test.bash

#!/usr/bin/bash

function update_xen_image()
{
	local config="xen.conf"
	local kernel="/boot/vmlinuz-linux-zen-hardened"
	local ramdisk="initramfs-linux-zen-hardened.img"
	local ucode="xen-efi-intel-ucode.bin"

	# Get the end address of the padding section as hexadecimal in UPPERCASE for bc
	local base="$(objdump -h xen.efi | perl -ane '/\.pad/ && printf "%016x\n", hex($F[2]) + hex($F[3])' | tr "a-z" "A-Z")"
	# Section offset for the added files, padded to power of 2 boundaries
	local offset=0

	# Round up to next power of 2
	local snippet='my $v = hex($ARGV[0]); $v -= 1; $v |= $v >> 1; $v |= $v >> 2; $v |= $v >> 4; $v |= $v >> 8; $v |= $v >> 16; $v += 1; print sprintf("%X", $v);'

	local cmdline=();

	for name in config ucode kernel ramdisk;
	do
		if [ -z "${!name}" ];
		then
			continue
		fi

		# Calculate the address of the section
		local vma=$(echo "obase=16;ibase=16;$base + $offset" | bc)
		# Create the variable holding the commandline snippet
		cmdline+=("--add-section .$name=\"${!name}\" --change-section-vma .$name=0x$vma")
		# Convert file size to hex
		local size=$(echo "obase=16;$(wc -c ${!name} | cut -d ' ' -f 1)" | bc)
		# Add the file size to the offset
		offset=$(echo "obase=16;ibase=16;$offset + $size" | bc)
		# Pad the offset to the next power of 2
		offset=$(perl -e "$snippet" "0x$offset")
	done

	local run_str="objcopy ${cmdline[@]} \"xen.efi\" \"xen-signed.efi\""
	bash -c "$run_str"
}

update_xen_image