#!/bin/bash
#
#     Create a docker image raspbian distribution image for raspberry-pi
#
# Change the SRC path if needed:
SRC=https://downloads.raspberrypi.org/raspbian_lite_latest

set -e
sudo echo Info: Need root access to mount the image to extract the content
mkdir raspbian-tmp
cd raspbian-tmp
echo Download image...
wget --trust-server-names $SRC
unzip *.zip && rm *.zip
DISK_IMG=$(ls *.img | sed 's/.img$//')
OFFSET=$(fdisk -lu $DISK_IMG.img | sed -n "s/\(^[^ ]*img2\)\s*\([0-9]*\)\s*\([0-9]*\)\s*\([0-9]*\).*/\2/p")
mkdir root
sudo  mount -o loop,offset=$(($OFFSET*512)) $DISK_IMG.img root
# Disable preloaded shared library to get everything including networking to work on x86
sudo mv root/etc/ld.so.preload root/etc/ld.so.preload.bak

# Copy qemu-arm-static in the image be able to interpret arm elf on x86
if /usr/bin/qemu-arm-static -version | grep 2.0.0; 
then 
	# Fix crash with `tcg.c:1693: tcg fatal error` by using a more recent version
	wget https://jguiraudet.github.io/assets/bin/qemu-arm-static
	chmod 755 ./qemu-arm-static
	sudo cp ./qemu-arm-static        root/usr/bin
else
	sudo cp /usr/bin/qemu-arm-static root/usr/bin
fi

# Create docker images
cd root
sudo tar -c . | sudo docker import - jguiraudet/raspbian-lite-for-x86_64:$DISK_IMG
cd ..

# Clean-up
sudo umount root
rmdir root
rm $DISK_IMG.img
sudo docker images | grep raspbian

echo Test the image with:
echo docker run -ti --rm jguiraudet/raspbian-lite-for-x86_64:$DISK_IMG /bin/bash -c \'uname -a\'
if docker run -ti --rm jguiraudet/raspbian-lite-for-x86_64:$DISK_IMG /bin/bash -c 'uname -a' | grep armv7l; then echo OK; else echo FAIL; fi