#!ipxe


# I've assume IPv4 for this script, so if we need IPv6, it may need
#   modifications.


# Require only verified images to boot
imgtrust --permanent


# For the "focal" part of the URL string, in case that changes in the future.
set ubuntu-variant focal

goto get_arch


#################
### This section is at the top, so it's easier to modify.
:static_ip_boot_setup

# Open all network interface devices, so we aren't restricted to just the first
ifopen
sleep 1

# Currently we just configure IP info by MAC address. So we iterate over
#   MAC addresses and set the variables. To ensure we use the desired
#   device, we iterate over all devices and simply find matches by
#   MAC address.
set idx:int32 0
set successful f
:loop
isset ${net${idx}/mac} || goto loop_done

######################## SET STATIC IP INFO HERE #############################
# Just copy/paste an entire line to add more

iseq ${net${idx}/mac:string} "00:01:02:A0:B1:C1" && set ip-dev-name eth0 && set ip-addr "192.168.1.5" && set ip-gateway "192.168.1.1" && set ip-netmask "255.255.255.0" && set ip-dns "1.1.1.1" && set successful t && goto loop_done ||
iseq ${net${idx}/mac:string} "03:04:05:D4:E5:F6" && set ip-dev-name eth0 && set ip-addr "192.168.99.2" && set ip-gateway "192.168.99.1" && set ip-netmask "255.255.255.0" && set ip-dns "1.1.1.1" && set successful t && goto loop_done ||
##############################################################################
inc idx && goto loop

:loop_done
# If we have not successfully found a MAC match, then we error, because we
#   also failed DHCP. So there's nothing we can do but fail.
iseq successful f && goto error_handler

# If on the other hand we're successful, then we construct the kernel ip= line
set ip-info ${ip-addr}::${ip-gateway}:${ip-netmask}::${ip-dev-name}:off:${ip-dns}

# And setup IPXE networking.

# First, set device info
set net${idx}/ip ${ip-addr}
set net${idx}/gateway ${ip-gateway}
set net${idx}/netmask ${ip-netmask}
set net${idx}/dns ${ip-dns}

# Now we close all net devices and enable only the one we need.
# Sleep a little between, so we don't error by continuing too fast before the
#   device is actually ready
sleep 1
ifclose
sleep 1
ifopen net${idx}
sleep 1

# Set settings again in case the ifdown/ifup cleared them
set net${idx}/ip ${ip-addr}
set net${idx}/gateway ${ip-gateway}
set net${idx}/netmask ${ip-netmask}
set net${idx}/dns ${ip-dns}
sleep 1

# Now we have the ip= line and the IPXE network configured, so we can
#   download and boot.
goto boot_all
###
#################


# In case we want to... log?? Or do something else.
:error_handler
echo "###########################################################"
echo "An unspecified error has occurred."
echo "The system will sleep for two minutes and then reboot."
echo "###########################################################"
sleep 60
sleep 60
reboot
# Should not occur, but just in case...
sleep 5
exit



# Get relevant CPU arch.
:get_arch
iseq ${buildarch} arm32 && goto start_arm32 ||
iseq ${buildarch} arm64 && goto start_arm64 ||
iseq ${buildarch} i386 && goto start_i386 ||
iseq ${buildarch} x86_64 && goto start_amd64 ||
goto error_handler


# Builds may be done on 32-bit, but machines will always be 64-bit.
# Keep this section just in case we want to use 32-bit machines in the future.
:start_arm32
goto start_arm64

:start_i386
goto start_amd64


# Set arch info and determine if we can use DHCP for network.
# Then either boot or goto static IP setup.
:start_arm64
set arch-info arm64
dhcp || goto static_ip_boot_arm64
sleep 1
set ip-info dhcp
goto boot_all

:start_amd64
set arch-info amd64
dhcp || goto static_ip_boot_amd64
sleep 1
set ip-info dhcp
goto boot_all


# This process should be the same for arm and x86, but I'll leave this section
#   intact in case it turns out it's not the same
:static_ip_boot_arm64
goto static_ip_boot_setup

:static_ip_boot_amd64
goto static_ip_boot_setup



:boot_all

# We use HTTP because IPXE's HTTPS implementation is lacking. So we delegate
#   integrity and validation to imgverify.


# Naming the squashfs download "/squashfs" is required, otherwise the boot
#   kernel fails to load it in the "root=" part of the kernel cmdline.
# However, note that imgverify will fail if you refer to it as "/squashfs"
#   instead of "squashfs".

imgfetch http://images.sysdeploy.org/${ubuntu-variant}/${arch-info}/squashfs /squashfs || goto error_handler
imgverify --signer images.sysdeploy.org squashfs http://images.sysdeploy.org/${ubuntu-variant}/${arch-info}/squashfs.sig || goto error_handler

# "--signer" validates against the subject common name field of the signing
#   certificate. That signing cert must have both the digital signature key
#   usage set and the code-signing key usage extension set.

# By default, IPXE trusts the default Mozilla global root CA list, so
#   make sure you pick a common name with a FQDN you control, even if you're
#   using a custom CA that you import during build.


initrd http://images.sysdeploy.org/${ubuntu-variant}/${arch-info}/boot-initrd || goto error_handler
imgverify --signer images.sysdeploy.org boot-initrd http://images.sysdeploy.org/${ubuntu-variant}/${arch-info}/boot-initrd.sig || goto error_handler

kernel http://images.sysdeploy.org/${ubuntu-variant}/${arch-info}/boot-kernel || goto error_handler
imgverify --signer images.sysdeploy.org boot-kernel http://images.sysdeploy.org/${ubuntu-variant}/${arch-info}/boot-kernel.sig || goto error_handler


# Get accurate time so we can set the clock in kernel boot cmdline
ntp pool.ntp.org || goto error_handler


boot boot-kernel initrd=boot-initrd rootfstype=squashfs root=/squashfs ip=${ip-info} overlayroot=tmpfs:recurse=0 systemd.clock-usec=${unixtime:int32}000000 ds=nocloud-net;s=https://cloud-init.sysdeploy.org/ || goto error_handler

# unixtime variable must be used with int32, because that's the only way it
#   will display as decimal digits. unit32 and string both display as hex.
#   Therefore this will stop working in 2038.