Please check http://g-lab.ca for instructions to build a kernel 3.12-rc2

Latest Stable Kernel 3.7.1 include USB support for imx23-olinuxino boards. This
build contain patches for SPI and I2C interface and also patches for easy kernel
integration of wifi rtl8188cu device. You can download precompiled image from here:
https://www.dropbox.com/s/rfnmzdbcu21pfgf/sd_mmc_bootstream.raw

Cross compiler and git.

On Debian distributions install as:

$: sudo apt-get install gcc-arm-linux-gnueabi
$: sudo apt-get install git

SD card with two partition:

• boot partition for kernel, and -rootfs partition with your prefered linux distribution.
  See file Make bootable SD-Card for instructions how to make the two partition SD card

$: git clone https://github.com/koliqi/imx23-olinuxino  

This package contain also:

• Freescale imx-bootlets and utility elftosb2,
• patches for imx-bootlets.

Freescale imx-bootlets and utility elftosb2 are from Freescale package L2.6.31_10.05.02_ER_source.
Utility elftosb2 is distributed in binary form. Sources can be found at the following link:
http://repository.timesys.com/buildsources/e/elftosb/elftosb-10.12.01/

Directory tree is as follows:

├── boot
│   ├── 0001-boards-Add-support-for-imx233-olinuxino-board.patch
│   ├── elftosb-0.3
│   │   ├── elftosb2
│   │   └── Makefile
│   ├── imx23_olinuxino_bootlets.patch
│   └── imx-bootlets-src-10.05.02.tar.gz
├── kernel
│   ├── 0001-ARM-imx23-olinuxino-Add-spi-support.patch
│   ├── 0001-MXS-imx23-olinuxino-Add-i2c-support.patch
│   └── 0001-rtl8192cu.patch
├── Make bootable SD-Card.md
├── README.md
└── rootfs

1. Building a kernel from sources
   ===

Switch into directory kernel and download kernel sources:

$: cd imx23-olinuxino/kernel  
$: wget http://www.kernel.org/pub/linux/kernel/v3.0/linux-3.7.1.tar.bz2
$: tar xvjf linux-3.7.1.tar.bz2
$: mv linux-3.7.1 linux-stable  

New directory linux-stable contain kernel sources. Switch into directory linux-stable to apply patches.

$: cd linux-stable  
$: patch -p1 < ../0001-MXS-imx23-olinuxino-Add-i2c-support.patch  
$: patch -p1 < ../0001-ARM-imx23-olinuxino-Add-spi-support.patch  
$: patch -p1 < ../0001-rtl8192cu.patch  

Start from supplied default mxs_defconfig configuration:

$: make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- mxs_defconfig  
$: make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- menuconfig  

Select Boot options ---> and select following options:

 Boot options ---->  
  [*]  Use appended device tree blob to zImage (EXPERIMENTAL)  
  [*]   Supplement the appended DTB with traditional ATAG information  
(console=ttyAMA0,115200 root=/dev/mmcblk0p2 rw rootwait)  Default kernel command string  

Users of imx23-olinuxino-maxi need to enable the smsc95xx driver in the kernel configuration,
otherwise you won't get your network up in the olinuxino.

       -> Device Drivers  
         [*] Network device support  --->  
                   USB Network Adapters  --->   
                         <*> Multi-purpose USB Networking Framework  
                         <*> SMSC LAN95XX based USB 2.0 10/100 ethernet devices

Users of imx23-olinuxino-mini need to enable driver rtl8188cu:

Enable Multi-purpose USB Networking Framework:

       -> Device Drivers  
         [*] Network device support  --->  
                   USB Network Adapters  --->   
                         <*> Multi-purpose USB Networking Framework   

then activate IEEE 802.11 networking stack:

		[*] Networking support  --->  
                                   [*]   Wireless  ---> 
                                   <*>   cfg80211 - wireless configuration API  
                                   [ ]     nl80211 testmode command  
                                   [ ]     enable developer warnings  
                                   [ ]     cfg80211 regulatory debugging  
                                   [ ]     enable powersave by default  
                                   [ ]     cfg80211 DebugFS entries  
                                   [*]     cfg80211 wireless extensions compatibility  
                                  < >   Common routines for IEEE802.11 drivers  
                                  <*>   Generic IEEE 802.11 Networking Stack (mac80211)  

and activate Realtek 8192C USB WiFi and IEEE 802.11 for Host AP:

     -> Device Drivers  
        [*] Network device support  --->  
                     [*]   Wireless LAN  --->  
                     <*>   Realtek 8192C USB WiFi  
                     <*>   IEEE 802.11 for Host AP (Prism2/2.5/3 and WEP/TKIP/CCMP)  

Power LED need to have default ON trigger activated on kernel:

       -> Device Drivers  
         -> LED Support  
             <*>   LED Default ON Trigger  

Activate other drivers as needed. Save and exit from menuconfig application.

$: make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- zImage modules  

Kernel is ready at arch/arm/boot/zImage.

Create device tree blob .dtb file:

$: make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- imx23-olinuxino.dtb  

Join zImage and imx23-olinuxino.dtb into a new file zImage_dtb:

$: cat arch/arm/boot/zImage arch/arm/boot/imx23-olinuxino.dtb > arch/arm/boot/zImage_dtb  

If you want to repeat this procedure, start with clean-up:

$: make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- distclean  
$: make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- clean  

2. Bootlets
   ===

The iMX23 SoC contains a built-in ROM firmware capable of loading and
executing binary images in special format from different locations including
MMC/SD card and NAND flash. Binary image is called a boot stream (.bs).
Boot stream consists of a series of smaller bootable images (bootlets)
such clock bootlet, power bootlet etc.
Linking bootlets with kernel and converting from elf format to raw boot stream is
done with utility elftobs. In this package, utility elftobs2 is located in directory elftosb-0.3.

Switch into directory elftosb-0.3 and make symbolic link into compilers default
PATH:

$: sudo ln -s `pwd`/elftosb2 /usr/sbin/  

Check with locate:

$: locate elftosb2  

elftosb2 should be located at /usr/sbin/elftosb2.

Next, switch into directory boot and untar archive imx-bootlets-src-10.05.02.tar.gz

$: tar xvzf imx-bootlets-src-10.05.02.tar.gz  

then switch into directory imx-bootlets-src-10.05.02 and apply patches:

$: patch -p1 < ../imx23_olinuxino_bootlets.patch  

This patched package require zImage in this directory. We have created
zImage_dtb instead, so make symbolic link as:

$: ln -s ../../kernel/linux-stable/arch/arm/boot/zImage_dtb ./zImage  

Make boot stream file:

$: make CROSS_COMPILE=arm-linux-gnueabi-  clean  
$: make CROSS_COMPILE=arm-linux-gnueabi-  

Final response would be:

To install bootstream onto SD/MMC card, type: sudo dd if=sd_mmc_bootstream.raw of=/dev/sdXY     where X is the correct letter for your sd or mmc device (to check, do a ls /dev/sd*) and Y is   the partition number for the bootstream  

In my system sd device is /dev/sdb1, so writing bootstream file in card is done by:

$: sudo dd if=sd_mmc_bootstream.raw of=/dev/sdb1  

Card is ready.

It is good practice to work with multiple consoles. Open one into directory linux-mainline,
second into imx-bootlets-src-10.05.02 and third console for minicom to monitor olinuxino.

If olinuxino failing to boot because of the error:

Undefined Instruction 
r14_unHTLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLFC   

Probably your toolchain does not support cpu arm926ej-s. Download sources and
compile --with-arch=armv5te --with-tune=arm926ej-s. If you prefer premade binaries,
download arm-none-eabi toolchain. It is proven to work with arm926ej-s.

Add PPA in your system:

$: sudo add-apt-repository ppa:germia/archive3  

Refresh list of software available, including the PPA you just added:

$: sudo apt-get update  

Install packages:

sudo apt-get install gcc-arm-none-eabi binutils-arm-none-eabi \  
newlib-arm-none-eabi \  
gdb-arm-none-eabi  

Instead of CROSS_COMPILE=arm-linux-gnueabi- write CROSS_COMPILE=arm-none-eabi-
and follow instructions in section 1) and 2).

*) i.MX23 Linux BSP User’s Guide, Freescale Rev. 10.05.03, 05/2010