[PATCH v2 3/3] Common make rules for building erofs images

Demi Marie Obenour
2025-09-10T05:37:37Z

Instead of duplicating the logic in three different places, write common
code for all three makefiles to use instead. This will make future
changes much easier.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
---
host/rootfs/Makefile | 45 +++------------------------------------------
host/rootfs/default.nix | 1 +
img/app/Makefile | 41 ++---------------------------------------
img/app/default.nix | 1 +
lib/erofs.mk | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
vm/sys/net/Makefile | 39 ++++-----------------------------------
vm/sys/net/default.nix | 1 +
7 files changed, 61 insertions(+), 116 deletions(-)

diff --git a/host/rootfs/Makefile b/host/rootfs/Makefile
index 795d0018ea2858c4d21a9ec42370597fd102473a..e100c9fa240d76a0210b553f5aaa34de93b05e78 100644
--- a/host/rootfs/Makefile
+++ b/host/rootfs/Makefile
@@ -3,10 +3,8 @@

.POSIX:

-include ../../lib/common.mk
-include file-list.mk
-
-dest = build/rootfs.erofs
+basedir = ../..
+include $(basedir)/lib/erofs.mk

DIRS = \
dev \
@@ -44,44 +42,7 @@ DIRS = \

FIFOS = etc/s6-linux-init/run-image/service/s6-svscan-log/fifo

-BUILD_FILES = build/etc/s6-rc
-
-$(dest): ../../scripts/make-erofs.sh $(PACKAGES_FILE) $(FILES) $(BUILD_FILES) build/empty build/fifo file-list.mk
- ( \
- cat $(PACKAGES_FILE) ;\
- for file in $(FILES) $(LINKS); do printf '%s\n%s\n' $$file "$${file#image/}"; done ;\
- for file in $(BUILD_FILES); do printf '%s\n%s\n' $$file $${file#build/}; done ;\
- printf 'build/empty\n%s\n' $(DIRS) ;\
- printf 'build/fifo\n%s\n' $(FIFOS) ;\
- ) | ../../scripts/make-erofs.sh $@
-
-build/fifo:
- mkdir -p build
- mkfifo -m 0600 $@
-
-build/empty:
- mkdir -p $@
-
-# s6-rc-compile's input is a directory, but that doesn't play nice
-# with Make, because it won't know to update if some file in the
-# directory is changed, or a file is created or removed in a
-# subdirectory. Using the whole source directory could also end up
-# including files that aren't intended to be part of the input, like
-# temporary editor files or .license files. So for all these reasons,
-# only explicitly listed files are made available to s6-rc-compile.
-build/etc/s6-rc: $(S6_RC_FILES) file-list.mk
- mkdir -p $$(dirname $@)
- rm -rf $@
-
- dir=$$(mktemp -d) && \
- tar -c $(S6_RC_FILES) | tar -C $$dir -x --strip-components 3 && \
- s6-rc-compile $@ $$dir; \
- exit=$$?; rm -r $$dir; exit $$exit
-
-clean:
- -chmod -Rf +w build
- rm -rf build
-.PHONY: clean
+all: $(dest)

# veritysetup format produces two files, but Make only (portably)
# supports one output per rule, so we combine the two outputs then
diff --git a/host/rootfs/default.nix b/host/rootfs/default.nix
index 998220d7b6ed322f64ee52c704e71ec9b4643f59..561bf660829dcd5f5e2ee841662727b262d43ed3 100644
--- a/host/rootfs/default.nix
+++ b/host/rootfs/default.nix
@@ -178,6 +178,7 @@ stdenvNoCC.mkDerivation {
fileset = fileset.intersection src (fileset.unions [
./.
../../lib/common.mk
+ ../../lib/erofs.mk
../../scripts/make-erofs.sh
]);
};
diff --git a/img/app/Makefile b/img/app/Makefile
index 04fbf99c7d2e30527aa54e5e549043d03ce6362b..409c0156bf0d336c17dec6e2324e6fbd6bd4c788 100644
--- a/img/app/Makefile
+++ b/img/app/Makefile
@@ -4,8 +4,8 @@

.POSIX:

-include ../../lib/common.mk
-include file-list.mk
+basedir = ../..
+include $(basedir)/lib/erofs.mk

prefix = build/host
libdir = $(prefix)/lib
@@ -18,7 +18,6 @@ HOST_BUILD_FILES = \
$(imgdir)/appvm/vmlinux

all: $(HOST_BUILD_FILES)
-.PHONY: all

$(imgdir)/appvm/vmlinux: $(KERNEL)
mkdir -p $$(dirname $@)
@@ -36,33 +35,6 @@ DIRS = dev run proc sys tmp \
etc/s6-linux-init/run-image/wait
FIFOS = etc/s6-linux-init/run-image/service/s6-linux-init-shutdownd/fifo

-BUILD_FILES = build/etc/s6-rc
-
-build/fifo:
- mkdir -p build
- mkfifo -m 0600 $@
-
-build/empty:
- mkdir -p $@
-
-build/rootfs.erofs: ../../scripts/make-erofs.sh $(PACKAGES_FILE) $(addprefix image/,$(FILES)) $(BUILD_FILES) build/empty build/fifo file-list.mk
- ( \
- cat $(PACKAGES_FILE) ;\
- for file in $(FILES) $(LINKS); do printf 'image/%s\n%s\n' $$file $$file; done ;\
- for file in $(BUILD_FILES); do printf '%s\n%s\n' $$file $${file#build/}; done ;\
- printf 'build/empty\n%s\n' $(DIRS) ;\
- printf 'build/fifo\n%s\n' $(FIFOS) ;\
- ) | ../../scripts/make-erofs.sh $@
-
-
-build/etc/s6-rc: $(S6_RC_FILES) file-list.mk
- mkdir -p $$(dirname $@)
- rm -rf $@
-
- dir=$$(mktemp -d) && \
- tar -C image -c $(S6_RC_FILES) | tar -C $$dir -x --strip-components 3 && \
- s6-rc-compile $@ $$dir; \
- exit=$$?; rm -r $$dir; exit $$exit

debug:
$(GDB) -q \
@@ -139,14 +111,5 @@ run-crosvm: $(imgdir)/appvm/blk/root.img start-vhost-user-gpu start-virtiofsd
$(KERNEL)
.PHONY: run-crosvm

-update-file-list:
- ../../scripts/genfiles.awk image > file-list.mk
-
-.PHONY: update-file-list
-
run: run-$(VMM)
.PHONY: run
-
-clean:
- rm -rf build
-.PHONY: clean
diff --git a/img/app/default.nix b/img/app/default.nix
index 71a939c1c053ebd37fc02fa4eed49b883d50ef49..8c2a114e6b4db52afe9c92f9adb3d5ec52ea2260 100644
--- a/img/app/default.nix
+++ b/img/app/default.nix
@@ -105,6 +105,7 @@ stdenvNoCC.mkDerivation {
fileset = lib.fileset.intersection src (lib.fileset.unions [
./.
../../lib/common.mk
+ ../../lib/erofs.mk
../../scripts/make-erofs.sh
../../scripts/make-gpt.sh
../../scripts/sfdisk-field.awk
diff --git a/lib/erofs.mk b/lib/erofs.mk
new file mode 100644
index 0000000000000000000000000000000000000000..1166e2153eb8fde48558affb2a59198a0f0ea917
--- /dev/null
+++ b/lib/erofs.mk
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2021-2024 Alyssa Ross <hi@alyssa.is>
+# SPDX-FileCopyrightText: 2022 Unikie
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+include $(basedir)/lib/common.mk
+include file-list.mk
+BUILD_FILES += build/etc/s6-rc
+dest = build/rootfs.erofs
+
+all:
+.PHONY: all
+$(dest): $(basedir)/scripts/make-erofs.sh $(PACKAGES_FILE) $(FILES) $(BUILD_FILES) build/empty build/fifo file-list.mk
+ set -euo pipefail; ( \
+ cat $(PACKAGES_FILE);\
+ for file in $(FILES) $(LINKS); do printf '%s\n%s\n' "$$file" "$${file#image/}"; done;\
+ for file in $(BUILD_FILES); do printf '%s\n%s\n' "$$file" "$${file#build/}"; done;\
+ for dir in $(DIRS); do printf 'build/empty\n%s\n' "$$dir"; done;\
+ for fifo in $(FIFOS); do printf 'build/fifo\n%s\n' "$$fifo"; done;\
+ ) | $(basedir)/scripts/make-erofs.sh $@
+
+clean:
+ -chmod -Rf +w build
+ rm -rf build
+.PHONY: clean
+ false
+
+build/fifo:
+ mkdir -p build
+ mkfifo -m 0600 $@
+
+build/empty:
+ mkdir -p $@
+
+# s6-rc-compile's input is a directory, but that doesn't play nice
+# with Make, because it won't know to update if some file in the
+# directory is changed, or a file is created or removed in a
+# subdirectory. Using the whole source directory could also end up
+# including files that aren't intended to be part of the input, like
+# temporary editor files or .license files. So for all these reasons,
+# only explicitly listed files are made available to s6-rc-compile.
+build/etc/s6-rc: $(S6_RC_FILES) file-list.mk
+ mkdir -p build/etc
+ rm -rf $@
+ set -euo pipefail; \
+ dir=$$(mktemp -d); \
+ { tar -c $(S6_RC_FILES) | tar -C "$$dir" -x --strip-components 3;}; \
+ s6-rc-compile $@ $$dir; \
+ exit=$$?; rm -r $$dir; exit $$exit
diff --git a/vm/sys/net/Makefile b/vm/sys/net/Makefile
index 11f9215b58a89569ead0c5cc7a4a24b0cc4eec22..217f95bfeabd80bc6fea1e3264296891ee495ee5 100644
--- a/vm/sys/net/Makefile
+++ b/vm/sys/net/Makefile
@@ -3,21 +3,22 @@

.POSIX:

-include ../../../lib/common.mk
-include file-list.mk
+basedir = ../../..
+include $(basedir)/lib/erofs.mk

prefix = build/host
libdir = $(prefix)/lib
vmdir = $(libdir)/spectrum/vm

VMM = cloud-hypervisor
+DIRS =
+FIFOS =

HOST_BUILD_FILES = \
$(vmdir)/netvm/blk/root.img \
$(vmdir)/netvm/vmlinux

all: $(HOST_BUILD_FILES)
-.PHONY: all

$(vmdir)/netvm/vmlinux: $(KERNEL)
mkdir -p $$(dirname $@)
@@ -29,29 +30,6 @@ $(vmdir)/netvm/blk/root.img: ../../../scripts/make-gpt.sh ../../../scripts/sfdis
build/rootfs.erofs:root:ea21da27-0391-48da-9235-9d2ab2ca7844:root
mv $@.tmp $@

-BUILD_FILES = build/etc/s6-rc
-
-build/empty:
- mkdir -p $@
-
-build/rootfs.erofs: ../../../scripts/make-erofs.sh $(PACKAGES_FILE) $(FILES) $(BUILD_FILES) build/empty file-list.mk
- ( \
- cat $(PACKAGES_FILE) ;\
- for file in $(FILES) $(LINKS); do printf '%s\n%s\n' $$file "$${file#image/}"; done ;\
- for file in $(BUILD_FILES); do printf '%s\n%s\n' $$file $${file#build/}; done ;\
- printf 'build/empty\n%s\n' $(DIRS) ;\
- ) | ../../../scripts/make-erofs.sh $@
-
-
-build/etc/s6-rc: $(S6_RC_FILES) file-list.mk
- mkdir -p $$(dirname $@)
- rm -rf $@
-
- dir=$$(mktemp -d) && \
- tar -c $(S6_RC_FILES) | tar -C $$dir -x --strip-components 3 && \
- s6-rc-compile $@ $$dir; \
- exit=$$?; rm -r $$dir; exit $$exit
-
debug:
$(GDB) -q \
-ex 'set substitute-path .. $(LINUX_SRC)' \
@@ -103,14 +81,5 @@ run-crosvm: $(vmdir)/netvm/blk/root.img
$(KERNEL)
.PHONY: run-crosvm

-update-file-list:
- ../../scripts/genfiles.awk image > file-list.mk
-
-.PHONY: update-file-list
-
run: run-$(VMM)
.PHONY: run
-
-clean:
- rm -rf build
-.PHONY: clean
diff --git a/vm/sys/net/default.nix b/vm/sys/net/default.nix
index 7b2b8b1fbb9b9027781812307bed0551b80f5a78..c453f02cb204e97d0627b18c66c29a9767159d40 100644
--- a/vm/sys/net/default.nix
+++ b/vm/sys/net/default.nix
@@ -104,6 +104,7 @@ stdenvNoCC.mkDerivation {
fileset = lib.fileset.intersection src (lib.fileset.unions [
./.
../../../lib/common.mk
+ ../../../lib/erofs.mk
../../../scripts/make-erofs.sh
../../../scripts/make-gpt.sh
../../../scripts/sfdisk-field.awk

--
2.51.0