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mirror of https://github.com/NixOS/mobile-nixos.git synced 2024-12-17 04:51:31 +03:00
mobile-nixos/modules/initrd-shell.nix
Samuel Dionne-Riel bdd234fc0e initrd-shell: Allows using a shell on failure...
This needs to be plugged into the init via duck-typing.
2020-02-03 16:19:10 -05:00

73 lines
1.9 KiB
Nix

{ config, lib, pkgs, ... }:
let
inherit (lib) mkMerge mkIf mkOption types;
cfg = config.mobile.boot.stage-1.shell;
in
{
options.mobile.boot.stage-1.shell = {
enable = mkOption {
type = types.bool;
default = false;
description = ''
Enables a shell before switching root.
This shell (as currently configured) will not allow switching root.
'';
};
console = mkOption {
type = types.str;
default = "console";
description = ''
Selects the /dev/___ device to use.
Use `ttyS0` for serial, `tty1` for first VT or keep the default to `console`
for the last defined `console=` kernel parameter.
'';
};
shellOnFail = mkOption {
type = types.bool;
default = false;
description = ''
Enables a shell on failures.
'';
};
};
config.mobile.boot.stage-1 = mkMerge [
(mkIf (cfg.enable || cfg.shellOnFail) {
tasks = [
(pkgs.writeText "system-shell.rb" ''
module System
def self.shell()
cmd = %q{setsid /bin/sh -c /bin/sh < /dev/${cfg.console} >/dev/${cfg.console} 2>/dev/${cfg.console}}
$logger.debug(" $ #{cmd}")
puts("\nExit this shell (CTRL+D) to resume booting.\n")
system(cmd)
end
end
'')
];
})
(mkIf cfg.enable {
tasks = [
(pkgs.writeText "run-shell-task.rb" ''
class Tasks::RunShell < SingletonTask
def initialize()
# Wedge the task between the target "root", and the
# actual task we want to prevent running.
add_dependency(:Target, :SwitchRoot)
Tasks::SwitchRoot.instance.add_dependency(:Task, self)
end
def run()
System.shell()
end
end
'')
];
})
];
}