From 344f0f271daac9ad77c5b1da2ed59c3a3e394e13 Mon Sep 17 00:00:00 2001
From: Wynn Wolf Arbor
Date: Thu, 4 Jun 2020 14:50:18 +0200
Subject: Use configuration file under /boot instead of /proc/config.gz

kern(1) has been using /proc/config.gz as the source of the currently
running kernel's config since its initial commit. Whilst this location
is convenient because of its static nature, it does need a specific
kernel option, IKCONFIG_PROC, to be set.

Furthermore, it introduces a dependency on gzip(1) to decompress the
file on the fly. Consequently, we need to stream gzip's output to
commands or save it in a temporary file to access it neatly.

Since Gentoo's default install script for the kernel, installkernel(8),
places each kernel's configuration file in /boot, we can use this
location to retrieve the currently running kernel's configuration
instead and work around all of the above limitations.

Of course we need to make sure that /boot is mounted before we try
accessing any configuration files on there. We use the already existing
code from install_kernel() for that.
---
 kern.1 | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

(limited to 'kern.1')

diff --git a/kern.1 b/kern.1
index 79dcad2..ac3e4e2 100644
--- a/kern.1
+++ b/kern.1
@@ -1,4 +1,4 @@
-.Dd May 16, 2020
+.Dd June 4, 2020
 .Dt KERN 1
 .Os
 .Sh NAME
@@ -103,9 +103,8 @@ to display the differences between the generated kernel configuration and
 .Pp
 If no config is given, this command compares against the configuration of the currently
 running kernel.
-This requires
-.Sy IKCONFIG_PROC
-to be enabled.
+This requires the configuration file to be present under
+.Pa /boot .
 .It Sy build
 Builds the selected kernel.
 .It Sy install
-- 
cgit v1.2.3-2-gb3c3