
 	$(RM) -f $(LSTS)
+.PHONY: cleanlst
 
 cleanres: cleantmp
 	$(RM) -f $(RES_H) $(RES_DEP) $(RES_DEPS)
+.PHONY: cleanres
 
 cleanobj:
-	$(RM) -f $(OBJS) out/sega.o out/rom_head.bin out/rom_head.o out/rom.out
+	$(RM) -f $(OBJS) $(OUT)/sega.o $(OUT)/rom_head.bin $(OUT)/rom_head.o $(OUT)/rom.out
+.PHONY: cleanobj
 
 clean: cleanobj cleanres cleanlst cleandep
-	$(RM) -f out.lst out/cmd_ out/symbol.txt out/rom.nm out/rom.wch out/rom.bin
+	$(RM) -f out.lst $(OUT)/cmd_ $(OUT)/symbol.txt $(OUT)/rom.nm $(OUT)/rom.wch $(OUT)/rom.bin
+.PHONY: clean
 
 cleanrelease: clean
+.PHONY: cleanrelease
 
 cleandebug: clean
+.PHONY: cleandebug
 
 cleanasm: cleanlst
+.PHONY: cleanasm
 
 cleandefault: clean
 cleanDefault: clean
+.PHONY: cleandefault cleanDefault
 
 cleanRelease: cleanrelease
 cleanDebug: cleandebug
 cleanAsm: cleanasm
-
-pre-build:
-	$(MKDIR) -p $(SRC)/boot
-	$(MKDIR) -p out
+.PHONY: cleanRelease cleanDebug cleanAsm
 
 
-out/rom.bin: out/rom.out
-	$(OBJCPY) -O binary out/rom.out out/rom.bin
-	$(SIZEBND) out/rom.bin -sizealign 131072 -checksum
+$(OUT)/rom.bin: $(OUT)/rom.out
+	$(OBJCPY) -O binary $(OUT)/rom.out $(OUT)/rom.bin
+	$(SIZEBND) $(OUT)/rom.bin -sizealign 131072 -checksum
 
-out/symbol.txt: out/rom.out
-	$(NM) $(LTO_PLUGIN) -n out/rom.out > out/symbol.txt
+$(OUT)/symbol.txt: $(OUT)/rom.out
+	$(NM) $(LTO_PLUGIN) -n $(OUT)/rom.out > $(OUT)/symbol.txt
 
-out/rom.out: out/sega.o out/cmd_ $(LIBMD)
-	$(CC) -m68000 -B$(BIN) -n -T $(GDK)/md.ld -nostdlib out/sega.o @out/cmd_ $(LIBMD) $(LIBGCC) -o out/rom.out -Wl,--gc-sections -flto
-	$(RM) out/cmd_
+$(OUT)/rom.out: $(OUT)/sega.o $(OUT)/cmd_ $(LIBMD)
+	$(MKDIR) -p $(dir $@)
+	$(CC) -m68000 -B$(BIN) -n -T $(GDK)/md.ld -nostdlib $(OUT)/sega.o @$(OUT)/cmd_ $(LIBMD) $(LIBGCC) -o $(OUT)/rom.out -Wl,--gc-sections -flto
+	$(RM) $(OUT)/cmd_
 
-out/cmd_: $(OBJS)
-	$(ECHO) "$(OBJS)" > out/cmd_
+$(OUT)/cmd_: $(OBJS)
+	$(MKDIR) -p $(dir $@)
+	$(ECHO) "$(OBJS)" > $(OUT)/cmd_
 
-out/sega.o: $(SRC)/boot/sega.s out/rom_head.bin
-	$(CC) -x assembler-with-cpp -Wa,--register-prefix-optional,--bitwise-or $(AFLAGS) -c $(SRC)/boot/sega.s -o $@
+$(OUT)/sega.o: $(OUT)/boot/sega.s $(OUT)/rom_head.bin
+	$(CC) -x assembler-with-cpp -Wa,--register-prefix-optional,--bitwise-or $(AFLAGS) -c $(OUT)/boot/sega.s -o $@
 
-out/rom_head.bin: out/rom_head.o
+$(OUT)/rom_head.bin: $(OUT)/rom_head.o
 	$(OBJCPY) -O binary $< $@
 
-out/rom_head.o: $(SRC)/boot/rom_head.c
+$(OUT)/rom_head.o: $(SRC)/boot/rom_head.c
+	$(MKDIR) -p $(dir $@)
 	$(CC) $(DEFAULT_FLAGS) -c $< -o $@
 
-$(SRC)/boot/sega.s: $(SRC_LIB)/boot/sega.s
+$(OUT)/boot/sega.s: $(SRC_LIB)/boot/sega.s
+	$(ECHO) $@
+	$(MKDIR) -p $(dir $@)
 	$(CP) $< $@
 
 $(SRC)/boot/rom_head.c: $(SRC_LIB)/boot/rom_head.c
+	$(MKDIR) -p $(dir $@)
 	$(CP) $< $@
 
-
-out/%.lst: %.c
+$(OUT)/%.lst: %.c
 	$(MKDIR) -p $(dir $@)
 	$(CC) $(CFLAGS) -c $< -o $@
 
-out/%.o: %.c
+$(OUT)/%.o: %.c
 	$(MKDIR) -p $(dir $@)
 	$(CC) $(CFLAGS) -MMD -c $< -o $@
 
-out/%.o: %.s
+$(OUT)/%.o: %.s
 	$(MKDIR) -p $(dir $@)
 	$(CC) -x assembler-with-cpp -Wa,--register-prefix-optional,--bitwise-or $(AFLAGS) -MMD -c $< -o $@
 
-out/%.o: %.rs
+$(OUT)/%.o: %.rs
 	$(MKDIR) -p $(dir $@)
 	$(CC) -x assembler-with-cpp -Wa,--register-prefix-optional,--bitwise-or $(AFLAGS) -c $*.rs -o $@
-	$(CP) $*.d out/$*.d
+	$(CP) $*.d $(OUT)/$*.d
 	$(RM) $*.d
 
 %.rs: %.res
-	$(RESCOMP) $*.res $*.rs -dep out/$*.o
+	$(RESCOMP) $*.res $*.rs -dep $(OUT)/$*.o
 
 %.s: %.asm
 	$(MACCER) -o $@ $<
diff --git a/readme.md b/readme.md
index 66c0dd501..238715995 100644
--- a/readme.md
+++ b/readme.md
@@ -113,13 +113,15 @@ https://github.com/SONIC3D/gendev-macos
 
 *A modern way to install it on any environement is to use Docker.*
 
-To build the `sgdk` base image:
+To download the `sgdk` base image:
 
-    docker build -t sgdk .
+     docker pull ghcr.io/Stephane-D/sgdk
+     docker tag ghcr.io/Stephane-D/sgdk sgdk
 
-To build the `sgdk` base image on mac with m1 chip:
+Or build it:
 
-    docker build -t sgdk --file Dockerfile-m1 .
+     docker build -t ghcr.io/stephane-d/sgdk-m68k-gcc:latest -f deps/gcc.Dockerfile deps/
+     docker build -t sgdk .
 
 And then to compile the local env, such as `samples` for example:
 
diff --git a/tools/apj/src/sgdk/aplib/Launcher.java b/tools/apj/src/sgdk/aplib/Launcher.java
index aae60f9a1..dddf70678 100644
--- a/tools/apj/src/sgdk/aplib/Launcher.java
+++ b/tools/apj/src/sgdk/aplib/Launcher.java
@@ -1,4 +1,4 @@
-package sgdk.aplib;
+package sgdk.aplib;
 
 import java.io.File;
 import java.io.IOException;