ubuntu-cpc: disable kernel and initramfs symlinks in /boot

This is required by the new UEFI binary hook as we mount the ESP on
/boot and the ESP filesystem doesn't support symlinks.
We keep symlinks for s390x images which do not use UEFI anyway.

live-build/ubuntu-cpc/hooks.d/chroot/999-cpc-fixes.chroot

@@ -124,6 +124,21 @@ fi
 
 #### END COMMON ARCH FUNCTIONS
 
+# For everything except s390x, disable kernel and initramfs symlinks
+case $arch in
+   # On s390x the sipl.conf is static right now with just two boot options.
+   s390x)
+      exit 0
+      ;;
+esac
+
+find "${rootd}/boot" -type l -exec rm {} \;
+kernel_img_conf="${rootd}/etc/kernel-img.conf"
+if grep -q '^do_symlinks = ' "$kernel_img_conf" 2> /dev/null; then
+    sed -i 's/^do_symlinks = .*$/do_symlinks = no/g' "$kernel_img_conf"
+else
+    echo "do_symlinks = no" >> "$kernel_img_conf"
+fi
 
 case $arch in
 	# ARM, ppc, riscv64 and s390x images are special