lib/common.mk: init

We can simplify our Makefiles a bit by moving some things into a
library file.  So far, I've done this for non-component-specific
macros, and inference rules.

Some tar2ext4 rules used a temporary file for the tar2ext4 invocation,
and then moved the file into place when it was done, to prevent a
half-built image sticking around if tar2ext4 died.  According to
POSIX, make should clean up any targets that didn't finish building if
it's interrupted, so we should only end up with a half-built image if
tar2ext4 crashes, e.g. due to running out of disk space.  I think we
should just ignore that possibility, since otherwise we'd have to
write annoying make rules using temporary file names for every target,
and if it does happen recovery is just a make clean away.

With this, I've also made a small reorganisation.  I got rid of the
"nix" directory and created a "lib" directory, where I put
eval-config.nix and the new common.mk file, since both are library
code.  checks.nix isn't really a library though, so I moved it into
the "release" directory, since the only reference to it is in
release.nix.

Signed-off-by: Alyssa Ross <hi@alyssa.is>

32 files changed, 58 insertions, 87 deletions

diff --git a/Documentation/default.nix b/Documentation/default.nix
index 90f8e88..b0fe341 100644
--- a/Documentation/default.nix
+++ b/Documentation/default.nix
@@ -2,7 +2,7 @@
 # SPDX-FileCopyrightText: 2022 Unikie
 # SPDX-License-Identifier: MIT
 
-import ../nix/eval-config.nix ({ config, src, ... }: config.pkgs.callPackage (
+import ../lib/eval-config.nix ({ config, src, ... }: config.pkgs.callPackage (
 
 { lib, stdenvNoCC, jekyll, drawio-headless }:
 
diff --git a/Documentation/jekyll.nix b/Documentation/jekyll.nix
index fe16186..4b32ebe 100644
--- a/Documentation/jekyll.nix
+++ b/Documentation/jekyll.nix
@@ -1,7 +1,7 @@
 # SPDX-FileCopyrightText: 2022 Alyssa Ross <hi@alyssa.is>
 # SPDX-License-Identifier: MIT
 
-import ../nix/eval-config.nix ({ config, ... }: config.pkgs.callPackage (
+import ../lib/eval-config.nix ({ config, ... }: config.pkgs.callPackage (
 
 { bundlerApp }:
 
diff --git a/host/initramfs/Makefile b/host/initramfs/Makefile
index b0e236f..e341d1a 100644
--- a/host/initramfs/Makefile
+++ b/host/initramfs/Makefile
@@ -1,16 +1,7 @@
 # SPDX-License-Identifier: EUPL-1.2+
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-# qemu-kvm is non-standard, but is present in at least Fedora and
-# Nixpkgs.  If you don't have qemu-kvm, you'll need to set e.g.
-# QEMU_KVM = qemu-system-x86_64 -enable-kvm.
-QEMU_KVM = qemu-kvm
-
-CPIO = cpio
-CPIOFLAGS = --reproducible -R +0:+0 -H newc
-TAR = tar
-TAR2EXT4 = tar2ext4
-VERITYSETUP = veritysetup
+include ../../lib/common.mk
 
 RUN_IMAGE = build/live.img
 
@@ -65,10 +56,6 @@ build/live.img: ../../scripts/format-uuid.sh ../../scripts/make-gpt.sh build/roo
 build/loop.tar: build/live.img
 	$(TAR) -cf $@ build/live.img
 
-.SUFFIXES: .ext4 .tar
-.tar.ext4:
-	$(TAR2EXT4) -i $< -o $@
-
 build/loop.img: ../../scripts/make-gpt.sh build/loop.ext4
 	../../scripts/make-gpt.sh $@.tmp \
 	    build/loop.ext4:56a3bbc3-aefa-43d9-a64d-7b3fd59bbc4e
diff --git a/host/initramfs/default.nix b/host/initramfs/default.nix
index 828ba5d..154ae41 100644
--- a/host/initramfs/default.nix
+++ b/host/initramfs/default.nix
@@ -1,7 +1,7 @@
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 # SPDX-License-Identifier: MIT
 
-import ../../nix/eval-config.nix (
+import ../../lib/eval-config.nix (
 { config, src
 , rootfs ? import ../rootfs { inherit config; }
 , ...
diff --git a/host/initramfs/shell.nix b/host/initramfs/shell.nix
index 5475737..73e215d 100644
--- a/host/initramfs/shell.nix
+++ b/host/initramfs/shell.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-import ../../nix/eval-config.nix ({ config, ... } @ args:
+import ../../lib/eval-config.nix ({ config, ... } @ args:
 
 let
   inherit (config) pkgs;
diff --git a/host/rootfs/Makefile b/host/rootfs/Makefile
index 4c187b0..f4b17a0 100644
--- a/host/rootfs/Makefile
+++ b/host/rootfs/Makefile
@@ -1,18 +1,7 @@
 # SPDX-License-Identifier: EUPL-1.2+
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-# qemu-kvm is non-standard, but is present in at least Fedora and
-# Nixpkgs.  If you don't have qemu-kvm, you'll need to set e.g.
-# QEMU_KVM = qemu-system-x86_64 -enable-kvm.
-QEMU_KVM = qemu-kvm
-
-VERITYSETUP = veritysetup
-
-# tar2ext4 will leave half a filesystem behind if it's interrupted
-# half way through.
-build/rootfs.ext4: build/rootfs.tar
-	tar2ext4 -i build/rootfs.tar -o $@.tmp
-	mv $@.tmp $@
+include ../../lib/common.mk
 
 FILES = \
 	etc/fonts/fonts.conf \
@@ -47,6 +36,8 @@ LINKS = bin sbin
 
 BUILD_FILES = build/etc/mdev/modalias.sh build/etc/s6-rc
 
+build/rootfs.ext4:
+
 build/empty:
 	mkdir -p $@
 
diff --git a/host/rootfs/default.nix b/host/rootfs/default.nix
index acc0719..95bb3a8 100644
--- a/host/rootfs/default.nix
+++ b/host/rootfs/default.nix
@@ -2,7 +2,7 @@
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 # SPDX-FileCopyrightText: 2022 Unikie
 
-import ../../nix/eval-config.nix (
+import ../../lib/eval-config.nix (
 { config, src, ... }: let inherit (config) pkgs; in
 pkgs.pkgsStatic.callPackage (
 
diff --git a/host/rootfs/shell.nix b/host/rootfs/shell.nix
index 94e84be..fea9b16 100644
--- a/host/rootfs/shell.nix
+++ b/host/rootfs/shell.nix
@@ -2,7 +2,7 @@
 # SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
 # SPDX-FileCopyrightText: 2022 Unikie
 
-import ../../nix/eval-config.nix ({ config, ... } @ args:
+import ../../lib/eval-config.nix ({ config, ... } @ args:
 
 let
   rootfs = import ./. { inherit config; };
diff --git a/host/start-vm/default.nix b/host/start-vm/default.nix
index 767a967..f0709cd 100644
--- a/host/start-vm/default.nix
+++ b/host/start-vm/default.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2022 Alyssa Ross <hi@alyssa.is>
 
-import ../../nix/eval-config.nix ({ config, src, ... }: config.pkgs.callPackage (
+import ../../lib/eval-config.nix ({ config, src, ... }: config.pkgs.callPackage (
 { lib, stdenv, meson, ninja, rustc }:
 
 let
diff --git a/host/start-vm/shell.nix b/host/start-vm/shell.nix
index cbc1fee..f470233 100644
--- a/host/start-vm/shell.nix
+++ b/host/start-vm/shell.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
 
-import ../../nix/eval-config.nix ({ config, ... }:
+import ../../lib/eval-config.nix ({ config, ... }:
 
 with config.pkgs;
 
diff --git a/img/app/Makefile b/img/app/Makefile
index 7a59693..9649403 100644
--- a/img/app/Makefile
+++ b/img/app/Makefile
@@ -1,11 +1,7 @@
 # SPDX-License-Identifier: EUPL-1.2+
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-# qemu-kvm is non-standard, but is present in at least Fedora and
-# Nixpkgs.  If you don't have qemu-kvm, you'll need to set e.g.
-# QEMU_KVM = qemu-system-x86_64 -enable-kvm.
-QEMU_KVM = qemu-kvm
-CLOUD_HYPERVISOR = cloud-hypervisor
+include ../../lib/common.mk
 
 prefix = /usr/local
 imgdir = $(prefix)/img
@@ -34,13 +30,6 @@ build/host/appvm/blk/root.img: ../../scripts/make-gpt.sh ../../scripts/sfdisk-fi
 	    build/rootfs.ext4:4f68bce3-e8cd-4db1-96e7-fbcaf984b709:5460386f-2203-4911-8694-91400125c604:root
 	mv $@.tmp $@
 
-# tar2ext4 will leave half a filesystem behind if it's interrupted
-# half way through.
-build/rootfs.ext4: build/rootfs.tar
-	mkdir -p $$(dirname $@)
-	tar2ext4 -i build/rootfs.tar -o $@.tmp
-	mv $@.tmp $@
-
 VM_FILES = \
 	etc/fstab \
 	etc/init \
diff --git a/img/app/default.nix b/img/app/default.nix
index 7aa22ad..dbffff0 100644
--- a/img/app/default.nix
+++ b/img/app/default.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-import ../../nix/eval-config.nix (
+import ../../lib/eval-config.nix (
 { config, src, terminfo ? config.pkgs.foot.terminfo, ... }:
 config.pkgs.pkgsStatic.callPackage (
 
diff --git a/img/app/shell.nix b/img/app/shell.nix
index 7a323aa..9fe6031 100644
--- a/img/app/shell.nix
+++ b/img/app/shell.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-import ../../nix/eval-config.nix (
+import ../../lib/eval-config.nix (
 { config, run ? ../../vm/app/catgirl.nix, ... }:
 
 with config.pkgs;
diff --git a/lib/common.mk b/lib/common.mk
new file mode 100644
index 0000000..efa04a0
--- /dev/null
+++ b/lib/common.mk
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2021, 2023 Alyssa Ross <hi@alyssa.is>
+
+.POSIX:
+
+# qemu-kvm is non-standard, but is present in at least Fedora and
+# Nixpkgs.  If you don't have qemu-kvm, you'll need to set e.g.
+# QEMU_KVM = qemu-system-x86_64 -enable-kvm.
+QEMU_KVM = qemu-kvm
+
+CLOUD_HYPERVISOR = cloud-hypervisor
+CPIO = cpio
+CPIOFLAGS = --reproducible -R +0:+0 -H newc
+MCOPY = mcopy
+MKFS_FAT = mkfs.fat
+MMD = mmd
+OBJCOPY = objcopy
+TAR = tar
+TAR2EXT4 = tar2ext4
+TRUNCATE = truncate
+VERITYSETUP = veritysetup
+
+.SUFFIXES: .ext4 .tar
+.tar.ext4:
+	$(TAR2EXT4) -i $< -o $@
diff --git a/nix/eval-config.nix b/lib/eval-config.nix
index 78cdeae..78cdeae 100644
--- a/nix/eval-config.nix
+++ b/lib/eval-config.nix
diff --git a/release.nix b/release.nix
index 707c86c..7f758ae 100644
--- a/release.nix
+++ b/release.nix
@@ -3,10 +3,10 @@
 
 # This file is built to populate the binary cache.
 
-import nix/eval-config.nix ({ config, ... }: {
+import lib/eval-config.nix ({ config, ... }: {
   doc = import ./Documentation { inherit config; };
 
-  checks = import nix/checks.nix { inherit config; };
+  checks = import release/checks.nix { inherit config; };
 
   combined = import release/combined/run-vm.nix { inherit config; };
 })
diff --git a/nix/checks.nix b/release/checks.nix
index d5a40c0..ee79c8d 100644
--- a/nix/checks.nix
+++ b/release/checks.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2022 Unikie
 
-import ../nix/eval-config.nix ({ config, src, ... }: {
+import ../lib/eval-config.nix ({ config, src, ... }: {
   recurseForDerivations = true;
 
   doc-links = config.pkgs.callPackage (
diff --git a/release/combined/default.nix b/release/combined/default.nix
index 7f7b3a2..6740497 100644
--- a/release/combined/default.nix
+++ b/release/combined/default.nix
@@ -3,7 +3,7 @@
 # SPDX-FileCopyrightText: 2021 Yureka <yuka@yuka.dev>
 # SPDX-FileCopyrightText: 2022 Unikie
 
-import ../../nix/eval-config.nix ({ config, ... } @ args: with config.pkgs;
+import ../../lib/eval-config.nix ({ config, ... } @ args: with config.pkgs;
 
 let
   inherit (builtins) storeDir;
diff --git a/release/combined/eosimages.nix b/release/combined/eosimages.nix
index b2dba13..5850b15 100644
--- a/release/combined/eosimages.nix
+++ b/release/combined/eosimages.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-import ../../nix/eval-config.nix ({ config, ... }: with config.pkgs;
+import ../../lib/eval-config.nix ({ config, ... }: with config.pkgs;
 
 runCommand "eosimages.img" {
   nativeBuildInputs = [ e2fsprogs tar2ext4 ];
diff --git a/release/combined/run-vm.nix b/release/combined/run-vm.nix
index 10bd8bf..819f549 100644
--- a/release/combined/run-vm.nix
+++ b/release/combined/run-vm.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
 
-import ../../nix/eval-config.nix ({ config, ... }: with config.pkgs;
+import ../../lib/eval-config.nix ({ config, ... }: with config.pkgs;
 
 let
   image = import ./. { inherit config; };
diff --git a/release/installer/default.nix b/release/installer/default.nix
index 16a7d35..44f3be2 100644
--- a/release/installer/default.nix
+++ b/release/installer/default.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-import ../../nix/eval-config.nix ({ config, extraConfig ? {}, ... }:
+import ../../lib/eval-config.nix ({ config, extraConfig ? {}, ... }:
 with config.pkgs;
 
 let
diff --git a/release/installer/run-vm.nix b/release/installer/run-vm.nix
index c42155b..024bd5d 100644
--- a/release/installer/run-vm.nix
+++ b/release/installer/run-vm.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-import ../../nix/eval-config.nix ({ config, ... }:
+import ../../lib/eval-config.nix ({ config, ... }:
 
 let
   inherit (builtins) storeDir;
diff --git a/release/live/Makefile b/release/live/Makefile
index f887f0a..4eeeaa6 100644
--- a/release/live/Makefile
+++ b/release/live/Makefile
@@ -1,17 +1,7 @@
 # SPDX-License-Identifier: EUPL-1.2+
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-# qemu-kvm is non-standard, but is present in at least Fedora and
-# Nixpkgs.  If you don't have qemu-kvm, you'll need to set e.g.
-# QEMU_KVM = qemu-system-x86_64 -enable-kvm.
-QEMU_KVM = qemu-kvm
-
-MCOPY = mcopy
-MKFS_FAT = mkfs.fat
-MMD = mmd
-OBJCOPY = objcopy
-TRUNCATE = truncate
-VERITYSETUP = veritysetup
+include ../../lib/common.mk
 
 build/live.img: ../../scripts/format-uuid.sh ../../scripts/make-gpt.sh build/boot.fat build/rootfs.verity.superblock build/rootfs.verity.roothash $(ROOT_FS) $(EXT_FS)
 	../../scripts/make-gpt.sh $@.tmp \
diff --git a/release/live/default.nix b/release/live/default.nix
index c36c34b..cdbd348 100644
--- a/release/live/default.nix
+++ b/release/live/default.nix
@@ -2,7 +2,7 @@
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 # SPDX-FileCopyrightText: 2022 Unikie
 
-import ../../nix/eval-config.nix ({ config, src, ... }:
+import ../../lib/eval-config.nix ({ config, src, ... }:
 config.pkgs.callPackage (
 
 { stdenvNoCC, cryptsetup, dosfstools, jq, mtools, util-linux, stdenv
diff --git a/release/live/shell.nix b/release/live/shell.nix
index 7cec144..577b714 100644
--- a/release/live/shell.nix
+++ b/release/live/shell.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-import ../../nix/eval-config.nix ({ config, ... }:
+import ../../lib/eval-config.nix ({ config, ... }:
 
 with config.pkgs;
 
diff --git a/shell.nix b/shell.nix
index c249aa6..bcb3de9 100644
--- a/shell.nix
+++ b/shell.nix
@@ -2,7 +2,7 @@
 # SPDX-FileCopyrightText: 2022 Unikie
 # SPDX-License-Identifier: MIT
 
-import nix/eval-config.nix ({ config, ... }: with config.pkgs;
+import lib/eval-config.nix ({ config, ... }: with config.pkgs;
 
 mkShell {
   nativeBuildInputs = [ b4 reuse rustfmt ];
diff --git a/vm/app/catgirl.nix b/vm/app/catgirl.nix
index f74acc9..7cd76a9 100644
--- a/vm/app/catgirl.nix
+++ b/vm/app/catgirl.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-import ../../nix/eval-config.nix ({ config, ... }:
+import ../../lib/eval-config.nix ({ config, ... }:
 
 import ../make-vm.nix { inherit config; } {
   providers.net = [ "netvm" ];
diff --git a/vm/app/lynx.nix b/vm/app/lynx.nix
index d0b36a0..21cb56e 100644
--- a/vm/app/lynx.nix
+++ b/vm/app/lynx.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-import ../../nix/eval-config.nix ({ config, ... }:
+import ../../lib/eval-config.nix ({ config, ... }:
 
 import ../make-vm.nix { inherit config; } {
   providers.net = [ "netvm" ];
diff --git a/vm/make-vm.nix b/vm/make-vm.nix
index da3bdf7..d33cedd 100644
--- a/vm/make-vm.nix
+++ b/vm/make-vm.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2022 Alyssa Ross <hi@alyssa.is>
 
-import ../nix/eval-config.nix ({ config, ... }:
+import ../lib/eval-config.nix ({ config, ... }:
 
 import ../vm-lib/make-vm.nix {
   inherit (config) pkgs;
diff --git a/vm/sys/net/Makefile b/vm/sys/net/Makefile
index 076e991..cb294a4 100644
--- a/vm/sys/net/Makefile
+++ b/vm/sys/net/Makefile
@@ -1,11 +1,7 @@
 # SPDX-License-Identifier: EUPL-1.2+
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-# qemu-kvm is non-standard, but is present in at least Fedora and
-# Nixpkgs.  If you don't have qemu-kvm, you'll need to set e.g.
-# QEMU_KVM = qemu-system-x86_64 -enable-kvm.
-QEMU_KVM = qemu-kvm
-CLOUD_HYPERVISOR = cloud-hypervisor
+include ../../../lib/common.mk
 
 VMM = qemu
 
@@ -36,13 +32,6 @@ build/host/data/netvm/blk/root.img: ../../../scripts/make-gpt.sh ../../../script
 	    build/rootfs.ext4:4f68bce3-e8cd-4db1-96e7-fbcaf984b709:ea21da27-0391-48da-9235-9d2ab2ca7844:root
 	mv $@.tmp $@
 
-# tar2ext4 will leave half a filesystem behind if it's interrupted
-# half way through.
-build/rootfs.ext4: build/rootfs.tar
-	mkdir -p $$(dirname $@)
-	tar2ext4 -i build/rootfs.tar -o $@.tmp
-	mv $@.tmp $@
-
 VM_FILES = \
 	etc/dbus-1/system.conf \
 	etc/fstab \
diff --git a/vm/sys/net/default.nix b/vm/sys/net/default.nix
index a30f5f5..a7f6cc0 100644
--- a/vm/sys/net/default.nix
+++ b/vm/sys/net/default.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-import ../../../nix/eval-config.nix (
+import ../../../lib/eval-config.nix (
 { config, src, terminfo ? config.pkgs.foot.terminfo, ... }:
 config.pkgs.pkgsStatic.callPackage (
 
diff --git a/vm/sys/net/shell.nix b/vm/sys/net/shell.nix
index f298431..c0771e8 100644
--- a/vm/sys/net/shell.nix
+++ b/vm/sys/net/shell.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
 
-import ../../../nix/eval-config.nix ({ config, ... }: with config.pkgs;
+import ../../../lib/eval-config.nix ({ config, ... }: with config.pkgs;
 
 (import ./. { inherit config; }).overrideAttrs (
 { passthru ? {}, nativeBuildInputs ? [], ... }: