Panda How to kernel 3 3 rcx

Introduction
The merge window for 3.3 is over and we are currently at v3.3-rc1. Lots of work on the OMAP platforms and on Pandaboard. Let's see what the various release candidates have provided.

You can download a tarball of the mainline kernel at http://kernel.org/

or you can clone a copy of mainline kernel with:

git clone http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git cd linux git checkout v3.3-rcx

where x is the release candidate version.

rc1
The WLAN still requires a patch. The WL12xx driver needs current firmware, and the same patch as used for 3.1 and 3.2 works. When the driver isn't happy, the error messages are somewhat less than useful, however the drivers/firmware are being constantly improved and it would not be a good idea to have the driver support anything but the latest firmware. Still a work in progress.

PandaBoard ES
There is now a PandaBoard ES http://pandaboard.org/content/pandaboard-es which includes an OMAP 4460 at up to 1.2GHz. Several important differences make it important (at the present time) that the MLO/u-boot be specifically crafted for the 4460. The thermal management is not in the mainline 4430 code as yet and therefore the max clock frequency when running the OMAP4460 on the PandaBoard ES with the mainline kernel is 920MHz(same as the OMAP4430).

wlan12xx
The latest wlan firmware is available from git: git://git.kernel.org/pub/scm/linux/kernel/git/dwmw2/linux-firmware.git just copy the contents of the ti-connectivity folder to /lib/firmware/ti-connectivity.

This patch is still necessary to resolve the issue noted in 3.0, 3.1 and 3.2.

[[Media:0001a-omap4-pandaboard-wlan-fix.patch|0001a-omap4-pandaboard-wlan-fix.patch]]

Apply it like so: (from inside the kernel sources directory)

patch -p1 < 0001a-omap4-pandaboard-wlan-fix.patch

I2C Patch
i2c character device driver patch that has been necessary is no longer required, and the issues from kernel 3.2 have been resolved.

Building
Building 3.3-rc1 is a bit different from previous How-To's if you want to have a working wlan.

In order to ensure that the wlan starts up consistently, it is recommended that the wl12xx driver be built as a module and started after the PandaBoard has booted.

Grab the 3.3-rc1 sources and use [[Media:config.3.3-rc1.1|config.3.3-rc1.1]] as the .config (you should apply the above patch)

This .config enables Sound so the resulting kernel will be a bit bigger than previously.

Then compile like so:

make ARCH=arm CROSS_COMPILE=Path_to_your/arm-2010q1/bin/arm-none-linux-gnueabi- uImage

Then compile the modules like so:

make ARCH=arm CROSS_COMPILE=/home/kenm/Panda/arm-2010q1/bin/arm-none-linux-gnueabi- modules

"Install" the modules to somewhere convenient:

make ARCH=arm CROSS_COMPILE=/home/kenm/Panda/arm-2010q1/bin/arm-none-linux-gnueabi- INSTALL_MOD_PATH=../testlib_omap modules_install

Copy lib/modules/3.3.0-rc1-dirty/ to your SD card (as root), boot up the Pandaboard.

fbtest on DVI Port
After booting run fbtest to see a nice test pattern from the dvi port.



Switching primary display to the HDMI port
Make sure that a monitor is plugged into the HDMI port before doing the following:

echo "1" > /sys/devices/platform/omapdss/display1/enabled echo "0" > /sys/devices/platform/omapdss/overlay0/enabled echo "tv" > /sys/devices/platform/omapdss/overlay0/manager echo "1" > /sys/devices/platform/omapdss/overlay0/enabled
 * 1) Enable HDMI
 * 1) Disable overlay0 (an overlay must be disabled before changing its properties)
 * 1) Set the manager of overlay0 to display1 which is HDMI
 * 1) Enable overlay0

And content on overlay 0 of primary lcd would be transferred to HDMI. It works similarly for all other overlay's.

Switching primary display to the DVI port
See: http://omappedia.org/wiki/Bootargs_for_enabling_display for lots of useful info on the display subsystem. Be aware that the display, manager and overlay numbers don't match the panda configuration.

Make sure that a monitor is plugged into the DVI port before doing the following:

echo "0" > /sys/devices/platform/omapdss/display1/enabled echo "0" > /sys/devices/platform/omapdss/overlay0/enabled echo "lcd2" > /sys/devices/platform/omapdss/overlay0/manager echo "1" > /sys/devices/platform/omapdss/overlay0/enabled
 * 1) Disable HDMI
 * 1) Disable overlay0 (an overlay must be disabled before changing its properties)
 * 1) Set the manager of overlay0 to display0 which is DVI
 * 1) Enable overlay0

The above commands should be run from the serial console and the cable should be in the destination port before running the commands.

fbtest on HDMI Port
Run fbtest to see a nice test pattern from the HDMI port.



i2cdetect
You can run i2cdetect and the results should look like this:

0 1  2  3  4  5  6  7  8  9  a  b  c  d  e  f 00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --  30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --  40: -- -- -- -- -- -- -- -- UU UU UU UU -- -- -- -- 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --  70: -- -- -- -- -- -- -- --
 * 1) i2cdetect -y -r 1

wlan
Run the following commands after the PandaBoard is booted:

modprobe wl12xx_sdio ifconfig wlan0 up iwconfig wlan0 essid "Your AccessPoint Name" udhcpc -i wlan0

If your network is set up to provide DHCP services, the PandaBoard will get all the "right stuff(tm)" and you will be able to access the Internet.

PING www.google.com (74.125.73.99): 56 data bytes 64 bytes from 74.125.73.99: seq=0 ttl=43 time=62.683 ms 64 bytes from 74.125.73.99: seq=1 ttl=43 time=54.077 ms 64 bytes from 74.125.73.99: seq=2 ttl=43 time=51.484 ms 64 bytes from 74.125.73.99: seq=3 ttl=43 time=54.108 ms
 * 1) ping www.google.com

USB Performance
Insert a USB memory stick into one of the usb ports

Run dmesg to see what sdx the stick was recognised as, then:

hdparam -tT /dev/sdx

If you did this on a kernel without the patch you will see some improvement, if you run the same command on a desktop Linux system, with the same USB memory stick, the PandaBoard's speed should roughly be the same.