commit 54a1ab3529c9294d12e1a3f4e0a7c5c8897afd0d
parent 25d9da967ce1ab5ef9fa483b0c9186559306f335
Author: Daniel Barlow <dan@telent.net>
Date: Tue, 4 Apr 2023 23:35:49 +0100
support jffs2, with initramfs
the jffs2 filesystem contains only /nix/store and a script which is
run in early init (initramfs) and is responsible for recreating
"traditional" directories (/bin /etc/**/* /var &c) based on the
configuration.
this is tested only in qemu so far and could use some cleanup
Diffstat:
5 files changed, 206 insertions(+), 3 deletions(-)
diff --git a/modules/initramfs.nix b/modules/initramfs.nix
@@ -0,0 +1,79 @@
+{
+ config
+, pkgs
+, lib
+, ...
+}:
+let
+# inherit (lib) mkOption types concatStringsSep;
+ inherit (pkgs) runCommand callPackage writeText;
+in
+{
+ config = {
+ kernel.config.BLK_DEV_INITRD = "y";
+
+ outputs = {
+ initramfs =
+ let
+ bb = pkgs.busybox.override {
+ enableStatic = true;
+ enableMinimal = true;
+ enableAppletSymlinks = false;
+ extraConfig = ''
+ CONFIG_ASH y
+ CONFIG_LS y
+ CONFIG_LN y
+ CONFIG_CAT y
+ CONFIG_MOUNT y
+ CONFIG_PRINTF y
+ CONFIG_FEATURE_MOUNT_FLAGS y
+ CONFIG_FEATURE_MOUNT_VERBOSE y
+ CONFIG_ECHO y
+ CONFIG_CHROOT y
+ CONFIG_CHMOD y
+ CONFIG_MKDIR y
+ CONFIG_MKNOD y
+ CONFIG_SH_IS_ASH y
+ CONFIG_BASH_IS_NONE y
+ '';
+ };
+ slashinit = pkgs.writeScript "init" ''
+ #!/bin/sh
+ exec >/dev/console
+ echo IT MOVES
+ mount -t proc none /proc
+ mount -t jffs2 mtd0 /target/persist
+ mount -o bind /target/persist/nix /target/nix
+ sh /target/persist/activate /target
+ cd /target
+ mount -o bind /target /
+ exec chroot . /bin/init "$@"
+ '';
+ refs = pkgs.writeReferencesToFile bb;
+ gen_init_cpio = pkgs.pkgsBuildBuild.gen_init_cpio;
+ in runCommand "initramfs" {} ''
+ cat << SPECIALS | ${gen_init_cpio}/bin/gen_init_cpio /dev/stdin > $out
+ dir /proc 0755 0 0
+ dir /dev 0755 0 0
+ nod /dev/mtdblock0 0600 0 0 b 31 0
+ dir /target 0755 0 0
+ dir /target/persist 0755 0 0
+ dir /target/nix 0755 0 0
+ nod /dev/console 0600 0 0 c 5 1
+ dir /bin 0755 0 0
+ file /bin/busybox ${bb}/bin/busybox 0755 0 0
+ slink /bin/sh /bin/busybox 0755 0 0
+ slink /bin/echo /bin/busybox 0755 0 0
+ slink /bin/mount /bin/busybox 0755 0 0
+ slink /bin/chroot /bin/busybox 0755 0 0
+ slink /bin/chmod /bin/busybox 0755 0 0
+ slink /bin/ln /bin/busybox 0755 0 0
+ slink /bin/mkdir /bin/busybox 0755 0 0
+ slink /bin/mknod /bin/busybox 0755 0 0
+ slink /bin/printf /bin/busybox 0755 0 0
+ file /init ${slashinit} 0755 0 0
+ SPECIALS
+ '';
+ };
+ };
+}
diff --git a/modules/jffs2.nix b/modules/jffs2.nix
@@ -0,0 +1,49 @@
+{
+ config
+, pkgs
+, lib
+, ...
+}:
+let
+ inherit (lib) mkOption types concatStringsSep;
+ inherit (pkgs) liminix callPackage writeText closureInfo;
+in
+{
+ imports = [
+ ./initramfs.nix
+ ];
+ config = {
+ kernel.config.JFFS2_FS = "y";
+ outputs = rec {
+ systemConfiguration =
+ let inherit (pkgs.pkgsBuildBuild) systemconfig;
+ in systemconfig config.filesystem.contents;
+ jffs2fs =
+ let
+ inherit (pkgs.pkgsBuildBuild) runCommand systemconfig mtdutils;
+ sysconf = systemConfiguration;
+ in runCommand "make-jffs2" {
+ depsBuildBuild = [ mtdutils ];
+ } ''
+ mkdir -p $TMPDIR/empty/nix/store/
+ cp ${sysconf}/activate $TMPDIR/empty/activate
+ pkgClosure=${closureInfo { rootPaths = [ sysconf ]; }}
+ cp $pkgClosure/registration nix-path-registration
+ grafts=$(sed < $pkgClosure/store-paths 's/^\(.*\)$/--graft \1:\1/g')
+ mkfs.jffs2 --pad --big-endian --root $TMPDIR/empty --output $out $grafts --verbose
+ '';
+ jffs2boot =
+ let o = config.outputs; in
+ pkgs.runCommand "jffs2boot" {} ''
+ mkdir $out
+ cd $out
+ ln -s ${o.jffs2fs} rootfs
+ ln -s ${o.kernel} vmlinux
+ ln -s ${o.manifest} manifest
+ ln -s ${o.initramfs} initramfs
+ '';
+
+
+ };
+ };
+}
diff --git a/pkgs/default.nix b/pkgs/default.nix
@@ -12,6 +12,7 @@
};
};
writeAshScript = callPackage ./write-ash-script {};
+ systemconfig = callPackage ./systemconfig {};
s6-init-bin = callPackage ./s6-init-bin {};
s6-rc-database = callPackage ./s6-rc-database {};
mips-vm = callPackage ./mips-vm {};
diff --git a/pkgs/mips-vm/mips-vm.sh b/pkgs/mips-vm/mips-vm.sh
@@ -1,7 +1,13 @@
#!/usr/bin/env bash
+cleanup(){
+ test -n "$rootfs" && test -f $rootfs && rm $rootfs
+}
+trap 'exit 1' INT HUP QUIT TERM ALRM USR1
+trap 'cleanup' EXIT
+
usage(){
- echo "usage: $(basename $0) [--background /path/to/state_directory] kernel rootimg"
+ echo "usage: $(basename $0) [--background /path/to/state_directory] kernel rootimg [initramfs]"
echo -e "\nWithout --background, use C-p c (not C-a c) to switch to the monitor"
exit 1
}
@@ -23,14 +29,22 @@ fi
test -n "$2" || usage
+rootfs=$(mktemp mips-vm-fs-XXXXXX)
+dd if=$2 of=$rootfs bs=65536 conv=sync
+
+if test -n "$3"; then
+ initramfs="-initrd $3"
+fi
+
INIT=${INIT-/bin/init}
echo $QEMU_OPTIONS
qemu-system-mips \
-M malta -m 256 \
-echr 16 \
- -append "liminix default console=ttyS0,38400n8 panic=10 oops=panic init=$INIT loglevel=8 root=/dev/mtdblock0 block2mtd.block2mtd=/dev/vda,4096" \
- -drive file=$2,format=raw,readonly=on,if=virtio \
+ -append "liminix default console=ttyS0,38400n8 panic=10 oops=panic init=$INIT loglevel=8 root=/dev/mtdblock0 block2mtd.block2mtd=/dev/vda,65536" \
+ -drive file=$rootfs,format=raw,readonly=on,if=virtio \
+ ${initramfs} \
-netdev socket,id=access,mcast=230.0.0.1:1234,localaddr=127.0.0.1 \
-device virtio-net-pci,disable-legacy=on,disable-modern=off,netdev=access,mac=ba:ad:1d:ea:21:02 \
-netdev socket,id=lan,mcast=230.0.0.1:1235,localaddr=127.0.0.1 \
diff --git a/pkgs/systemconfig/default.nix b/pkgs/systemconfig/default.nix
@@ -0,0 +1,60 @@
+# The ideal is that a Liminix system can boot with only the files in
+# /nix/store. This package generates a script that is run at early
+# boot (from the initramfs) to populate directories such as /etc,
+# /bin, /home according to whatever the configuration says
+# they should contain
+
+{
+ writeText
+, runCommand
+, lib
+}:
+let
+ inherit (lib.attrsets) mapAttrsToList;
+ escaped = msg : builtins.replaceStrings
+ ["\n" "=" "\"" "$" ]
+ ["\\x0a" "\\x3d" "\\x22" "\\x24"]
+ msg;
+
+ visit = prefix: attrset:
+ let makeFile = prefix : filename: {
+ type ? "f"
+ , mode ? null
+ , target ? null
+ , contents ? null
+ , file ? null
+ , major ? null
+ , minor ? null
+ }:
+ let
+ pathname = "${prefix}/${filename}";
+ chmod =
+ let m = if mode != null then mode else
+ (if type == "d" then "0755" else "0644");
+ in (if type == "s"
+ then ""
+ else "\nchmod ${m} ${pathname}");
+ cmds = {
+ "f" = "printf \"${escaped file}\" > ${pathname}";
+ "d" = "mkdir ${pathname}\n" +
+ (builtins.concatStringsSep "\n"
+ (visit pathname contents));
+ "c" = "mknod ${pathname} c ${major} ${minor}";
+ "b" = "mknod ${pathname} b ${major} ${minor}";
+ "s" = "ln -s ${target} ${pathname}";
+ "l" = "ln ${target} ${pathname}";
+ "i" = "mknod ${pathname} p";
+ };
+ cmd = cmds.${type};
+ in "${cmd}${chmod}";
+ in mapAttrsToList (makeFile prefix) attrset;
+ activateScript = attrset: writeText "systemConfig" ''
+ #!/bin/sh
+ t=$1
+ ${(builtins.concatStringsSep "\n" (visit "$t" attrset))}
+ '';
+in attrset:
+ runCommand "make-stuff" {} ''
+ mkdir -p $out
+ ln -s ${activateScript attrset} $out/activate
+ ''
