commit 6be5b90c9654c9b5194e3d72f7e08fbf809d6962
parent b2f7a429f70e121666a3e36d9c57e5b2ede480bf
Author: Daniel Barlow <dan@telent.net>
Date: Tue, 20 Sep 2022 23:04:08 +0100
boots to userland and runs busybox init
Diffstat:
6 files changed, 102 insertions(+), 28 deletions(-)
diff --git a/README.md b/README.md
@@ -8,12 +8,34 @@ Līminis + Nix
## What is this?
-This is a reboot/restart of NixWRT: a Nix-based collection of software
-tailored for domestic wifi router or IoT device devices, of the kind
-that OpenWrt or DD-WRT or Gargoyle or Tomato run on.
+This is a Nix-based collection of software tailored for domestic wifi
+router or IoT device devices, of the kind that OpenWrt or DD-WRT or
+Gargoyle or Tomato run on. It's a reboot/restart/rewrite of NixWRT.
This is not NixOS-on-your-router: it's aimed at devices that are
-underpowered for the full NixOS experience.
+underpowered for the full NixOS experience. It uses busybox tools,
+musl instead of GNU libc, and s6-rc instead of systemd.
+
+
+## Building
+
+These instructions assume you have nixpkgs checked out in a peer
+directory of this one.
+
+You need a `configuration.nix` file pointed to by `<liminix-config>`, a
+hardware device definition as argument `device`, and to choose an
+appropriate output attribute depending on what your device is and how
+you plan to install onto it. For example:
+
+ NIX_PATH=nixpkgs=../nixpkgs:$NIX_PATH NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1 nix-build -I liminix-config=./tests/smoke/configuration.nix --arg device "import ./devices/qemu.nix" -A outputs.default
+
+`outputs.default` is intended to do something appropriate for the
+device, whatever that is. For the qemu device, it creates a directory
+containing a squashfs root image and a kernel, with which you could
+then run
+
+ ./run-qemu.sh result/vmlinux result/squashfs
+
## Running tests
@@ -22,7 +44,6 @@ Assuming you have nixpkgs checked out in a peer directory of this one,
NIX_PATH=nixpkgs=../nixpkgs:$NIX_PATH ./run-tests.sh
-
## Articles of interest
* [Build Safety of Software in 28 Popular Home Routers](https://cyber-itl.org/assets/papers/2018/build_safety_of_software_in_28_popular_home_routers.pdf):
diff --git a/default.nix b/default.nix
@@ -25,5 +25,11 @@ let
in {
outputs = {
inherit squashfs kernel;
+ default = nixpkgs.pkgs.runCommand "both-kinds" {} ''
+ mkdir $out
+ cd $out
+ ln -s ${squashfs} squashfs
+ ln -s ${kernel.vmlinux} vmlinux
+ '';
};
}
diff --git a/devices/qemu.nix b/devices/qemu.nix
@@ -9,6 +9,9 @@
};
};
kernel = {
+ checkedConfig = {
+ "BINFMT_SCRIPT" = "y";
+ };
config = {
SYSVIPC= "y";
NO_HZ= "y";
@@ -343,17 +346,9 @@
UIO_CIF= "m";
EXT2_FS= "y";
EXT3_FS= "y";
- REISERFS_FS= "m";
- REISERFS_PROC_INFO= "y";
- REISERFS_FS_XATTR= "y";
- REISERFS_FS_POSIX_ACL= "y";
- REISERFS_FS_SECURITY= "y";
JFS_FS= "m";
JFS_POSIX_ACL= "y";
JFS_SECURITY= "y";
- XFS_FS= "m";
- XFS_QUOTA= "y";
- XFS_POSIX_ACL= "y";
QUOTA= "y";
QFMT_V2= "y";
FUSE_FS= "m";
@@ -366,9 +361,6 @@
PROC_KCORE= "y";
TMPFS= "y";
CONFIGFS_FS= "y";
- AFFS_FS= "m";
- HFS_FS= "m";
- HFSPLUS_FS= "m";
BEFS_FS= "m";
BFS_FS= "m";
EFS_FS= "m";
@@ -382,10 +374,10 @@
ROMFS_FS= "m";
SYSV_FS= "m";
UFS_FS= "m";
- NFS_FS= "y";
- ROOT_NFS= "y";
- NFSD= "y";
- NFSD_V3= "y";
+ # NFS_FS= "y";
+ # ROOT_NFS= "y";
+ # NFSD= "y";
+ # NFSD_V3= "y";
NLS_CODEPAGE_437= "m";
NLS_CODEPAGE_737= "m";
NLS_CODEPAGE_775= "m";
@@ -444,6 +436,13 @@
CRYPTO_TWOFISH= "m";
RCU_CPU_STALL_TIMEOUT = "60";
ENABLE_DEFAULT_TRACERS = "y";
+
+
+ SQUASHFS = "y";
+ SQUASHFS_XZ = "y";
+ VIRTIO_PCI = "y";
+ VIRTIO_BLK = "y";
+ VIRTIO_NET = "y";
};
};
}
diff --git a/make-image.nix b/make-image.nix
@@ -1,6 +1,14 @@
pkgs: config:
let
- inherit (pkgs) callPackage stdenvNoCC closureInfo stdenv writeText s6-rc;
+ inherit (pkgs)
+ callPackage
+ closureInfo
+ runCommand
+ s6-rc
+ stdenv
+ stdenvNoCC
+ writeScript
+ writeText;
# we need to generate s6 db, by generating closure of all
# config.services and calling s6-rc-compile on them
@@ -28,8 +36,46 @@ let
s6-rc-compile $out/compiled $srcs
'';
};
- makeSquashfs = callPackage <nixpkgs/nixos/lib/make-squashfs.nix> {
- storeContents = [ s6db ] ++ config.packages ;
+ rcS = writeScript "rcS" ''
+ #!${pkgs.pkgsStatic.busybox}/bin/sh
+ echo WHEEEE
+ PATH=${pkgs.pkgsStatic.busybox}/bin:$PATH
+ export PATH
+ mount -t devtmpfs none /dev/
+ mount -t devpts none /dev/pts
+ mount -t proc none /proc
+ mkdir -p /run/services
+ '';
+ storefs = callPackage <nixpkgs/nixos/lib/make-squashfs.nix> {
+ storeContents = [ rcS pkgs.pkgsStatic.busybox s6db pkgs.s6-linux-init ] ++ config.packages ;
# comp = "xz -Xdict-size 100%"
};
-in makeSquashfs
+ pseudofiles = writeText "pseudofiles" ''
+ / d 0755 0 0
+ /bin d 0755 0 0
+ /etc d 0755 0 0
+ /run d 0755 0 0
+ /dev d 0755 0 0
+ /dev/console c 0600 root root 5 1
+ /dev/null c 0666 root root 1 3
+ /dev/tty c 0777 root root 5 0
+ /dev/tty1 c 0777 root root 4 1
+ /dev/tty2 c 0777 root root 4 2
+ /dev/tty3 c 0777 root root 4 3
+ /dev/tty4 c 0777 root root 4 4
+ /dev/zero c 0666 root root 1 5
+ /proc d 0555 root root
+ /dev/pts d 0755 0 0
+ /etc/init.d d 0755 0 0
+ /bin/init s 0755 0 0 ${pkgs.pkgsStatic.busybox}/bin/init
+ /bin/sh s 0755 0 0 ${pkgs.pkgsStatic.busybox}/bin/sh
+ /bin/busybox s 0755 0 0 ${pkgs.pkgsStatic.busybox}/bin/busybox
+ /etc/init.d/rcS s 0755 0 0 ${rcS}
+ '';
+in runCommand "frob-squashfs" {} ''
+ cp ${storefs} ./store.img
+ chmod +w store.img
+ ${pkgs.buildPackages.squashfsTools}/bin/mksquashfs - store.img -no-recovery -quiet -no-progress -root-becomes store -p "/ d 0755 0 0"
+ ${pkgs.buildPackages.squashfsTools}/bin/mksquashfs - store.img -no-recovery -quiet -no-progress -root-becomes nix -pf ${pseudofiles}
+ cp store.img $out
+''
diff --git a/make-kernel.nix b/make-kernel.nix
@@ -24,6 +24,6 @@ in
{
vmlinux = callPackage ./make-vmlinux.nix {
inherit tree;
- config = config.kernel.config;
+ inherit (config.kernel) config;# checkedConfig;
};
}
diff --git a/run-qemu.sh b/run-qemu.sh
@@ -1,6 +1,8 @@
#!/usr/bin/env nix-shell
#! nix-shell -i bash -p qemu
-qemu-system-mips -M malta -m 256 \
- -append "earlyprintk=serial,ttyS0 console=ttyS0,38400n8 panic=10 oops=panic init=/bin/init loglevel=8 root=/dev/vda" \
- -kernel $1 -nographic -display none -serial mon:stdio
+qemu-system-mips \
+ -M malta -m 256 \
+ -append "earlyprintk=serial,ttyS0 console=ttyS0,38400n8 panic=10 oops=panic init=/bin/init loglevel=8 root=/dev/vda" \
+ -drive file=$2,format=raw,readonly,if=virtio \
+ -kernel $1 -nographic -display none -serial mon:stdio
