Red Bear OS — microkernel OS in Rust, based on Redox

Derivative of Redox OS (https://www.redox-os.org) adding:
- AMD GPU driver (amdgpu) via LinuxKPI compat layer
- ext4 filesystem support (ext4d scheme daemon)
- ACPI fixes for AMD bare metal (x2APIC, DMAR, IVRS, MCFG)
- Custom branding (hostname, os-release, boot identity)

Build system is full upstream Redox with RBOS overlay in local/.
Patches for kernel, base, and relibc are symlinked from local/patches/
and protected from make clean/distclean. Custom recipes live in
local/recipes/ with symlinks into the recipes/ search path.

Build:  make all CONFIG_NAME=redbear-full
Sync:   ./local/scripts/sync-upstream.sh

mk/fstools.mk

@@ -0,0 +1,56 @@
+# Configuration file for the Red Bear OS installer, Cookbook and RedoxFS FUSE
+
+fstools: $(FSTOOLS_TAG) $(FSTOOLS)
+
+GOING_TO_PODMAN_AGAIN?=0
+
+# These tools run inside Podman if it is used, or on the host if Podman is not used
+$(FSTOOLS): | prefix $(CONTAINER_TAG) $(FSTOOLS_TAG)
+ifeq ($(PODMAN_BUILD),1)
+ifeq ($(FSTOOLS_IN_PODMAN),1)
+	$(PODMAN_RUN) make $@
+else
+	$(MAKE) $@ PODMAN_BUILD=0 SKIP_CHECK_TOOLS=1 GOING_TO_PODMAN_AGAIN=1
+endif
+else
+	rm -rf $@ $@.partial
+	mkdir -p $@.partial
+	ln -s ../../recipes $@.partial/recipes
+	$(MAKE) fstools_fetch PODMAN_BUILD=$(GOING_TO_PODMAN_AGAIN)
+
+	# Compile installer and redoxfs for host (may be outside of podman container)
+	cd $@.partial && \
+		export CARGO_TARGET_DIR=../$@-target && \
+		$(HOST_CARGO) install --root . --path recipes/core/installer/source --locked $(INSTALLER_FEATURES) && \
+		$(HOST_CARGO) install --root . --path recipes/core/redoxfs/source --locked $(REDOXFS_FEATURES)
+
+	mv $@.partial $@
+	touch $@
+endif
+
+fstools_fetch: $(FSTOOLS_TAG) FORCE
+ifeq ($(PODMAN_BUILD),1)
+	$(PODMAN_RUN) make $@
+else
+	$(REPO_BIN) fetch installer redoxfs
+endif
+
+CARGO_OFFLINE_FLAG=
+ifeq ($(REPO_OFFLINE),1)
+CARGO_OFFLINE_FLAG=--offline
+endif
+
+$(FSTOOLS_TAG): $(CONTAINER_TAG)
+ifeq ($(PODMAN_BUILD),1)
+	$(PODMAN_RUN) make $@
+else
+	$(HOST_CARGO) build --manifest-path Cargo.toml --release --locked $(CARGO_OFFLINE_FLAG)
+	mkdir -p $(@D)
+	touch $@
+endif
+
+fstools_clean: FORCE
+	rm -rf target
+	rm -rf $(FSTOOLS)
+	rm -rf $(FSTOOLS)-target
+	rm -f $(FSTOOLS_TAG)