liminix/modules/kexecboot.nix

64 lines
1.8 KiB
Nix
Raw Normal View History

{
config
, pkgs
, lib
, ...
}:
let
inherit (lib) mkOption mkForce types concatStringsSep;
in {
imports = [ ./ramdisk.nix ];
options.system.outputs = {
kexecboot = mkOption {
type = types.package;
description = ''
Directory containing files needed for kexec booting.
Can be copied onto the target device using ssh or similar
'';
};
boot-sh = mkOption {
type = types.package;
description = ''
Shell script to run on the target device that invokes
kexec with appropriate options
'';
};
};
config = {
boot.ramdisk.enable = true;
system.outputs = {
kexecboot =
let o = config.system.outputs; in
pkgs.runCommand "kexecboot" {} ''
mkdir $out
cd $out
ln -s ${o.rootfs} rootfs
ln -s ${o.kernel} kernel
ln -s ${o.manifest} manifest
ln -s ${o.boot-sh} boot.sh
ln -s ${pkgs.kexec-tools-static}/bin/kexec ./kexec
ln -s ${o.dtb} dtb
'';
boot-sh =
let
inherit (pkgs.lib.trivial) toHexString;
inherit (config.system.outputs) rootfs kernel;
cmdline = concatStringsSep " " config.boot.commandLine;
in
pkgs.buildPackages.runCommand "boot.sh.sh" {
} ''
rootfsStart=${toString (100 * 1024 * 1024)}
rootfsBytes=$(stat -L -c %s ${rootfs})
append_cmd="mtdparts=phram0:''${rootfsBytes}(rootfs) phram.phram=phram0,''${rootfsStart},''${rootfsBytes} memmap=''${rootfsBytes}\$''${rootfsStart}";
cat > $out <<EOF
#!/bin/sh
test -d \$1
cd \$1
./kexec -f -d --map-file rootfs@$rootfsStart --dtb dtb --command-line '${cmdline} $append_cmd' kernel
EOF
'';
};
};
}