Find the time now at any town or city Worldwide from the command line in Gentoo Linux

In my hunt for a command to return the current time at any town or city in the World, I recently found a Perl script now.pl posted in 2012 by Jim Monty on grokbase. The script uses a Perl module to access the database of the GeoNames Web site. To use the module you need to have a user account at the GeoNames Web site and be connected to the Internet. The script also uses the modules URI::Escape and DateTime.

In the case of Gentoo Linux, ebuilds for some of the Perl modules used by now.pl are not available in the main Portage tree, so I installed them from a Portage local overlay, as explained below.

First I created in my local overlay an ebuild for the Perl module Geo::GeoNames and then merged it:

# mkdir -p /usr/local/portage/dev-perl/Geo-GeoNames
# cd /usr/local/portage/dev-perl/Geo-GeoNames
# nano -w Geo-GeoNames-1.01.ebuild
# ebuild Geo-GeoNames-1.01.ebuild manifest
# emerge --ask Geo-GeoNames

The ebuild Geo-GeoNames-1.01.ebuild I created is listed below:

EAPI=5

MODULE_AUTHOR=BDFOY
inherit perl-module

DESCRIPTION="Provides a perl interface to the webservices found at http://api.geonames.org"

SLOT="0"
KEYWORDS="alpha amd64 ~arm hppa ia64 ~mips ppc ppc64 ~s390 ~sh sparc x86 ~amd64-linux ~x86-linux ~ppc-macos ~x86-macos ~sparc-solaris"
IUSE=""

RDEPEND="
        dev-perl/Module-Build
        "
DEPEND="${RDEPEND}"

SRC_TEST=do

I’m not sure if I declared the correct dependencies in DEPEND and RDEPEND, but the Geo::GeoNames module is merged in my installation and functions correctly.

The Perl script also uses the Perl module URI::Escape, which I found out is part of the package dev-perl/URI in the Portage main tree and was already installed, so I did not need to do anything further as far as that was concerned.

Next I needed to install the Perl module Date::Time. Fortunately there is an ebuild for dev-perl/DateTime in the main Portage tree, so I merged that package directly:

# emerge --ask DateTime

Then I surfed to the GeoNames Web site and registered for a user account. My thanks go to the people who provide and maintain the site and database.

I then created a file /home/fitzcarraldo/now.pl containing the Perl script listed in Jim Monty’s post of Aug 19, 2012 on the Web page: [DateTime] Is there timezone data for any Indian cities such as Mumbai, Dehli, &c.?. My thanks also go to Jim Monty for posting his script.

My initial attempts at running now.pl resulted in an error message warning about a missing Mojo::UserAgent Perl module. I therefore needed to install the package Mojolicious but, unfortunately, the main Portage tree does not have an ebuild for it. I could have either added a third-party overlay (e.g. srcshelton) which contains a Mojolicious ebuild or downloaded the ebuild and put it in my local overlay. I opted for the latter, and merged it:

# mkdir -p /usr/local/portage/dev-perl/Mojolicious
# cd /usr/local/portage/dev-perl/Mojolicious
# cp /home/fitzcarraldo/Downloads/Mojolicious-5.30.ebuild .
# ebuild Mojolicious-5.30.ebuild manifest
# emerge --ask Mojolicious

Despite the examples given in Jim Monty’s post using now.pl with place names containing diacritics, in my case the script could not handle them, so I made a couple of small modifications, and the script I’m using is show below:

#!perl
use strict;
use warnings;

use DateTime;
use Geo::GeoNames;
use URI::Escape;
use Encode;

binmode STDOUT, ':encoding(UTF-8)';

my $city = decode("UTF-8", @ARGV ? shift : 'London');

my $geo = Geo::GeoNames->new( username => '***********' );
# N.B. Replace the asterisks with your GeoNames user name.

my $result = $geo->search(
q       => uri_escape_utf8($city),
maxRows => 1,
style   => 'FULL'
);

defined $result->[0] or die "Unrecognized city '$city'\n";

my $city_name    = $result->[0]->{name};
my $country_name = $result->[0]->{countryName};
my $time_zone    = $result->[0]->{timezone}{content};
my $time_now     = DateTime->now( time_zone => $time_zone );

print "$city_name ($country_name) $time_now ($time_zone)\n";

exit 0;

I made the script executable and ensured my user account could use it:

# chmod +x /home/fitzcarraldo/now.pl
# chown fitzcarraldo:fitzcarraldo /home/fitzcarraldo/now.pl

Now if I enter the name of a town or city anywhere in the World while my laptop is connected to the Internet, the script prints the town/city name, country, local time and the time zone’s name as given in the zoneinfo database (a.k.a. ‘Olsen database’, ‘tz database‘ and ‘IANA time zone database’):

$ cd
$ perl now.pl
London (United Kingdom) 2015-09-25T23:10:16 (Europe/London)
$ perl now.pl "London Canada"
London (Canada) 2015-09-25T18:10:22 (America/Toronto)
$ perl now.pl Paris
Paris (France) 2015-09-26T00:10:29 (Europe/Paris)
$ perl now.pl "New York"
New York (United States) 2015-09-25T18:10:41 (America/New_York)
$ perl now.pl Tokyo
Tokyo (Japan) 2015-09-26T07:10:50 (Asia/Tokyo)
$ perl now.pl "Mexico City"
Mexico City (Mexico) 2015-09-25T17:10:59 (America/Mexico_City)
$ perl now.pl "Kuala Lumpur"
Kuala Lumpur (Malaysia) 2015-09-26T06:11:09 (Asia/Kuala_Lumpur)
$ perl now.pl "São Paulo"
São Paulo (Brazil) 2015-09-25T19:11:29 (America/Sao_Paulo)
$ perl now.pl Maceio
Maceió (Brazil) 2015-09-25T19:11:39 (America/Maceio)
$ perl now.pl Maceió
Maceió (Brazil) 2015-09-25T19:11:48 (America/Maceio)
$ perl now.pl "Várzea Grande"
Várzea Grande (Brazil) 2015-09-25T18:12:04 (America/Cuiaba)
$ perl now.pl "Mos Eisley"
Unrecognized city 'Mos Eisley'

now.pl works by first using the Geo::GeoNames module to look up in the GeoNames database via the Internet the time zone for the town/city you have specified, then using the Date::Time module to look up the time in that time zone from the zoneinfo data in your installation, based on the time now in your installation’s system clock. In other words, if your system clock is, for example, 3 minutes ahead of actual time then the time returned by now.pl for the relevant time zone would also be 3 minutes fast. But if your system clock is correct, the script would return an accurate time for the requested town/city.

My interest in finding a command that returns the current time at any town or city around the Globe was because I wanted to create a keyboard shortcut to insert a signature in my e-mails, displaying my current location and the local time wherever I happened to be (I have to travel internationally frequently because of my work). In my next post I will explain how I created such an e-mail signature.

Gentoo Linux: Run a script at shutdown, but not when rebooting

In Gentoo Linux it is straightforward to run scripts automatically when the OS starts (boots) and stops (either shutting down or rebooting). You simply need to place an executable script file in the directory /etc/local.d/ with the suffix ‘.start‘ or ‘.stop‘, depending on whether you want the script to run at the beginning or end of your Linux session. The file /etc/local.d/README (complete with ‘sequentially’ misspelt) explains it better:

This directory should contain programs or scripts which are to be run
when the local service is started or stopped.

If a file in this directory is executable and it has a .start extension,
it will be run when the local service is started. If a file is
executable and it has a .stop extension, it will be run when the local
service is stopped.

All files are processed in lexical order.

Keep in mind that files in this directory are processed sequencially,
and the local service is not considered started or stopped until
everything is processed, so if you have a process which takes a long
time to run, it can delay your boot or shutdown processing.

Scripts with a ‘.stop‘ suffix are launched both when you shutdown your Linux installation and when you reboot it. However, sometimes you may not want to run a script when you reboot your installation. A typical example would be a script to backup your hard drive; you would probably only want it to run when you have finished for the day and you are shutting down and powering off your machine. So, how do you achieve that? I initially thought I would be able to use the ‘runlevel‘ command or the RUNLEVEL environment variable in a script (see man runlevel regarding both). But I could not get my script /etc/local.d/10-run_on_shutdown.stop to work using either. However, the command ‘who -r‘ (‘who --runlevel‘) does work for me in Gentoo Linux with OpenRC:

$ cat /etc/local.d/10-run_on_shutdown.stop
#!/bin/bash
if [ `who -r | awk '{print $2}'` = "0" ]; then
  echo "shutting down" >> /home/fitzcarraldo/test.txt
  date >> /home/fitzcarraldo/test.txt
elif [ `who -r | awk '{print $2}'` = "6" ]; then
  echo "rebooting" >> /home/fitzcarraldo/test.txt
  date >> /home/fitzcarraldo/test.txt
else
  echo "neither rebooting nor shutting down" >> /home/fitzcarraldo/test.txt
  date >> /home/fitzcarraldo/test.txt
fi
$

After rebooting, then shutting down and booting, then rebooting again, the contents of the file test.txt show that the above-mentioned simple script works as intended:

$ cat test.txt
rebooting
Sun  6 Sep 12:42:11 BST 2015
shutting down
Sun  6 Sep 12:46:04 BST 2015
rebooting
Sun  6 Sep 12:49:31 BST 2015
$

So the following script /etc/local.d/10-run_on_shutdown.stop will do the desired job:

$ cat /etc/local.d/10-run_on_shutdown.stop
#!/bin/bash
if [ `who -r | awk '{print $2}'` = "0" ]; then
  ######################################################################
  # Put Bash commands here to be executed on shutdown but not on reboot.
  ######################################################################
fi
$

Don’t forget to make the script executable:

# chmod +x /etc/local.d/10-run_on_shutdown.stop

Gentoo Linux installations without initramfs: Updating Intel CPU microcode

This post explains how I configured the Gentoo Linux (amd64) installation on my Clevo W230SS laptop to make it update the Intel CPU microcode using the kernel Microcode Early Update driver.

Back in April I installed Gentoo Linux Stable and built the kernel using the default manual configuration steps given in the Gentoo Handbook, and my installation therefore did not use an initramfs. The contents of the /boot directory were as listed below:

# ls -1 /boot
System.map-3.18.11-gentoo
config-3.18.11-gentoo
grub
lost+found
vmlinuz-3.18.11-gentoo

Contrast the above with the boot directory of the Gentoo Linux Testing (~amd64) installation on my Compal NBLB2 laptop, which does use an initramfs because I built the kernel using the optional genkernel utility:

# ls -1 /boot
System.map-genkernel-x86_64-3.18.11-gentoo
boot
grub
initramfs-genkernel-x86_64-3.18.11-gentoo
kernel-genkernel-x86_64-3.18.11-gentoo
lost+found

Since I wrote my earlier post on updating CPU microcode, the use of a kernel module and initscript to update CPU microcode has been dropped (in Gentoo Linux, at least). This is because updating CPU microcode relatively late in the boot process may cause problems if some processes have started before the update has taken place. The only safe way to update CPU microcode is to use the kernel’s built-in Microcode Early Update driver (METHOD 2 in my earlier post).

Now, new versions of the relevant Gentoo Linux ebuilds (microcode-ctl-1.28-r1, microcode-data-20150121-r1 and iucode_tool-1.3) have recently been released (see Gentoo Bug Report No. 528712). If a Gentoo Linux installation does not use an initramfs, the microcode-data ebuild now includes an ‘initramfs‘ USE flag which you can set in order to create a minimal initramfs to load the CPU microcode at boot. Below I explain in detail how I configured my installation to update the CPU microcode early during boot.

Before doing anything at all, I checked the microcode version for my CPU (Intel Core i7-4810MQ @ 2.80GHz):

# grep microcode /proc/cpuinfo
microcode   : 0x12
microcode   : 0x12
microcode   : 0x12
microcode   : 0x12
microcode   : 0x12
microcode   : 0x12
microcode   : 0x12
microcode   : 0x12
# dmesg | grep microcode
[    0.262544] microcode: CPU0 sig=0x306c3, pf=0x10, revision=0x12
[    0.262641] microcode: CPU1 sig=0x306c3, pf=0x10, revision=0x12
[    0.262740] microcode: CPU2 sig=0x306c3, pf=0x10, revision=0x12
[    0.262841] microcode: CPU3 sig=0x306c3, pf=0x10, revision=0x12
[    0.262939] microcode: CPU4 sig=0x306c3, pf=0x10, revision=0x12
[    0.263038] microcode: CPU5 sig=0x306c3, pf=0x10, revision=0x12
[    0.263138] microcode: CPU6 sig=0x306c3, pf=0x10, revision=0x12
[    0.263236] microcode: CPU7 sig=0x306c3, pf=0x10, revision=0x12
[    0.263367] microcode: Microcode Update Driver: v2.00 , Peter Oruba

Fortunately I did not need to rebuild the kernel as I had already configured it back in April when I installed Gentoo, with a view to implementing early microcode updating at some point:

# grep CONFIG_BLK_DEV_INITRD /usr/src/linux/.config
CONFIG_BLK_DEV_INITRD=y
# grep CONFIG_MICROCODE /usr/src/linux/.config
CONFIG_MICROCODE=y
CONFIG_MICROCODE_INTEL=y
# CONFIG_MICROCODE_AMD is not set
CONFIG_MICROCODE_OLD_INTERFACE=y
CONFIG_MICROCODE_INTEL_EARLY=y
# CONFIG_MICROCODE_AMD_EARLY is not set
CONFIG_MICROCODE_EARLY=y
# grep CONFIG_INITRAMFS_SOURCE /usr/src/linux/.config
CONFIG_INITRAMFS_SOURCE=""

Then I set the initramfs USE flag and unmasked the ~amd64 ebuilds created by Gentoo developer SpanKY (microcode-ctl-1.28-r1.ebuild, microcode-data-20150121-r1.ebuild and iucode_tool-1.3.ebuild) as discussed in the above-mentioned Gentoo bug report:

# cat /etc/portage/package.use/microcode-data
sys-apps/microcode-data initramfs
# cat /etc/portage/package.accept_keywords/microcode-data
sys-apps/microcode-data ~amd64
sys-apps/iucode_tool ~amd64
# cat /etc/portage/package.accept_keywords/microcode-ctl
sys-apps/microcode-ctl ~amd64

Then I merged the packages:

# emerge --ask microcode-ctl microcode-data

This resulted in the following files:

# ls -la /lib/firmware/microcode.cpio
-rw-r--r-- 1 root root 663552 Aug 26 15:06 /lib/firmware/microcode.cpio
# ls -la /lib/firmware/intel-ucode
total 768
drwxr-xr-x  2 root root  4096 Aug 26 15:06 .
drwxr-xr-x 62 root root 16384 Aug 26 15:06 ..
-rw-r--r--  1 root root  2048 Aug 26 15:06 06-03-02
-rw-r--r--  1 root root  6144 Aug 26 15:06 06-05-00
-rw-r--r--  1 root root  2048 Aug 26 15:06 06-05-01
-rw-r--r--  1 root root  6144 Aug 26 15:06 06-05-02
-rw-r--r--  1 root root  8192 Aug 26 15:06 06-05-03
-rw-r--r--  1 root root  2048 Aug 26 15:06 06-06-00
-rw-r--r--  1 root root  2048 Aug 26 15:06 06-06-05
-rw-r--r--  1 root root  6144 Aug 26 15:06 06-06-0a
-rw-r--r--  1 root root  6144 Aug 26 15:06 06-06-0d
-rw-r--r--  1 root root  2048 Aug 26 15:06 06-07-01
-rw-r--r--  1 root root  2048 Aug 26 15:06 06-07-02
-rw-r--r--  1 root root  2048 Aug 26 15:06 06-07-03
-rw-r--r--  1 root root 10240 Aug 26 15:06 06-08-01
-rw-r--r--  1 root root  4096 Aug 26 15:06 06-08-03
-rw-r--r--  1 root root 10240 Aug 26 15:06 06-08-06
-rw-r--r--  1 root root  6144 Aug 26 15:06 06-08-0a
-rw-r--r--  1 root root  6144 Aug 26 15:06 06-09-05
-rw-r--r--  1 root root  2048 Aug 26 15:06 06-0a-00
-rw-r--r--  1 root root  2048 Aug 26 15:06 06-0a-01
-rw-r--r--  1 root root  4096 Aug 26 15:06 06-0b-01
-rw-r--r--  1 root root  4096 Aug 26 15:06 06-0b-04
-rw-r--r--  1 root root  2048 Aug 26 15:06 06-0d-06
-rw-r--r--  1 root root  4096 Aug 26 15:06 06-0e-08
-rw-r--r--  1 root root  8192 Aug 26 15:06 06-0e-0c
-rw-r--r--  1 root root  8192 Aug 26 15:06 06-0f-02
-rw-r--r--  1 root root 12288 Aug 26 15:06 06-0f-06
-rw-r--r--  1 root root  8192 Aug 26 15:06 06-0f-07
-rw-r--r--  1 root root  4096 Aug 26 15:06 06-0f-0a
-rw-r--r--  1 root root 28672 Aug 26 15:06 06-0f-0b
-rw-r--r--  1 root root 12288 Aug 26 15:06 06-0f-0d
-rw-r--r--  1 root root 12288 Aug 26 15:06 06-16-01
-rw-r--r--  1 root root 20480 Aug 26 15:06 06-17-06
-rw-r--r--  1 root root  4096 Aug 26 15:06 06-17-07
-rw-r--r--  1 root root 24576 Aug 26 15:06 06-17-0a
-rw-r--r--  1 root root 14336 Aug 26 15:06 06-1a-04
-rw-r--r--  1 root root 10240 Aug 26 15:06 06-1a-05
-rw-r--r--  1 root root 15360 Aug 26 15:06 06-1c-02
-rw-r--r--  1 root root 20480 Aug 26 15:06 06-1c-0a
-rw-r--r--  1 root root  4096 Aug 26 15:06 06-1d-01
-rw-r--r--  1 root root  6144 Aug 26 15:06 06-1e-04
-rw-r--r--  1 root root  7168 Aug 26 15:06 06-1e-05
-rw-r--r--  1 root root  8192 Aug 26 15:06 06-25-02
-rw-r--r--  1 root root  3072 Aug 26 15:06 06-25-05
-rw-r--r--  1 root root 10240 Aug 26 15:06 06-26-01
-rw-r--r--  1 root root 10240 Aug 26 15:06 06-2a-07
-rw-r--r--  1 root root 16384 Aug 26 15:06 06-2d-06
-rw-r--r--  1 root root 17408 Aug 26 15:06 06-2d-07
-rw-r--r--  1 root root 13312 Aug 26 15:06 06-2f-02
-rw-r--r--  1 root root 12288 Aug 26 15:06 06-3a-09
-rw-r--r--  1 root root 21504 Aug 26 15:06 06-3c-03
-rw-r--r--  1 root root 14336 Aug 26 15:06 06-3d-04
-rw-r--r--  1 root root 13312 Aug 26 15:06 06-3e-04
-rw-r--r--  1 root root 11264 Aug 26 15:06 06-3e-06
-rw-r--r--  1 root root 15360 Aug 26 15:06 06-3e-07
-rw-r--r--  1 root root 28672 Aug 26 15:06 06-3f-02
-rw-r--r--  1 root root 20480 Aug 26 15:06 06-45-01
-rw-r--r--  1 root root 23552 Aug 26 15:06 06-46-01
-rw-r--r--  1 root root  4096 Aug 26 15:06 0f-00-07
-rw-r--r--  1 root root  6144 Aug 26 15:06 0f-00-0a
-rw-r--r--  1 root root  2048 Aug 26 15:06 0f-01-02
-rw-r--r--  1 root root  6144 Aug 26 15:06 0f-02-04
-rw-r--r--  1 root root  8192 Aug 26 15:06 0f-02-05
-rw-r--r--  1 root root  2048 Aug 26 15:06 0f-02-06
-rw-r--r--  1 root root  6144 Aug 26 15:06 0f-02-07
-rw-r--r--  1 root root  6144 Aug 26 15:06 0f-02-09
-rw-r--r--  1 root root  2048 Aug 26 15:06 0f-03-02
-rw-r--r--  1 root root  2048 Aug 26 15:06 0f-03-03
-rw-r--r--  1 root root  7168 Aug 26 15:06 0f-03-04
-rw-r--r--  1 root root 10240 Aug 26 15:06 0f-04-01
-rw-r--r--  1 root root  2048 Aug 26 15:06 0f-04-03
-rw-r--r--  1 root root  3072 Aug 26 15:06 0f-04-04
-rw-r--r--  1 root root  3072 Aug 26 15:06 0f-04-07
-rw-r--r--  1 root root  9216 Aug 26 15:06 0f-04-08
-rw-r--r--  1 root root  2048 Aug 26 15:06 0f-04-09
-rw-r--r--  1 root root  4096 Aug 26 15:06 0f-04-0a
-rw-r--r--  1 root root  3072 Aug 26 15:06 0f-06-02
-rw-r--r--  1 root root  6144 Aug 26 15:06 0f-06-04
-rw-r--r--  1 root root  2048 Aug 26 15:06 0f-06-05
-rw-r--r--  1 root root  2048 Aug 26 15:06 0f-06-08

(By the way, the file 06-3c-03 is the microcode file for my particular CPU: Family 06h, Model 03Ch, Stepping 03h, as determined from the CPU World Web site.)

Then I copied to the boot directory the cpio file created when I merged the packages:

# cp /lib/firmware/microcode.cpio /boot/

Then I added an initrd line to /boot/grub/grub.cfg as shown below:

# grep -B 15 -A 1 initrd /boot/grub/grub.cfg

### BEGIN /etc/grub.d/10_linux ###
menuentry 'Gentoo GNU/Linux' --class gentoo --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-525a90f1-8ad2-44a3-ade3-20f18a0a9595' {
        load_video
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos1'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  f6ffc085-66fe-4bbe-b080-cec355749f85
        else
          search --no-floppy --fs-uuid --set=root f6ffc085-66fe-4bbe-b080-cec355749f85
        fi
        echo    'Loading Linux 3.18.11-gentoo ...'
        linux   /vmlinuz-3.18.11-gentoo root=/dev/sda5 ro  drm_kms_helper.edid_firmware=edid/1920x1080_Clevo_W230SS.bin i915.modeset=1 rcutree.rcu_idle_gp_delay=1
        initrd /microcode.cpio
}

After rebooting:

# grep microcode /proc/cpuinfo
microcode       : 0x1c
microcode       : 0x1c
microcode       : 0x1c
microcode       : 0x1c
microcode       : 0x1c
microcode       : 0x1c
microcode       : 0x1c
microcode       : 0x1c
# dmesg | grep microcode
[    0.000000] CPU0 microcode updated early to revision 0x1c, date = 2014-07-03
[    0.049968] CPU1 microcode updated early to revision 0x1c, date = 2014-07-03
[    0.065070] CPU2 microcode updated early to revision 0x1c, date = 2014-07-03
[    0.080101] CPU3 microcode updated early to revision 0x1c, date = 2014-07-03
[    0.268736] microcode: CPU0 sig=0x306c3, pf=0x10, revision=0x1c
[    0.268838] microcode: CPU1 sig=0x306c3, pf=0x10, revision=0x1c
[    0.268935] microcode: CPU2 sig=0x306c3, pf=0x10, revision=0x1c
[    0.269034] microcode: CPU3 sig=0x306c3, pf=0x10, revision=0x1c
[    0.269131] microcode: CPU4 sig=0x306c3, pf=0x10, revision=0x1c
[    0.269230] microcode: CPU5 sig=0x306c3, pf=0x10, revision=0x1c
[    0.269329] microcode: CPU6 sig=0x306c3, pf=0x10, revision=0x1c
[    0.269448] microcode: CPU7 sig=0x306c3, pf=0x10, revision=0x1c
[    0.269570] microcode: Microcode Update Driver: v2.00 , Peter Oruba

As you can see above, the microcode early update kernel driver updates the microcode version to 0x1c at boot (cf. 0x12 originally). If you have a different model of CPU to mine, of course the version in your case could be different.

Note that the line ‘initrd /lib/firmware/microcode.cpio‘ in the file grub.cfg does not work for me. It has to be ‘initrd /microcode.cpio‘ and the file microcode.cpio has to be in the /boot directory:

# ls /boot
System.map-3.18.11-gentoo  config-3.18.11-gentoo  grub  lost+found  microcode.cpio  vmlinuz-3.18.11-gentoo

Note also that the precise steps specified in Comment #41 of Gentoo Bug Report No. 528712 do not work for me and others (see Gentoo Forums thread microcode-data-20150121-r1 with USE=initramfs: kernel panic). If I build the kernel with CONFIG_INITRAMFS_SOURCE="/lib/firmware/microcode.cpio", delete the line ‘initrd /microcode‘ from grub.cfg, delete the file /boot/microcode.cpio and reboot, the kernel panics and the last two console lines are as follows:

[    3.142079] drm_kms_helper: panic occurred, switching back to text console
[    3.142879] ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(8,5)

Unless Gentoo developer SpanKY explains how he managed to get the procedure he gave in Comment #41 of Gentoo Bug Report No. 528712 to work, it seems the normal behaviour when applying the steps he gave would be for the kernel to panic. Even Gentoo developer Daniel Pielmeier experienced a kernel panic when he applied SpanKY‘s steps (Comment #54 of Gentoo Bug Report No. 528712).

As the procedure I gave above works fine, I therefore reverted to using CONFIG_INITRAMFS_SOURCE="", copying /lib/firmware/microcode.cpio to /boot/microcode.cpio again and re-adding the line ‘initrd /microcode.cpio‘ in the file grub.cfg. However, if you did not have an initramfs and were able to get the precise procedure given in Comment #41 of Gentoo Bug Report #528712 to work, please post a comment here.