Debootstrap on i.MX6 Sabre Lite

My notes on installation of the root filesystem (RFS) on Freescale i.MX6 based SBCs (most on Boundary Devices BD-SL-i.MX6 aka Sabre Lite). This post was first written to document experiences with deboot-strapping Debian (Jessie), and since then I have also experimented with Ubuntu 13.10 Saucy, as it provided Xorg-server 1.14.6. Unfortunately I have not been able to get es2gears-x11 running on Ubuntu.

While making these notes I was following a debootstrap tutorial written for Olimex and did not bother repeating a lot of the details. I debootstrap the new rootfs on a spare card, using the same Sabre Lite board (running Debian Wheezy) as a host. The instructions on the Olimex blog include the details needed to bootstrap on a host of different architecture than the target.

I perform the installation with distro=jessie and use the following configuration of /etc/apt/sources.list to set my package sources to US servers:

cat << EOT > /etc/apt/sources.list
deb http://ftp.us.debian.org/debian/ $distro main contrib non-free
deb http://ftp.us.debian.org/debian/ $distro-updates main contrib non-free
deb http://security.debian.org/ $distro/updates main contrib non-free
EOT

My locale is en_US.UTF-8

While creating the RFS, I add a user in the standard way i.e. adduser debian.

Creation of /etc/fstab is absent from the instructions in the blog ... I use the following setup, which allows me to easily delete and re-install the RFS at a whim (important requirement for development), while keeping /home isolated from the RFS on it's own partition:

/dev/mmcblk0p1   /           auto   errors=remount-ro   0   1
/dev/mmcblk0p2   /home       auto   defaults            0   2

For Debian (see below for Ubuntu), the serial console login is enabled on Sabre Lite with the following line added to /etc/inittab:

T1:23:respawn:/sbin/getty -L ttymxc1 115200 vt102

One problem emerged with the first boot on the new RFS - the system failed to spawn a login process on the serial port (/dev/ttymxc1), although the login was working fine through the attached monitor/keyboard ... the following messages were observed on the serial console:

[ TIME ] Timed out waiting for device dev-ttymxc1.device.
[DEPEND] Dependency failed for Serial Getty on ttymxc1.

After enabling CONFIG_FHANDLE in my kernel (boundary-imx_3.10.17_1.0.0_ga) and rebuilding, I could login on the serial port.

With ethernet working and openssh-server already installed during the debootstrap process, I could get busy updating the system and installing some essential software packages:

apt-get install curl vim sudo gcc make bzip2 python lzop bc git libncurses5-dev
apt-get install flex libtool automake pkg-config bison 

There is one (apparently harmless) quirk observed with the new system:

[FAILED] Failed to start Login Service.
See 'systemctl status systemd-logind.service' for details.

This is possibly related to a bug in jessie. It seems that "standard system utilities" is not installed in the minimal debootstrap process - the bug report states that there is no negative effect on the boot process so long as the "System-V" init package is installed. A little more web crawling seems to indicate that there is something to do with tasksel, but I'm relatively new to Debian so leave it alone for now. (Update 1/22/2015 GN: noticed there is not a complete inittab installed so getty is not being called on tty[1-4])

Atheros WLAN working after firmware install:

usb 2-1.2: ath9k_htc: Failed to get firmware htc_9271.fw

(apt-get install firmware-atheros)


Here is some guidance on the u-boot parameters:

setenv bootargs console=${console},${baudrate} root=/dev/mmcblk0p1  rootfstype=ext4 rootwait video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off video=mxcfb4:off video=mxcfb5:off video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB16 fbmem=48M vmalloc=400 mxc_hdmi.only_cea=1 coherent_pool=48M

ext2load mmc ${mmcdev}:${mmcpart} ${fdt_addr} boot/${fdt_file}
ext2load mmc ${mmcdev}:${mmcpart} ${loadaddr} boot/${image}
bootz ${loadaddr} - ${fdt_addr}


For Ubuntu, the instructions are practically identical ... just a few differences.

sudo debootstrap --arch armhf saucy rootfs/

# etc/apt/sources.list:

deb http://ports.ubuntu.com/ubuntu-ports saucy main

#deb http://ports.ubuntu.com/ubuntu-ports/ saucy-updates main universe multiverse

deb http://ports.ubuntu.com/ubuntu-ports saucy universe # mesa-utils

Serial port is enabled as follows:

# /etc/init/serial.conf

start on stopped rc RUNLEVEL=[2345]

stop on runlevel [!2345]

respawn

exec /sbin/getty 115200 ttymxc1

Jury is still out as to which distro is better to get the GPU stuff working on i.MX6..