pyrox.dev
1{ config, lib, pkgs, ... }:
2
3with lib;
4
5let
6 crashdump = config.boot.crashDump;
7
8 kernelParams = concatStringsSep " " crashdump.kernelParams;
9
10in
11###### interface
12{
13 options = {
14 boot = {
15 crashDump = {
16 enable = mkOption {
17 type = types.bool;
18 default = false;
19 description = ''
20 If enabled, NixOS will set up a kernel that will
21 boot on crash, and leave the user to a stage1 debug1devices
22 interactive shell to be able to save the crashed kernel dump.
23 It also activates the NMI watchdog.
24 '';
25 };
26 kernelPackages = mkOption {
27 default = pkgs.linuxPackages;
28 # We don't want to evaluate all of linuxPackages for the manual
29 # - some of it might not even evaluate correctly.
30 defaultText = "pkgs.linuxPackages";
31 example = literalExample "pkgs.linuxPackages_2_6_25";
32 description = ''
33 This will override the boot.kernelPackages, and will add some
34 kernel configuration parameters for the crash dump to work.
35 '';
36 };
37 kernelParams = mkOption {
38 type = types.listOf types.str;
39 default = [ "debug1devices" ];
40 description = ''
41 Parameters that will be passed to the kernel kexec-ed on crash.
42 '';
43 };
44 };
45 };
46 };
47
48###### implementation
49
50 config = mkIf crashdump.enable {
51 boot = {
52 postBootCommands = ''
53 ${pkgs.kexectools}/sbin/kexec -p /run/current-system/kernel \
54 --initrd=/run/current-system/initrd \
55 --append="init=$(readlink -f /run/current-system/init) system=$(readlink -f /run/current-system) irqpoll maxcpus=1 reset_devices ${kernelParams}" --reset-vga --console-vga
56 '';
57 kernelParams = [
58 "crashkernel=64M"
59 "nmi_watchdog=panic"
60 "softlockup_panic=1"
61 "idle=poll"
62 ];
63 kernelPackages = mkOverride 50 (crashdump.kernelPackages // {
64 kernel = crashdump.kernelPackages.kernel.override
65 (attrs: {
66 extraConfig = (optionalString (attrs ? extraConfig) attrs.extraConfig) +
67 ''
68 CRASH_DUMP y
69 DEBUG_INFO y
70 PROC_VMCORE y
71 LOCKUP_DETECTOR y
72 HARDLOCKUP_DETECTOR y
73 '';
74 });
75 });
76 };
77 };
78}