This file contains build and boot instructions for Enea Linux on
raspberrypi3-64, standard profile.

Build instructions
------------------
$ mkdir enea-linux
$ cd enea-linux
$ repo init -u git@git.enea.com:linux/manifests/el_manifests-standard.git \
    -b refs/tags/Enea_Linux_8.1 -m raspberrypi3-64/default.xml
$ repo sync
$ cd poky
$ TEMPLATECONF=meta-el-standard/conf/template.raspberrypi3-64 . \
    ./oe-init-build-env <build_dir>
$ bitbake enea-image-standard / enea-image-standard-sdk


Boot from RAM
-------------
Below you find an example that requires a TFTP server set up at IP address
<tftp_server_ip>, and that the server stores the Enea Linux image files,
kernel image, device tree blob and root filesystem, in
/tftpboot/<download_directory>. 

Once you have that in place, run the following commands on the target:

## set tftp server IP
U-Boot> setenv serverip <tftp_server_ip>

## tftp the image files on the target machine
U-Boot> tftpboot 0x01000000 Image  
U-Boot> tftpboot 0x02000000 Image-bcm2837-rpi-3-b.dtb 
U-Boot> tftpboot 0x03000000 enea-image-standard-raspberrypi3-64.ext2.gz.u-boot

## add any other bootargs values if necessary 
U-Boot> setenv bootargs "8250.nr_uarts=1 root=/dev/ram rw ramdisk_size=500000
ip=dhcp \
console=ttyS0,115200"

## Start boot sequence
U-Boot> booti 0x01000000 0x03000000 0x02000000



Boot from SD card
-----------------
Copy the enea-image-standard-raspberrypi3-64.rpi-sdimg image to the SD card
using the Linux dd tool or Win32DiskImager in Windows, and insert it into the
RPi. The Raspberry Pi will not start without a properly formatted SD Card,
containing the bootloader, kernel image and rootfs.

Below you can find two methods of how to format an SD Card:

1. Format and copy images to the SD card using the Linux dd command line

    The dd command copies a file, converting the format of the data in the
process, according to the operands specified:

    $ sudo dd bs=4M if=enea-image-standard-sdk-raspberrypi3-64.rpi-sdimg of=/dev/sdg

Note:
    Use dd cautiously - improper usage or entering the wrong values could
inadvertently wipe, destroy, or overwrite the data on your hard drive.

2. Format the SD card using the Win32DiskImager program

    1) Download and unzip Win32DiskImager
    2) Run Win32DiskImager.exe
    3) Select the drive of your SD card
    4) Select the image enea-image-standard-raspberrypi3-64.rpi-sdimg
    5) Click "Write" and wait for the write to complete
    6) Exit the imager and eject the SD Card
    7) Plug the card into your Raspberry Pi

Note:
    Be careful to select the correct drive. If you choose the wrong one you may
destroy your HDD data. If you are using an SD Card slot and can't see the
drive in the Win32DiskImager window, try using an affordable external adapter
in a USB slot.