diff --git a/_dev/Makefile b/_dev/Makefile
index 05309b7..82d5a8f 100644
--- a/_dev/Makefile
+++ b/_dev/Makefile
@@ -1,27 +1,58 @@
+# Constants
+MK_FILE_PATH = $(lastword $(MAKEFILE_LIST))
+PRJ_DIR      = $(abspath $(dir $(MK_FILE_PATH))/..)
+DEV_DIR      = $(PRJ_DIR)/_dev
+# Results will be produced in this directory (can be provided by a caller)
+BUILD_DIR   ?= $(PRJ_DIR)/_dev/GOROOT
+
+# Compiler
 GO ?= go
-GOENV := $(shell $(GO) env GOHOSTOS)_$(shell $(GO) env GOHOSTARCH)
-GOROOTINFO := $(shell $(GO) version | cut -d' ' -f 3)_$(GOENV)
-
-.PHONY: GOROOT
-GOROOT: GOROOT/$(GOENV)/.ok_$(GOROOTINFO)
-	@rm -f GOROOT/$(GOENV)/pkg/*/crypto/tls.a
-
-GOROOT/$(GOENV)/.ok_$(GOROOTINFO):
-	$(eval GOROOT := $(CURDIR)/GOROOT/$(GOENV))
-	rm -rf "$(GOROOT)"
-	mkdir -p "$(GOROOT)/pkg"
-	cp -r "$(shell $(GO) env GOROOT)/src" "$(GOROOT)/src"
-	cp -r "$(shell $(GO) env GOROOT)/pkg/include" "$(GOROOT)/pkg/include"
-	cp -r "$(shell $(GO) env GOROOT)/pkg/tool" "$(GOROOT)/pkg/tool"
-	rm -r "$(GOROOT)/src/crypto/tls"
-	ln -s ../../../../.. "$(GOROOT)/src/crypto/tls"
-	for p in $(wildcard $(CURDIR)/patches/*); do patch -d "$(GOROOT)" -p1 < "$$p"; done
-	GOROOT="$(GOROOT)" $(GO) install -v std
-ifeq ($(shell go env CGO_ENABLED),1)
-	GOROOT="$(GOROOT)" $(GO) install -race -v std
+
+# Build environment
+OS          ?= $(shell $(GO) env GOHOSTOS)
+ARCH        ?= $(shell $(GO) env GOHOSTARCH)
+OS_ARCH     := $(OS)_$(ARCH)
+VER_OS_ARCH := $(shell $(GO) version | cut -d' ' -f 3)_$(OS)_$(ARCH)
+GOROOT_ENV  := $(shell $(GO) env GOROOT)
+GOROOT_LOCAL = $(BUILD_DIR)/$(OS_ARCH)
+# Flag indicates wheter invoke "go install -race std". Supported only on amd64 with CGO enabled
+INSTALL_RACE:= $(words $(filter $(ARCH)_$(shell go env CGO_ENABLED), amd64_1))
+
+# TODO: I'm not sure why we would remove it at the end
+#       but I comment this code as tls.a is exactly what
+#       I try to build here
+#GOROOT: GOROOT/$(OS_ARCH)/.ok_$(VER_OS_ARCH)
+#	rm -f GOROOT/$(OS_ARCH)/pkg/*/crypto/tls.a
+
+$(BUILD_DIR)/$(OS_ARCH)/.ok_$(VER_OS_ARCH): clean
+
+# Create clean directory structure
+	mkdir -p "$(GOROOT_LOCAL)/pkg"
+
+# Copy src/tools from system GOROOT
+	cp -r $(GOROOT_ENV)/src $(GOROOT_LOCAL)/src
+	cp -r $(GOROOT_ENV)/pkg/include $(GOROOT_LOCAL)/pkg/include
+	cp -r $(GOROOT_ENV)/pkg/tool $(GOROOT_LOCAL)/pkg/tool
+
+# Swap TLS implementation
+	rm -r $(GOROOT_LOCAL)/src/crypto/tls/*
+	rsync -a $(PRJ_DIR)/ $(GOROOT_LOCAL)/src/crypto/tls/ --exclude=$(lastword $(subst /, ,$(DEV_DIR)))
+
+# Apply additional patches
+	for p in $(wildcard $(DEV_DIR)/patches/*); do patch -d "$(GOROOT_LOCAL)" -p1 < "$$p"; done
+
+# Create go package
+	GOARCH=$(ARCH) GOROOT="$(GOROOT_LOCAL)" $(GO) install -v std
+ifeq ($(INSTALL_RACE),1)
+	GOARCH=$(ARCH) GOROOT="$(GOROOT_LOCAL)" $(GO) install -race -v std
 endif
 	@touch "$@"
 
-.PHONY: clean
 clean:
-	rm -rf GOROOT go
+	rm -rf $(BUILD_DIR)/$(OS_ARCH)
+
+clean-all:
+	rm -rf $(BUILD_DIR)
+
+# PHONY targets
+.PHONY: $(BUILD_DIR) clean
diff --git a/_dev/bogo/Dockerfile b/_dev/bogo/Dockerfile
index 79b0789..cd6f69d 100644
--- a/_dev/bogo/Dockerfile
+++ b/_dev/bogo/Dockerfile
@@ -5,6 +5,7 @@ RUN apk add --update \
     make \
     bash \
     patch \
+    rsync \
   && rm -rf /var/cache/apk/*
 
 ENV CGO_ENABLED=0
diff --git a/_dev/go.sh b/_dev/go.sh
index 4fbc79e..c396d3f 100755
--- a/_dev/go.sh
+++ b/_dev/go.sh
@@ -4,7 +4,7 @@ set -e
 BASEDIR=$(cd "$(dirname "$0")" && pwd)
 GOENV="$(go env GOHOSTOS)_$(go env GOHOSTARCH)"
 
-make --quiet -C "$BASEDIR" GOROOT >&2
+BUILD_DIR=${BASEDIR}/GOROOT make -f $BASEDIR/Makefile >&2
 
 export GOROOT="$BASEDIR/GOROOT/$GOENV"
 exec go "$@"