Re: [PATCH 1/1] services: Add agetty service.

[myglc2 <myglc2@gmail.com>]

On 02/14/2017 at 19:24 Leo Famulari writes:

> On Tue, Feb 14, 2017 at 07:12:44PM -0500, Leo Famulari wrote:
>> * gnu/services/base.scm (<agetty-configuration>): New record type.
>> (agetty-shepherd-service, agetty-service): New procedures.
>> (agetty-service-type): New variable.
>
> My intention is to get a serial tty, for example /dev/ttyS0, so that I
> can install GuixSD on a device that lacks any graphical display
> interfaces:
[...
> However, it doesn't work when I boot my physical device with the same
> installer image.
>
> When I connect to my physical device using the Keyspan USA-19H
> serial-to-USB converter, I can watch the system boot, but Shepherd never
> reports that the 'term-ttyS0' service has started, and I never see the
> MOTD or login prompt.
>
> Any advice or debugging ideas?

Hi Leo,

I'm very happy to see you doing this. I got agetty working on IPMI
serial over LAN (SOL) on a ASRock MT-C224 motherboard as follows:

I made these changes in GRUB.scm ...

diff --git a/gnu/system/grub.scm b/gnu/system/grub.scm
index b18b8be6d..e68cec7f4 100644
--- a/gnu/system/grub.scm
+++ b/gnu/system/grub.scm
@@ -197,7 +197,8 @@ system string---e.g., \"x86_64-linux\"."
     insmod efi_uga
   fi
 
-  terminal_output gfxterm
+  serial --unit=0 --speed=115200
+  terminal_input serial console; terminal_output console
 "
         ""))
 
I found the serial port like so ...

dmesg | grep tty
[    0.000000] Command line: BOOT_IMAGE=/gnu/store/ksigckplbh1669iy62pqa17j7sid9vmw-linux-libre-4.9.9/bzImage --root=/dev/md3 --system=/gnu/store/ssh2kjijcg7fvfaafmn4jj0chkmzaxzr-system --load=/gnu/store/ssh2kjijcg7fvfaafmn4jj0chkmzaxzr-system/boot console=ttyS1,115200
[    0.000000] Kernel command line: BOOT_IMAGE=/gnu/store/ksigckplbh1669iy62pqa17j7sid9vmw-linux-libre-4.9.9/bzImage --root=/dev/md3 --system=/gnu/store/ssh2kjijcg7fvfaafmn4jj0chkmzaxzr-system --load=/gnu/store/ssh2kjijcg7fvfaafmn4jj0chkmzaxzr-system/boot console=ttyS1,115200
[    0.000000] console [ttyS1] enabled
[    3.622999] 00:07: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200)
is a 16550A

... I installed the shadow package and I did this ...

agetty ttyS1 -l /root/.guix-profile/bin/login &

And I can log in, run screen and run emacs.

FWIW, there is no mention in sheperd.log of the serial port.

HTH, George