#!/bin/sh

set -e

# input is a tarball on stdin with kernel, dtbs and cmdline in /boot
# output is an tar to be extracted onto a SD card

mkdir -p /files 
cd /files

# extract. BSD tar auto recognises compression
[ -t 0 ] || bsdtar xzf -

cd /

# copy/convert files 
mkdir -p /boot/dtb/broadcom
cp /files/boot/dtb/broadcom/bcm2837-rpi-3-b*.dtb /boot/dtb/broadcom
/bin/mkimage -A arm64 -O linux -T kernel -C gzip -a 0x80000 -e 0x80000 \
             -d /files/boot/kernel /boot/kernel.uimg >> /boot/uboot.log
/bin/mkimage -A arm64 -O linux -T script -C none -a 0x00000000 -e 0x00000000 -n RPi3 \
             -d /boot/boot.script /boot/boot.scr  >> /boot/uboot.log

# build an initrd and convert it
rm -rf /files/boot
cd /files && find . | cpio -o -H newc | gzip > /initrd.img
/bin/mkimage -A arm64 -O linux -T ramdisk -d /initrd.img /boot/initrd.uimg  >> /boot/uboot.log

# now everything is setup in /boot just need to tar it
cd /boot && tar cf - .