nixpkgs/modules/system/boot/modprobe.nix
Jan Malakhovski b3f4040512 Radically change the way NixOS handles environment variables and make it possible not to use Bash as the default interactive shell.
This change does two things:

* "NixOSizes" environment variables generation. This allows some more
  error-checking and opens possibilities for a modular environment
  configuration. From now on the most of environment variables are
  generated directly by the nix code. Generating sh code that
  generates environment variables is left in a few places where
  nontrivial access to a local environment state is needed.
* By doing the first change this patch untangles bash from the
  environment configuration and makes it trivial to add a support for
  other non bash-compatible shells.

Now to the sad part. This change is quite large (and I'm not sure it's
possible to split it) and yet is not quite complete, it needs some
changes to nixpkgs to be perfect.
See !!! comments in modules/config/shells-environment.nix.

Main principle behind this change is "change environment generation
and nothing else". In particular, shell configuration principles stay
exactly the same as before.
2013-09-23 16:55:25 +00:00

113 lines
3.2 KiB
Nix

{ config, pkgs, ... }:
with pkgs.lib;
{
###### interface
options = {
system.sbin.modprobe = mkOption {
internal = true;
default = pkgs.writeTextFile {
name = "modprobe";
destination = "/sbin/modprobe";
executable = true;
text =
''
#! ${pkgs.stdenv.shell}
export MODULE_DIR=/run/current-system/kernel-modules/lib/modules
# Fall back to the kernel modules used at boot time if the
# modules in the current configuration don't match the
# running kernel.
if [ ! -d "$MODULE_DIR/$(${pkgs.coreutils}/bin/uname -r)" ]; then
MODULE_DIR=/run/booted-system/kernel-modules/lib/modules/
fi
exec ${pkgs.kmod}/sbin/modprobe "$@"
'';
};
description = ''
Wrapper around modprobe that sets the path to the modules
tree.
'';
};
boot.blacklistedKernelModules = mkOption {
default = [];
example = [ "cirrusfb" "i2c_piix4" ];
description = ''
List of names of kernel modules that should not be loaded
automatically by the hardware probing code.
'';
};
boot.extraModprobeConfig = mkOption {
default = "";
example =
''
options parport_pc io=0x378 irq=7 dma=1
'';
description = ''
Any additional configuration to be appended to the generated
<filename>modprobe.conf</filename>. This is typically used to
specify module options. See
<citerefentry><refentrytitle>modprobe.conf</refentrytitle>
<manvolnum>5</manvolnum></citerefentry> for details.
'';
type = types.lines;
};
};
###### implementation
config = {
environment.etc = singleton
{ source = pkgs.writeText "modprobe.conf"
''
${flip concatMapStrings config.boot.blacklistedKernelModules (name: ''
blacklist ${name}
'')}
${config.boot.extraModprobeConfig}
'';
target = "modprobe.d/nixos.conf";
};
environment.systemPackages = [ config.system.sbin.modprobe pkgs.kmod ];
boot.blacklistedKernelModules =
[ # This module is for debugging and generates gigantic amounts
# of log output, so it should never be loaded automatically.
"evbug"
# This module causes ALSA to occassionally select the wrong
# default sound device, and is little more than an annoyance
# on modern machines.
"snd_pcsp"
# The cirrusfb module prevents X11 from starting. FIXME:
# Ubuntu blacklists all framebuffer devices because they're
# "buggy" and cause suspend problems. Maybe we should too?
"cirrusfb"
];
system.activationScripts.modprobe =
''
# Allow the kernel to find our wrapped modprobe (which searches
# in the right location in the Nix store for kernel modules).
# We need this when the kernel (or some module) auto-loads a
# module.
echo ${config.system.sbin.modprobe}/sbin/modprobe > /proc/sys/kernel/modprobe
'';
environment.variables.MODULE_DIR.value = "/run/current-system/kernel-modules/lib/modules";
};
}