From: John Henderson <jh982@hotmail.com>
To: "alpine-devel@lists.alpinelinux.org" <alpine-devel@lists.alpinelinux.org>
Subject: [alpine-devel] Unable to access serial console during initial installation
Thread-Topic: Unable to access serial console during initial installation
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Date: Fri, 14 Oct 2016 03:26:30 +0000
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[Please note that I posted this at the beginning of the week on alpine-user=
 (no responses as of now), but it seems like this report might better be cl=
assified as a dev issue, so I'm re-posting here.  Thanks!]

Hi,=20

I'm trying to install Alpine Linux 3.4.4 (via extended 64-bit ISO) on a Net=
gate RCC-VE 2440 system (specialized Intel Rangeley-based SOHO router-type =
hardware; if interested, see: http://store.netgate.com/ADI/RCC-VE-2440.aspx=
 ).=20

I'm unable to proceed since I can't get the installation to come up on the =
serial console. This particular hardware has no video access, and no expans=
ion capabilities to (even temporarily) enable it. I can't even swap HDDs/SS=
Ds or the like (if I wanted to go down that road), since I'm actually insta=
lling Alpine to the eMMC flash soldered on-board the Netgate...=20

For context, I followed the instructions at:=20

  http://wiki.alpinelinux.org/wiki/Enable_Serial_Console_on_Boot=20

Namely, I modified the syslinux configuration file ('/boot/syslinux/syslinu=
x.cfg') on the default install media, as follows:=20

  *** syslinux.cfg.orig	2016-09-28 11:43:51.000000000 -0500=20
  --- syslinux.cfg	2016-10-08 15:44:03.581309751 -0500=20
  ***************=20
  *** 1,7 ****=20
    =20
    timeout 20=20
    prompt 1=20
    default grsec=20
    label grsec=20
            kernel /boot/vmlinuz-grsec=20
  ! append initrd=3D/boot/initramfs-grsec modloop=3D/boot/modloop-grsec mod=
ules=3Dloop,squashfs,sd-mod,usb-storage quiet=20
  --- 1,8 ----=20
    =20
  + serial 0 115200=20
    timeout 20=20
    prompt 1=20
    default grsec=20
    label grsec=20
            kernel /boot/vmlinuz-grsec=20
  ! append initrd=3D/boot/initramfs-grsec modloop=3D/boot/modloop-grsec mod=
ules=3Dloop,squashfs,sd-mod,usb-storage console=3DttyS0,115200=20

With this modification, I'm able to boot the install DVD over serial consol=
e, get past the BIOS, choose my boot device, and view two kernel messages a=
fter Alpine Linux starts to boot --- right up to the point where the initra=
mfs takes over. After that, I can't get anything on the console, try as I m=
ight (I don't get gibberish, which might reflect mismatched tty parameters =
--- I just don't get anything at all). Now, my understanding is that the in=
itramfs is supposed to "inherit" the proper kernel boot command-line parame=
ters (and therefore continue with a properly configured serial console). Ho=
wever, that doesn't seem to be happening in this case.=20

Looking around the Alpine Linux code, I thought I might have found a releva=
nt bug in the '/init' script within the initramfs on the install media, as =
the optional getty invocation (tied to serial console access) actually reve=
rses the order of its arguments. Here's my patch for that (note the exchang=
e of the '$speed' and '$tty' environmental variables):=20

  *** init.orig	2016-10-08 17:25:30.853250350 -0500=20
  --- init	2016-10-10 10:02:58.629366556 -0500=20
  ***************=20
  *** 130,136 ****=20
                    if ! grep -q "^$tty:" $sysroot/etc/inittab; then=20
                            echo "# enable login on alternative console" \=
=20
>> $sysroot/etc/inittab=20
  ! echo "$tty::respawn:/sbin/getty $line $speed $tty $term" \=20
>> $sysroot/etc/inittab=20
                    fi=20
                    if [ -e "$sysroot"/etc/securetty ] && ! grep -q -w "$tt=
y" "$sysroot"/etc/securetty; then=20
  --- 130,136 ----=20
                    if ! grep -q "^$tty:" $sysroot/etc/inittab; then=20
                            echo "# enable login on alternative console" \=
=20
>> $sysroot/etc/inittab=20
  ! echo "$tty::respawn:/sbin/getty $line $tty $speed $term" \=20
>> $sysroot/etc/inittab=20
                    fi=20
                    if [ -e "$sysroot"/etc/securetty ] && ! grep -q -w "$tt=
y" "$sysroot"/etc/securetty; then=20


Unfortunately, even after fixing this (presumptive?) bug, I still can't get=
 any serial communication after initramfs on boot.=20

Any ideas, please?=20

Thanks,=20
John =


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