nixpkgs/modules/misc/crashdump.nix

73 lines
2.2 KiB
Nix

{pkgs, config, ...}:
with pkgs.lib;
let
crashdump = config.boot.crashDump;
kernelParams = concatStringsSep " " crashdump.kernelParams;
in
###### interface
{
options = {
boot = {
crashDump = {
enable = mkOption {
default = false;
example = true;
description = ''
If enabled, NixOS will set up a kernel that will
boot on crash, and leave the user to a stage1 debug1devices
interactive shell to be able to save the crashed kernel dump.
It also activates the NMI watchdog.
'';
};
kernelPackages = mkOption {
default = pkgs.linuxPackages;
# We don't want to evaluate all of linuxPackages for the manual
# - some of it might not even evaluate correctly.
defaultText = "pkgs.linuxPackages";
example = "pkgs.linuxPackages_2_6_25";
description = ''
This will override the boot.kernelPackages, and will add some
kernel configuration parameters for the crash dump to work.
'';
};
kernelParams = mkOption {
default = [ "debug1devices" ];
description = ''
Parameters that will be passed to the kernel kexec-ed on crash.
'';
};
};
};
};
###### implementation
config = mkIf crashdump.enable {
boot = {
postBootCommands = ''
${pkgs.kexectools}/sbin/kexec -p /run/current-system/kernel \
--initrd=/run/current-system/initrd \
--append="init=$(readlink -f /run/current-system/init) system=$(readlink -f /run/current-system) irqpoll maxcpus=1 reset_devices ${kernelParams}" --reset-vga --console-vga
'';
kernelParams = [
"crashkernel=64M"
"nmi_watchdog=1"
];
kernelPackages = mkOverride 50 (crashdump.kernelPackages // {
kernel = crashdump.kernelPackages.kernel.override
(attrs: {
extraConfig = (optionalString (attrs ? extraConfig) attrs.extraConfig) +
''
CRASH_DUMP y
DEBUG_INFO y
PROC_VMCORE y
'';
});
});
};
};
}