Panda How to kernel 3 2 rcx

Introduction
The merge window for 3.2 is over and the 3.2-rc1 kernel has been released. Lots of work on the omap platforms and on pandaboard. Let's see what -rc1 has brought.

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 v3.2-rcx

where x is the release candidate version

rc1
There are several issues requiring new patches. The WL12xx driver needs newer firmware, and the same patch as used for 3.1. 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.

rc2
There are no changes to OMAP or PandaBoard related code in the -rc2 release, or any fixes that would eliminate any of the patches required for -rc1, so we'll skip testing this release for a bit.

rc3
There were no changes to OMAP or PandBoard related code in the -rc3 release. The same patches required for -rc1 work for the -rc3 sources, and the kernel works as does the -rc1.

rc4
There were quite a few updates to OMAP code, but no PandaBoard related changes. The same patches required for -rc1 & -rc3 work for the -rc4 sources, and the kernel works as does the -rc1 & -rc3.

rc5
There were no changes to OMAP or PandBoard related code in the -rc5 release. The same patches required for -rc1, -rc3 & -rc4 work for the -rc5 sources, and the kernel works as well.

PandaBoard-ES
There is now a PandaBoare-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 therefor the max clock frequency when running the OMAP4460 on the PandaBoard ES with the mainline kernel is 920MHz(same as the OMAP4430).

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.

wlan12xx patch
This patch is necessary to resolve the issue noted in 3.0 and 3.1, the code was moved to twl_common.c and a patch is supposed to be in -rc2 or -rc3.

[[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

DVI Patch
A patch is no longer necessary to make 720p resolution available. The DVI driver now reads the EDID and sets the resolution on bootup if the display is plugged into the DVI connector. If the display is not plugged in on bootup it will default to 640 x 480.

I2C Patch
i2c character device driver patch that has been necessary is no longer required, however a couple of issues still need patching, so a new patch is required

[[Media:0002a-omap4-pandaboard-i2c.patch|0002a-omap4-pandaboard-i2c.patch]]

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

patch -p1 < 0002a-omap4-pandaboard-i2c.patch

USB Performance improvement
This patch fixs one performance bug on ARM Cortex A9 dual core platform, which has been reported on quite a few ARM machines (OMAP4, Tegra 2, snowball...), see details from link of https://bugs.launchpad.net/bugs/709245.

[[Media:0006-omap4-usb-improvement.patch|0006-omap4-usb-improvement.patch]]

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

patch -p1 < 0006-omap4-usb-improvement.patch

Building
Building 3.2-rc1,3,4,5 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 3.2-rc1,3,4,5 sources and use [[Media:config.3.2-rc1.1|config.3.2-rc1.1]], [[Media:config.3.2-rc3.1|config.3.2-rc3.1]], [[Media:config.3.2-rc4.1|config.3.2-rc4.1]] or [[Media:config.3.2-rc5.1|config.3.2-rc5.1]] as the .config (you should apply all the above patches)

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/3.2.0-rc1-dirty/ to your SD card (as root), boot up the Pandaboard. After 3.2-rc1, the kernel versioning was changed and the modules for -rc4,5 are now located in lib/modules/3.2.0-rc4-00002-gd3aebaf/ the last digits will change as the sources are edited, so your version numbers may differ.

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.