 29027fd1e1
			
		
	
	
		29027fd1e1
		
	
	
	
	
		
			
			Using pkgs.lib on the spine of module evaluation is problematic because the pkgs argument depends on the result of module evaluation. To prevent an infinite recursion, pkgs and some of the modules are evaluated twice, which is inefficient. Using ‘with lib’ prevents this problem.
		
			
				
	
	
		
			79 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Nix
		
	
	
	
	
	
			
		
		
	
	
			79 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Nix
		
	
	
	
	
	
| { config, lib, pkgs, ... }:
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| 
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| with lib;
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| 
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| let
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|   crashdump = config.boot.crashDump;
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| 
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|   kernelParams = concatStringsSep " " crashdump.kernelParams;
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| 
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| in
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| ###### interface
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| {
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|   options = {
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|     boot = {
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|       crashDump = {
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|         enable = mkOption {
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|           type = types.bool;
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|           default = false;
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|           description = ''
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|             If enabled, NixOS will set up a kernel that will
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|             boot on crash, and leave the user to a stage1 debug1devices
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|             interactive shell to be able to save the crashed kernel dump.
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|             It also activates the NMI watchdog.
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|           '';
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|         };
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|         kernelPackages = mkOption {
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|           default = pkgs.linuxPackages;
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|           # We don't want to evaluate all of linuxPackages for the manual
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|           # - some of it might not even evaluate correctly.
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|           defaultText = "pkgs.linuxPackages";
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|           example = "pkgs.linuxPackages_2_6_25";
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|           description = ''
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|             This will override the boot.kernelPackages, and will add some
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|             kernel configuration parameters for the crash dump to work.
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|           '';
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|         };
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|         kernelParams = mkOption {
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|           type = types.listOf types.str;
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|           default = [ "debug1devices" ];
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|           description = ''
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|             Parameters that will be passed to the kernel kexec-ed on crash.
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|           '';
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|         };
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|       };
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|     };
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|   };
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| 
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| ###### implementation
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| 
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|   config = mkIf crashdump.enable {
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|     boot = {
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|       postBootCommands = ''
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|         ${pkgs.kexectools}/sbin/kexec -p /run/current-system/kernel \
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|         --initrd=/run/current-system/initrd \
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|         --append="init=$(readlink -f /run/current-system/init) system=$(readlink -f /run/current-system) irqpoll maxcpus=1 reset_devices ${kernelParams}" --reset-vga --console-vga
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|       '';
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|       kernelParams = [
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|        "crashkernel=64M"
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|        "nmi_watchdog=panic"
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|        "softlockup_panic=1"
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|        "idle=poll"
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|       ];
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|       kernelPackages = mkOverride 50 (crashdump.kernelPackages // {
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|         kernel = crashdump.kernelPackages.kernel.override 
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|           (attrs: {
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|             extraConfig = (optionalString (attrs ? extraConfig) attrs.extraConfig) +
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|               ''
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|                 CRASH_DUMP y
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|                 DEBUG_INFO y
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|                 PROC_VMCORE y
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|                 LOCKUP_DETECTOR y
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|                 HARDLOCKUP_DETECTOR y
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|               '';
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|           });
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|       });
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|     };
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|   };
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| }
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