Gentoo grub-probe not working

 I have a bunch of history commands I run when I d a new kernel etc and one stopped working.

grub-mkconfig would fail with grub-probe for /.

 

I read about a simialr issue where you where supposed to have a link for /dev/root to your root device and that fixed it right up. 

grub-probe fails and I don't have /dev/root set

 

StudyPC /usr/src/linux # grub-probe /
grub-probe: error: cannot find a device for / (is /dev mounted?).
StudyPC /usr/src/linux # ls -l /dev/root
ls: cannot access '/dev/root': No such file or directory

 

Mount shows / is there and on sda2

StudyPC /usr/src/linux # mount
/dev/sda2 on / type btrfs (rw,noatime,ssd,discard,noacl,space_cache,subvolid=5,subvol=/)
..

waffle

..

 

So symlink that and try grub-mkconfig again

 

StudyPC /usr/src/linux # ln -s /dev/sda2 /dev/root
StudyPC /usr/src/linux # ls -l /dev/root
lrwxrwxrwx 1 root root 9 Mar 19 13:04 /dev/root -> /dev/sda2
StudyPC /usr/src/linux # grub-probe
No path or device is specified.
Usage: grub-probe [OPTION...] [OPTION]... [PATH|DEVICE]
Try 'grub-probe --help' or 'grub-probe --usage' for more information.
StudyPC /usr/src/linux # grub-probe /
btrfs

And we're good!  No more handcoding grub.cfg

Time for a change

 We're moving on a bit in life.  Got an empty house, got a stupid car.

So it's time to start tracking the stuff we watch and how good it was.

So let start with 

God Bless America

Classic movie.  This man gets all the things I hate. Social media is this generation's smoking.  It will get worse when we look back on it.

Solid 9/10

Blake's 7 the complete series.

This aged better than I thought it would. Loved this series as a child.  I tried to make the liberator so many times for art projects.

Decent 7/10

Cold Case

Really enjoyed this as my going to bed series.  So I may have missed a bit here and there.  A little samey but good arcs in the series and soem interesting back stories.

Decent 7/10

Nanomesher Weather Board tweak

 I've backed a number of Nanomesher's boards onn Kickstarter from the weather prodboard to different audio boards, and they've all been great.  The DAC2 in particular is a fantastic piece of kit.

I was playign with the Weather board and tweaked the script a bit to show the time and date rather than the default Nanomesher PiAirMon.

To do this vi the PiAirMon.py file and comment out the line with the old text and add the new lines:

 

        with canvas(device) as draw:
#            draw.text((1, 1), "Nanomesher Air Mon", font=font1, fill="white")
             now = datetime.datetime.now()
            draw.text((1, 1), now.strftime('%H:%M:%S %a %d %b'), font=font1, fill="white")

This shows in your locale the time, day, date and month.

So mine currently shows

14:37:29 Fri 02 Apr

 

This sits on the desk in front of me to remind me to open the window when the CO2 gets too high, and it's nice having a clock on it.

 

 

CS:GO on Linux not starting

Valve, for a company that supposedly loves Linux your support is terrible. I got pointed to a community forum for support when logging this with them. To top it off I paid for it a week before they made it free. Grr..

So I could get CS:GO to launch sometimes so it did work but rarely.

After some pretty extreme testing it seems you need to slow it down when launching.

I found sometime just alt tabbing repeatedly was enough but that was hard to replicate.

Ready for the most stupid work around ever?

Are you sitting down for this one?

I run Gentoo Linux so everything is compiled from scratch. You can see where this is going..

I start compiling something.  Mesa is my usual goto.  Once this is compiling it slows down the launch of CSGO enough that it works.

This is just insane. I tried changing versions of libraries, dependencies etc but none of this mattered just making the system loaded while launching works.


Edit:  turns out you can avoid all this by adding the -nojoy option in the command line options.

Postfix with ECDSA certificate not connecting

I was playing with this a while back and it didn't work and got forgotten about but this time I dug into it further.

There are lots of guides for setting this up such as

https://zhadum.org.uk/2015/07/25/ssl-certificate-agility-with-postfix/

but this did not work for me.  Using

openssl s_client -cipher ECDHE-ECDSA-AES128-SHA -connect localhost:25 -starttls smtp

CONNECTED(00000003)
1995830688:error:14094410:SSL routines:ssl3_read_bytes:sslv3 alert handshake failure:../ssl/record/rec_layer_s3.c:1399:SSL alert number 40
---
no peer certificate available
---
No client certificate CA names sent

failed and said it had no presented no cert.

After looking at my cert file I noticed:

 openssl x509 -text -noout
-----BEGIN CERTIFICATE-----
MIID9zCCA5ygAwIBAgIQJDK88IzKKF3Cva9HhMswejAKBggqhkjOPQQDAjCBkDEL
MAkGA1UEBhMCR0IxGzAZBgNVBAgTEkdyZWF0ZXIgTWFuY2hlc3RlcjEQMA4GA1UE
BxMHU2FsZm9yZDEaMBgGA1UEChMRQ09NT0RPIENBIExpbWl0ZWQxNjA0BgNVBAMT

...

        Subject Public Key Info:
            Public Key Algorithm: id-ecPublicKey
                Public-Key: (384 bit)
                pub: 
                    04:24:64:3c:45:da:96:fe:eb:cd:0b:4c:9b:da:4f:
                    db:dd:0d:fa:e9:14:54:67:96:3e:81:3f:55:b8:1d:
                    36:0a:db:c7:a8:be:32:a2:5d:59:4c:dd:c6:11:78:
                    a4:cd:6b:12:c4:0d:76:af:6e:ef:8e:b5:78:4a:ae:
                    94:5a:90:ac:21:04:6a:f1:f2:6e:2e:8d:87:d8:46:
                    a3:54:f3:7e:f0:08:8e:81:3b:1c:0a:1d:ff:b8:a7:
                    fd:db:91:3a:b6:0b:48
                ASN1 OID: secp384r1
                NIST CURVE: P-384

from the postfix page

    smtpd_tls_eecdh_grade = strong | ultra

    # Underlying curves, best not changed:

    # tls_eecdh_strong_curve = prime256v1

    # tls_eecdh_ultra_curve = secp384r1

In my version 3.1 it defaults to strong

postconf -d | grep smtpd_tls_eecdh_grade

smtpd_tls_eecdh_grade = strong

but needs to be set to ultra to support sec384r1 which the cert was issued with. So adding the line

smtpd_tls_eecdh_grade = ultra

to main.cf made the cert work.

None of the other articles I have seen mention this so maybe it's not that common.

Switch your Raspberry Pi 3 to use a hard drive

I have a Pi 3 that is a DNS, web, email etc server and it's gone through a few SD cards and gets bogged down in high wait % in top sometimes.  It has a USB drive for storage for Storj etc and I was reading how you can boot a Pi 3 with a hard drive to speed things up and hopefully be a bit more reliable than the SD cards have been.

So I found this article

https://thepi.io/how-to-boot-your-raspberry-pi-from-a-usb-mass-storage-device/

Now a bunch of gotchas came up.

Firstly the boot USB option is a OTP setting.  This means once it's set, it for good on your device. Read up on this before doing it!

https://github.com/raspberrypi/documentation/blob/master/hardware/raspberrypi/bootmodes/bootflow.md

 I had a spare drive so I restored a Jessie image to the drive and plugged it in after  setting the option

program_usb_boot_mode=1

and it seem to boot (it's headless) but the drive was accessing, the network was flashing etc. Seems pretty easy.

Ok lets try and migrate the current SD card and drive to a new drive.

So some points to note here.  I tried the SDCard again to get DNS etc back up while I moved data around and it would not boot. Seems you need to remove the line we added earlier

program_usb_boot_mode=1

from /boot/config.txt or the SD card won't boot again. That's a bit annoying.

So I imaged the SDCard and restored this to the drive and tried to boot this and it started but then did not complete booting. OK silly move, need to modify the /etc/fstab on the root partition and the /boot/cmdline to say sda rather than the mmc device that is the SDCard.

Once that was done it booted OK.  We're getting there. Tried to use raspi-config to exapnd the root partition but that doesn't know what the drive is and only works on SDCards.  Doh. Back to the PC and expand with GParted and finish copying the data over and we're in business.

So in short to move you RaPi3 to a harddrive:

Image your SDCard and restore this to the new harddrive. 
Expand the harddrive root partiion with GParted or similar.
Modify the /etc/fstab and /boot/cmdline on the new drive to use sda rather than the mmc device ( I had 3 entries)
On the PI, set the "program_usb_boot_mode=1" option in /boot/config.txt and reboot.
Shut the Pi down and remove the SDCard and plug in the USB drive and it should boot.

Hope that saves some frustration :-)

A simple video card upgrade... not so much

I wanted to get a new video card and found a deal on a Sapphire RX580 and thought great, going from a RX390 to a RX580 should be easy. Both are AMD, both are just rehashes of an older card so drivers are established.

But no, seems the Sapphire card is cheap for a reason...

So started up in Linux and it booted to the point where it said switching to amdgpufb, then blank screen.  HDMI was UP (the card has two HDMI ports and one goes to an AV system for sound).  It's all working but you can't see anything. crtrl-alt-delete and try again.

Change kernel line options in grub to include nomodeset and it boots and you can see (apart from about 2 minutes of tearing when it tries to start gdm)

Logs look fine looks amdgpu is starting OK and recognising it as an RX480 which it is based on. Doh, wrong firmware.  OK so update from TONGA to POLARIS10 firmware blobs int he kernel. My kernel doesn't use ramdisk it just boots and includes all the firmware for video, wifi etc.  Not the linux way but it works and it's quick.

Boot again, but still blank screen and now firmware loads and the card looks to be running. Hmmm...

Boot into windows and just make sure and the card is fine.

Run make menuconfig on the kernel and check for options but everything is just amdgpu generic not specific to a model.  Found a firmware option related to EDID and checked the docs on this in /usr/src/linux/Documenation/EDID/Howto.txt.  This talks about video starting but cards not reading EDID from the monitor correctly and stopping at a blank screen when start KMS.  OK sounds promising...

Making a EDID file is as simple as running make in that directory to use the default ones.

Copy 1920x1080.bin to /lib/firmware and add that to the kernel blobs and reboot. Still no good.

Google comes to the rescue to find an Arch Linux article (damn these guys document well) which is similar to Gentoo and it mentions you need to turn on this firmware at boot with a kernel option

drm_kms_helper.edid_firmware=1920x108.bin

and sure enough it boots and video stays on.

So if you have a Sapphire RX580 (pulse in my case) and linux and have blank video issues try this. I'm sorry to sapphire if it's a general RX580 thing but I didn't find any other posts etc on this issue so I'm guessing not.

I can post line by line if anyone comes across this and it doesn't make sense to them.