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 type = types.package;
28 default = pkgs.linuxPackages;
29 # We don't want to evaluate all of linuxPackages for the manual
30 # - some of it might not even evaluate correctly.
31 defaultText = "pkgs.linuxPackages";
32 example = literalExample "pkgs.linuxPackages_2_6_25";
33 description = ''
34 This will override the boot.kernelPackages, and will add some
35 kernel configuration parameters for the crash dump to work.
36 '';
37 };
38 kernelParams = mkOption {
39 type = types.listOf types.str;
40 default = [ "debug1devices" ];
41 description = ''
42 Parameters that will be passed to the kernel kexec-ed on crash.
43 '';
44 };
45 };
46 };
47 };
48
49###### implementation
50
51 config = mkIf crashdump.enable {
52 boot = {
53 postBootCommands = ''
54 ${pkgs.kexectools}/sbin/kexec -p /run/current-system/kernel \
55 --initrd=/run/current-system/initrd \
56 --append="init=$(readlink -f /run/current-system/init) system=$(readlink -f /run/current-system) irqpoll maxcpus=1 reset_devices ${kernelParams}" --reset-vga --console-vga
57 '';
58 kernelParams = [
59 "crashkernel=64M"
60 "nmi_watchdog=panic"
61 "softlockup_panic=1"
62 "idle=poll"
63 ];
64 kernelPackages = mkOverride 50 (crashdump.kernelPackages // {
65 kernel = crashdump.kernelPackages.kernel.override
66 (attrs: {
67 extraConfig = (optionalString (attrs ? extraConfig) attrs.extraConfig) +
68 ''
69 CRASH_DUMP y
70 DEBUG_INFO y
71 PROC_VMCORE y
72 LOCKUP_DETECTOR y
73 HARDLOCKUP_DETECTOR y
74 '';
75 });
76 });
77 };
78 };
79}