grub2: undefined function 'terminal_output' observed in petitboot logs

[pridhiviraj]

grub2: undefined function 'terminal_output'
boot option sdb2#Ubuntu is resolved, sending to clients
boot option sdb2#Ubuntu, with Linux 4.15.17+ is resolved, sending to clients
boot option sdb2#Ubuntu, with Linux 4.15.17+ (recovery mode) is resolved, sending to clients
boot option sdb2#Ubuntu, with Linux 4.15.0-22-generic is resolved, sending to clients
boot option sdb2#Ubuntu, with Linux 4.15.0-22-generic (recovery mode) is resolved, sending to clients
boot option sdb2#Ubuntu, with Linux 4.15.0-20-generic is resolved, sending to clients
boot option sdb2#Ubuntu, with Linux 4.15.0-20-generic (recovery mode) is resolved, sending to clients
Running command:
 exe:  /usr/sbin/pb-plugin
 argv: '/usr/sbin/pb-plugin' 'scan' '/var/petitboot/mnt/dev/sdb2'
Scanning device /var/petitboot/mnt/dev/sdb2
No plugins found
SKIP: dm-0: no ID_FS_TYPE property
SKIP: dm-1: no ID_FS_TYPE property
SKIP: sda1: no ID_FS_TYPE property
SKIP: dm-2: no ID_FS_TYPE property
SKIP: sdb1: no ID_FS_TYPE property
Running command:
 exe:  /usr/sbin/vgscan
 argv: '/usr/sbin/vgscan' '-qq'
Running command:
 exe:  /usr/sbin/vgchange
 argv: '/usr/sbin/vgchange' '-ay' '-qq'
Snapshot successfully created for sda2
mounting device /dev/sda2 read-only
trying parsers for sda2
grub2: undefined function 'terminal_output'



Firmware version:
 Product Name          : OpenPOWER Firmware
 Product Version       : open-power-SUPERMICRO-P9DSU-V1.16-20180518-imp
 Product Extra         : 	op-build-1c5f0cc
 Product Extra         : 	skiboot-v6.0-p33aa9e0
 Product Extra         : 	hostboot-f911e5c-p36956fa
 Product Extra         : 	occ-77bb5e6
 Product Extra         : 	linux-4.16.7-openpower2-p3436ea7
 Product Extra         : 	petitboot-v1.7.1-pee4c1f8
 Product Extra         : 	machine-xml-218a77a
 Product Extra         : 	sbe-8e0

[sammj]

This is just because we don't support the terminal_output function in our GRUB parser; it just gets skipped with the message above. That said we could support it, but we would need to decide what to do with the possible values we may receive. For example on an Ubuntu install I have here we get terminal_output gfxterm. Other potential options include console, serial, vga_text, and so on. Is it worth trying to map these to hvc0, hvc1, and tty0 that we most often have on POWER, or just ignore them and leave it to the setting in Petitboot's config?