chore: rootfs pkg

rootfs/default.nix

@@ -0,0 +1,30 @@
+{
+  pkgs,
+  stdenvNoCC,
+  patosPkgs,
+  ...
+}:
+let
+  version = "0.0.1";
+  pname = "patos-rootfs";
+in
+stdenvNoCC.mkDerivation (finalAttrs: {
+  inherit version;
+  inherit pname;
+
+  buildInputs = with pkgs; [
+    glibc
+    binutils
+  ];
+
+  glibcPatos = patosPkgs.glibc.out;
+  systemd = patosPkgs.systemd.out;
+  dbusBroker = patosPkgs.dbus-broker.out;
+  kernel = patosPkgs.kernel.kernel;
+  busybox = pkgs.busybox.out;
+  kmodLibs = pkgs.kmod.lib;
+  kmodBin = pkgs.kmod.out;
+  libbpf = pkgs.libbpf.out;
+
+  builder = ./mkrootfs.sh;
+})

rootfs/mkrootfs.sh

@@ -0,0 +1,54 @@
+set -ex -o pipefail
+
+mkdir -p $out
+mkdir -p $out/etc $out/dev $out/proc $out/sys $out/tmp $out/root
+ln -sf ../usr/bin $out/bin
+ln -sf ../usr/bin $out/sbin
+ln -sf ../usr/lib $out/lib
+ln -sf ../usr/lib $out/lib64
+ln -sf ../proc/self/mounts $out/etc/mtab
+
+### install systemd
+echo "Installing systemd"
+cp -Pr $systemd/* $out/
+find $out -type d -exec chmod 755 {} \;
+rm -rf $out/usr/include
+rm -rf $out/usr/sbin
+rm -f $out/usr/lib/systemd/system/sysinit.target.wants/systemd-firstboot.service
+# remove vconsole setup
+rm -f $out/usr/lib/udev/rules.d/90-vconsole.rules
+
+### install PatOS glibc
+cp -P $glibcPatos/lib/*.so* $out/usr/lib/
+
+### install kernel modules
+cp -r $kernel/lib/modules $out/usr/lib/
+find $out/usr/lib/modules -type d -exec chmod 755 {} \;
+
+### install busybox
+cp $busybox/bin/busybox $out/usr/bin/
+$out/usr/bin/busybox --list | xargs -I {} ln -sf busybox $out/usr/bin/{}
+
+### install dbus broker
+cp -r $dbusBroker/* $out/
+
+### install lib kmod
+cp -P $kmodLibs/lib/* $out/usr/lib
+cp -P $kmodBin/bin/* $out/usr/bin
+
+### install libbpf
+cp -P $libbpf/lib/libbpf* $out/usr/lib
+
+### Find and install all shared libs
+find $out -type f -executable -exec ldd {} \; | awk '{print $3}' | grep -v systemd | grep -v glibc | sort -u | xargs cp -t $out/usr/lib
+find $out -type f -executable -exec chmod 755 {} \;
+
+# FIXME: ELF patching. Is there a better way?
+find $out -type f -executable -exec patchelf --set-rpath /lib:/usr/lib:/usr/lib/systemd {} \;
+find $out -type f -executable -exec patchelf --set-interpreter /lib/ld-linux-x86-64.so.2 {} \;
+patchelf --remove-rpath $out/usr/lib/ld-linux-x86-64.so.2
+
+# strip binaries
+find $out -type f -executable -exec strip {} \;
+find $out -type d -exec chmod 755 {} \;
+