Comment 5 for bug 1558747

Petitboot logs: https://pastebin.canonical.com/152293/

Running command:
 exe: /usr/bin/tftp
 argv: '/usr/bin/tftp' '-g' '-l' '/tmp/pb-XsMOPF' '-r' '/ppc64el/pxelinux.cfg/01-98-be-94-01-0f-4c' '10.244.192.10' '69'
boot option enp1s0f0#netboot enp1s0f0 (pxelinux.0) is resolved, sending to clients
Sending renew...
Lease of 10.244.192.175 obtained, lease time 43200
deleting routers
adding dns 10.244.192.10
Sending renew...
Lease of 10.244.192.175 obtained, lease time 43200
deleting routers
adding dns 10.244.192.10
Sending renew...
Lease of 10.244.192.175 obtained, lease time 43200
deleting routers
adding dns 10.244.192.10
Running command:
 exe: /usr/bin/tftp
 argv: '/usr/bin/tftp' '-g' '-l' '/tmp/pb-ebec6t' '-r' '/pxelinux.0' '10.244.192.10' '69'
running boot hook 01-create-default-dtb
Running command:
 exe: /etc/petitboot/boot.d/01-create-default-dtb
 argv: '/etc/petitboot/boot.d/01-create-default-dtb'
Warning (reg_format): "reg" property in /ibm,opal/flash@0 has invalid length (8 bytes) (#address-cells == 0, #size-cells == 0)
boot hook 01-create-default-dtb specified boot_dtb=/tmp/tmp.TUFj3U
running boot hook 20-set-stdout
Running command:
 exe: /etc/petitboot/boot.d/20-set-stdout
 argv: '/etc/petitboot/boot.d/20-set-stdout'
running boot hook 90-sort-dtb
Running command:
 exe: /etc/petitboot/boot.d/90-sort-dtb
 argv: '/etc/petitboot/boot.d/90-sort-dtb'
Warning (reg_format): "reg" property in /ibm,opal/flash@0 has invalid length (8 bytes) (#address-cells == 0, #size-cells == 0)
Running command:
 exe: /usr/sbin/kexec
 argv: '/usr/sbin/kexec' '-l' '--dtb=/tmp/tmp.TUFj3U' '/tmp/pb-ebec6t'
load_kernel: /tmp/pb-ebec6t is not a valid ELF file
kexec_load: failed: (256)