Commit 24941111 authored Apr 10, 2026 by Markus Theil

kernel: enable CONFIG_HW_RANDOM to be built-in



Starting with kernels around 6.18 and 6.19 I noticed,
that /dev/hwrng was no longer present and the TPM 2.0
usually found in modern computers did therefore not automatically
seed the kernel RNG with the hw random subsystem.

Enabling CONFIG_HW_RANDOM to yes fixes this. The subsystem
is rather small and should not increase the default kernel size
too much.

Signed-off-by: Markus Theil <theil.markus@gmail.com>

parent 23c0b3ec

pkgs/os-specific/linux/kernel/common-config.nix

+2 −0

Original line number	Diff line number	Diff line
		@@ -825,6 +825,8 @@ let
		whenOlder "6.2" yes
		); # allow RDRAND to seed the RNG
		RANDOM_TRUST_BOOTLOADER = whenOlder "6.2" yes; # allow the bootloader to seed the RNG
		# only when compiled as yes, TPM 2.0 will automatically seed the kernel RNG
		HW_RANDOM = yes;

		MODULE_SIG = no; # r13y, generates a random key during build and bakes it in
		# Depends on MODULE_SIG and only really helps when you sign your modules

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