nv-uboot on Chromebook2

gistfile1.txt

1) Enter Developer Mode

Disclaimer. I will take no responsibility if you somehow brick your chrome book. You should only attempt the following if you are familiar with embedded system hackery :)

With the laptop turned off, hold down the escape and refresh keys, then press the power key

The device is now in Recovery Mode, pressing Ctrl-D will enable Developer Mode.

Confirm the action by pressing Enter.

On the next boot of the laptop press Ctrl-D once again on the OS verification is OFF screen.

The laptop will then start preparing itself for Developer Mode. Every time you turn on the device press Ctrl-D to boot the default installation of Chrome OS.

2) Prepare SD card

 DEV=/dev/sdb (Make sure this is your SD card device, as this is just an example)

 # Create a fresh GPT label on the SD card
 parted $DEV mklabel gpt

 # Create first kernel partition  (A) (16MB)
 cgpt add -b 8192 -s 32768  -t kernel -l "KERN-A" $DEV

 # Create second Kernel parition (B) (16MB)
 cgpt add -b $((8192 + 32768)) -s 32768  -t kernel -l "KERN-B" $DEV

 # root fs, remainder 15523807 is where my 8G sdcard had the start of the
 # secondary gpt partition. Use cgpt show /dev/mmcblk0 to check
 cgpt add -b $((8192 + 32768 + 32768)) -s $((15523807 - (8192 + 32768 + 32768))) -t rootfs -l "root" $DEV

 # Tell the bootloader to boot from the first parition
 cgpt add -i 1 -T 2 -P 10 -S 1 $DEV

3) Burn nv-uboot

# For the peach-pi download this nv-uboot
https://drive.google.com/file/d/0B9DbsE2BbZ7ubUxHOUduTFlpeFk/edit?usp=sharing

# Burn nv-uboot to the sdcard
 DEV=/dev/sdb (Make sure this is your SD card device, as this is just an example)
 PART=1  
 dd if=images/nv_uboot-peach-pi.kpart of=${DEV}${PART}

4) Install rootfs

# Mount partition three
mkdir tmp
mount /dev/sdb3 tmp/

# Debootstrap filesystem
debootstrap --arch=armhf sid tmp/ (I did this on an ARM platform so use you are on a different architecture you will need to use the --foreign flag)

# Setup the console
echo T0:23:respawn:/sbin/getty -L ttySAC3 115200 vt102 >> /etc/inittab
echo >> /etc/securetty
echo ttySAC3 >> /etc/securetty

# Download the kernel image or build the kernel image
https://drive.google.com/file/d/0B9DbsE2BbZ7uMVRXbUZVSDZyQWM/edit?usp=sharing

https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-3.8

# Install kernel image onto / of root file system
cd tmp/
cp /path/to/uImage .

# Umount filesystem
umount tmp/

4) Insert card into SD slot on Chromebook2 and boot nv-uboot

# Power on

# Ctrl-U to launch nv-boot

5) Configure nv-uboot

# Set bootfile name
setenv bootfile uImage

# Load kernel
ext2load mmc 1:3 ${loadaddr}

# Set kernel arguments
setenv bootargs console=tty1 root=/dev/mmcblk1p3 rw

# Boot it!
bootm ${loadaddr}