path: root/TI_OMAP4_Kernel_Release_Notes_L24.x.txt

07 May 2010


1.  Introduction
----------------
This document accompanies OMAP(TM) Software Release L24.6 for Linux 2.6.33-rc2
on OMAP4430 SDP. The document specifies:
	- Instructions for unpacking the release
	- New features and features the release supports
	- Planned future features
	- Postponed features


2. Release Summary
------------------
This is a release of the Linux Baseport for OMAP4430. It supports the
OMAP4 Wakeup SDP board. The kernel is based on Linux-omap version 2.6.33-rc2
from open source. U-boot is based on open-source version 1.1.4.

The u-boot source can be obtained via GIT from:
  http://dev.omapzoom.org/?p=bootloader/u-boot.git;a=shortlog;h=refs/heads/omap4_dev

The x-loader source can be obtained via GIT from:
  http://dev.omapzoom.org/?p=bootloader/x-loader.git;a=shortlog;h=refs/heads/omap4_dev

The kernel source can be obtained via GIT from:
  http://dev.omapzoom.org/?p=integration/kernel-omap4.git;a=shortlog;h=refs/heads/L24.6

Components that are supported in the release:
   X-loader, U-Boot, OS Kernel (SMP), Phoenix power IC, UART, GP Timer, GPIO, Watchdog,
   Neon, I2C, MMC/SD/eMMC (with ADMA support), Ethernet, RTC,
   SDMA (including descriptor loading), Keypad, Touch screen, McSPI, McBSP, Mentor USB,
   Phoenix General Purpose ADC, Battery Charging, Power Management Frameworks,
   Audio (Phoenix Audio IC, ABE, AESS),
   Display driver (TAAL based), Basic display (DSS2 migration, FB dev), Tiler memory manager.
   WLAN support


3.  Instructions
----------------

3.1 Board setup

Please refer to the OMAP4430 SDP guide for instructions on setting up the OMAP4
board.

3.2 Compiling Images

3.2.1 Compiling U-boot

Set the environment variable PATH such that cross compile binaries point to the
needed tool chain. Refer to section 5 for tool chain information.

To select the default configuration for U-Boot type:
	# make CROSS_COMPILE=arm-none-linux-gnueabi- omap4430sdp_config

To build the U-Boot image type:
	# make CROSS_COMPILE=arm-none-linux-gnueabi-


3.2.2 Compiling X-loader (for booting from external/removable MMC)

Set the environment variable PATH such that cross compile binaries point to the
needed tool chain. Refer to section 5 for tool chain information.

U-boot needs to be placed in a directory parallel to x-loader and compiled first.
E.g.:
	[DIR] omap4
		+-- u-boot
		+-- x-loader

To select the default configuration for X-loader type:
	# make CROSS_COMPILE=arm-none-linux-gnueabi- omap4430sdp_config

To build the X-loader image type:
	# make CROSS_COMPILE=arm-none-linux-gnueabi-
	# make ift CROSS_COMPILE=arm-none-linux-gnueabi-

The above step will create a MLO image, which can be copied into the
MMC card for booting via MMC.

3.2.3 Compiling X-loader (for booting from eMMC)

Follow same steps as above to create an MLO image. A configuration header needs
to be added at the begining of this MLO to create an image 'x-load.ch.bin' that
can be written to the eMMC for eMMC-booting. Please contact your TI
representative for obtaining the configuration header.

3.2.4 Compiling the Kernel

Set the environment variable PATH such that cross-compile binaries point to the
needed tool chain. Refer to section 5 for tool chain information.

The default configuration file for OMAP 4430 is present at
arch/arm/configs/omap_4430sdp_defconfig.

To work with the default configuration file, run following commands:
	# make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabi-
					omap_4430sdp_defconfig

Build kernel with:
	# make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabi- uImage

NOTE:	The above steps will create arch/arm/boot/uImage in the kernel directory
	which is the binary used for booting.

3.3 Flashing and Booting

3.3.1 Booting from removable MMC

Use the MLO (ref: section 3.2.2) and u-boot.bin (ref: section 3.2.1) binaries
and follow the instructions at http://elinux.org/BeagleBoard#MMC.2FSD_boot
to boot the board from removable MMC.

Set the board switch settings as follows to boot the board from removable MMC:
	S9 - 1-off, 2-on, 3-on, 4-on
	S8 - 1-off, 2-on, 3-off, 4-on, 5-on, 6-on, 7-on, 8-on

3.3.2 Flashing and booting from eMMC

Follow the instructions below to save x-loader and u-boot binaries to eMMC and
subsequently boot from eMMC.

Get the x-loader and u-boot binaries (that you want to flash to eMMC) into RAM
using one of the following options.

Option 1:
Use a debugger or OMAPFlasher tool to download x-loader (with configuration
header, e.g. x-load.ch.bin) as well as u-boot.bin into
SDRAM and run u-boot from SDRAM.

Option 2:
Boot via a removable MMC card following the instructions in section 3.3.1, but
additionally keep the x-load.ch.bin that you want to flash to eMMC in the same
removable MMC card. After booting from removable MMC, copy the x-load.ch.bin
and u-boot.bin from the MMC to RAM using the following commands:
OMAP44XX SDP # mmcinit 0
OMAP44XX SDP # fatload mmc 0 [Ram Address X] x-load.ch.bin
OMAP44XX SDP # fatload mmc 0 [Ram Address Y] u-boot.bin

Once the x-loader and u-boot binaries are in RAM, use the following commands
to copy them to eMMC.

1) Erase all EMMC contents
OMAP44XX SDP # mmcinit 1
OMAP44XX SDP # mmc 1 erase 0x0 0x800000
2) Flash x-loader
OMAP44XX SDP # mmc 1 erase  0x100  [size of x-loader in hex]
OMAP44XX SDP # mmc 1 write [Ram Address X]  0x100  [size of x-loader in hex]
Note: Ram address X is address where x-loader is downloaded in RAM using either the
debugger, OMAPFlasher or removable MMC.
3) Flash u-boot.bin
OMAP44XX SDP # mmc 1 erase  0x400  [size]
OMAP44XX SDP # mmc  1 write  [Ram Address Y]  0x400  [size]
Note: Ram address Y is address where u-boot is downloaded in RAM using either the
debugger, OMAPFlasher or removable MMC.

Set the board switch settings as follows to boot the board from eMMC:
	S9 - 1-off, 2-on, 3-on, 4-on
	S8 - 1-on, 2-on, 3-on, 4-on, 5-on, 6-off, 7-on, 8-on

3.3.3 Using Filesystem from eMMC

Use fdisk to create an ext2 partition (/dev/mmcblk0p2) in eMMC leaving 2MB of space
at the top.

Use the following commands to flash the filesystem to eMMC partition
1) Bootup with a known good kernel and filesystem from RAM
2) Use a filesystem which has USB Gadget filestorage module g_filestorage.ko
3) Connect the usb cable from the board to the PC
4) Load the USB filestorage gadget module as:
insmod g_filestorage.ko file=/dev/mmcblk0p2 stall=0 removable=1
5) When the USB drive enumerates on the Linux PC, mount the drive
6) Add ext2 filesystem to the mounted drive
7) sync and then mount the drive.
8) Add the following in bootargs "root=/dev/mmcblk0p2 rw rootdelay=1" to be able
to use the eMMC based FS as rootfs.

3.3.4 Bootargs

Since UART3 is used as the console on OMAP4 Wakeup board, you need to set
'console=ttyO2,115200n8' in the bootargs

While using a filesystem from MMC or eMMC, you may use params such as:
'root=/dev/mmcblk1p2 rw rootdelay=1'. The rootdelay is required because
removable cards may take a few seconds to be detected.

Also note that 'root=/dev/mmcblkXp2' where "x" means 1 or 2 depending if you
use MMC as default this should be 1 or eMMC should be 0.

While using a filesystem via NFS, you may use params such as:
'root=/dev/nfs rw nfsroot=<serverip>:<mount-partition>,nolock'

Refer to section 3.4.2 for display related bootargs options

For detailed list and explaination of the various boot parameters, please refer
http://www.kernel.org/pub/linux/kernel/people/gregkh/lkn/lkn_pdf/ch09.pdf


3.4 Using FB and V4L2 Display driver

3.4.1 To enable secondary display

Please use following set of commands after kernel bootup for setting
secondary display ON.

1) Enable secondary display (display1)
	echo "1" > /sys/devices/platform/omapdss/display1/enabled
2) Disable overlay1
	echo "0" > /sys/devices/platform/omapdss/overlay1/enabled
3) Attach secondary display as a manager for overlay1
	echo "2lcd" > /sys/devices/platform/omapdss/overlay1/manager
4) Enable overlay1
	echo "1" > /sys/devices/platform/omapdss/overlay1/enabled

3.4.2 Display specific bootargs options

3.4.2.1 Using 1 FB and 3 V4L2 devices
Add the following in bootargs "omapfb.numfb=1"

3.4.2.2 Using 2 FB and 2 V4L2 devices (default option in L24.2 onwards)
Add the following in bootargs "omapfb.numfb=2"

3.4.2.3 Enabling DSS DEBUG prints
Add the following in bootargs "omapdss.debug=1"

3.4.3 Pico DLP support

OMAP4 device supports a pico DLP and secondary LCD output on the secondary
LCD manager (with the name of '2lcd').  The configuration of the display
happens in a non-conventional way.

3.4.3.1 For building kernel image with Pico DLP support:
	In menuconfig following "pico DLP" option needs to be set
	Device drivers ->
		Graphics support ->
			OMAP 2/3 Diaplay subsystem support ->
					omap 2/3 display drivers ->
					<*> pico DLP 
3.4.3.2 After bootup:

To configure output to either pico DLP or secondary LCD, set the overlay's
manager to the secondary LCD manager:

echo "0" > /sys/devices/platform/omapdss/overlay0/enabled
echo "2lcd" > /sys/devices/platform/omapdss/overlay0/manager
echo "1" > /sys/devices/platform/omapdss/overlay0/enabled

3.4.3.3	Then enable the correct display to chose pico DLP or secondary LCD (default
is secondary LCD).  Assuming display1 is secondary LCD, and display3 is
pico DLP:

echo "0" > /sys/devices/platform/omapdss/display1/enabled
# set the secondary manager to pico DLP
echo "pico_DLP" > /sys/devices/platform/omapdss/manager2/display -- This will set secondary manager to pico.
echo "1" > /sys/devices/platform/omapdss/display3/enabled

3.4.3.4	Now to switch back to secondary 
echo "0" > /sys/devices/platform/omapdss/display3/enabled
echo "2lcd" > /sys/devices/platform/omapdss/manager2/display
echo "1" > /sys/devices/platform/omapdss/display1/enabled

3.5 Enabling Power Management Features

All PM features are disabled in the default OMAP4 kernel configuration
(omap_4430sdp_defconfig).
All clocks are still kept enabled on bootloader.

To test PM features please use omap4_pm_defconfig. Note that PM features
on OMAP4430 ES1.0 can only be verified on a EMU device. The EMU device needs
the x-loader signed with the right PPA release.

omap4_pm_defconfig does not enable Tick suppression. To do so enable these
options manually.

Enable the following options in menuconfig
	Kernel Features ---> Use local timer interrupts
	Kernel Features ---> Tickless System
	Kernel Features ---> High Resolution Timer support

omap4_pm_defconfig has VFP support disabled due to a know issue with enabling
FPU on ES1. Please do not enable VFP support.

3.5.1 CPU Hotplug

To hotplug out CPU1 use the following command

echo 0 > /sys/devices/system/cpu/cpu1/online

To bring back CPU1 online use the following command

echo 1 > /sys/devices/system/cpu/cpu1/online

Note that CPU0 cannot be offlined due to hardware limitation.
Currenlty CPU1 transitions to CSWR state when offlined. This can
only be verified using OBS signals.

3.5.2 CPUIdle

To test cpuidle, it's necessary that CPU1 is hotplugged out.
Use the below command to hotplug out CPU1
echo 0 >  /sys/devices/system/cpu/cpu1/online

Once CPU1 is hotplugged out, OBS signals can be used to
verify MPU/CPU0/CPU1 transtitions.

Currently only sleep state of MPU CSWR is supported.

3.5.3 System Suspend

To test system suspend, use the following command

echo mem > /sys/power/state

Use OBS signals to verify MPU/CPU0/CPU1 transitions.

Currently only sleep state of MPU CSWR is supported.

Please use a ramdisk inorder to test system suspend feature

3.6 Using Audio Driver

Include the asound.conf file in /etc directory in your FS. It maps the different
audio devices 

Usage:
aplay -D mm file.wav
aplay -D tones file.wav
aplay -D vx file.wav
aplay -D hd_audio file.wav



4. Features
-----------

4.1 New Features

- Bootloader

	- Ability to save environment parameters is now added to u-boot
 
          Adding feature for saving environment Vairables which stores them
          permanently to persistent storage device which is currently eMMC on
          OMAP4430SDP and doesn't save on removable MMC.

          The environment variables  are stored on RAW partition of size 1MB on eMMC 
          starting from sector 0x700 to sector 0x7FF.

          Currently "saveenv" is replaced with "emmcsaveenv" and  has been modified so
          as to make the user aware of the fact that the environment will be written to eMMC.
          Also If the eMMC is already formatted and if any of the partition falls within sectors allocted 
          for "env" and using the "emmcsaveenv" command will result in over writing the partition.

- Power Management Frameworks
	- Clock framework
	- Clockdomain framework
	- Powerdomain framework
	- Regulator framework
	- CPUidle with support upto MPU CSWR
	- System wide suspend with support upto MPU CSWR
	- CPU1 hotplug with support upto CPU1 CSWR
NOTE:
	- All PM features are disabled in the default OMAP4 kernel configuration.
	- All clocks are still kept enabled on bootloader.
	- These features can only be validated on EMU devices with omap4_pm_defconfig

- Audio
	- Audio Playback to Phoenix Earphone
	- Audio Playback using Tones port
	- ALSA controls for ABE mixers
	- Add McPDM power management support

4.2 Supported Features

- Boot-loader:
	X-loader with MMC/eMMC/SD support
	U-boot with USB, MMC/eMMC/SD and Ethernet support

- OS Kernel
	OS Kernel (SMP)
	Phoenix power IC,
	UART,
	GP Timer,
	GPIO,
	Watchdog,
	NEON,
	I2C,
	MMC/SD/eMMC (with ADMA support),
	Ethernet,
	RTC,
	SDMA (including descriptor loading),
	Keypad,
	Touch screen,
	McSPI,
	McBSP,
	Mentor USB,
	Phoenix General Purpose ADC,
	Battery Charging.

- Audio
	Audio playback to Phoenix Hand-free, Head set output devices.
	HDMI audio playback
	Audio record through Phoenix analog MIC input.
	Simultaneous audio playback and capture.

- Video
	Display driver
		- FBdev and V4L2 API support
		- Primary and Secondary DSI and HDMI displays
		- Simultaneous rendering on all 3 displays
	Tiler memory manager.

- WLAN

4.3 Postponed Features

None

4.4 Future Planned Features

Refer to Program schedule.

4.5 Defects Fixed in This Release

OMAPS00216357   Packet loss in multiple ICMP transfers
OMAPS00211463   NFS speed is too slow in L24x
OMAPS00214519   After boot SATO image and Calibrate Touchscreen if the screen is touched X-server crashes.
OMAPS00216449   Problems are seen with NFS when 'tcp' option is not specified in bootargs.
OMAPS00213823   Keypad driver doesn't work as module if clock changes are added 
OMAPS00216309   IRQ Affinitty not available for driver
OMAPS00216312   Touchscreen irq cannot be handled in processor 2
OMAPS00216899   Non Working Touchscreen Interface in Poky UI
OMAPS00213925   TestSuites: SMP: Process Priority: sched entry missing

Known Issues:

OMAPS00216391	With tearing effect patch , frame drops from 60fps to 30fps
OMAPS00216592	There is no way available for dynamically setting/resetting dithering bit
OMAPS00213907	With omapfb.numfb=1 in bootargs , the rest of pipelines are not given to v4l2
OMAPS00214116	Visible tearing during the execution of a 3D app with flipping enabled.
OMAPS00215432	CONFIG_PANEL_4430SDP_TAAL lacks config dependency on DSS_DSI
OMAPS00216002	DSS function default_wait_vsync doesn't distinguish between primary and secondary LCD panels
OMAPS00216444	Provide KConfig options for DSI2, Sec Taal panel, and all DSI specific knobs
OMAPS00216589	VGA Rotation on LCD does not work
OMAPS00216585	V4L2 Rotation ioctls rotate 90 degrees when set to 270 degress and vice versa
OMAPS00216582	streaming test case gives issue when multiple buffers are used in the videobuf queu

4.6 Open Defects

OMAPS00214519  After boot SATO image and Calibrate Touchscreen, if the screen is touched X-server crashes.
OMAPS00215651  MUSB driver in host mode has problems with unaligned DMA
OMAPS00215668  MUSB driver in device mode has problems with unaligned DMA.
OMAPS00216037  L24x: CPUx comes out of low power mode when there is an enevt om CPUy
OMAPS00216039  L24x: Tick suppression won't work because of the LOCAL A9 timer aren't wakeup capable
OMAPS00216393  DMA testcases should declare set_test_passed(1) only during rmmod
OMAPS00217332  USB does not work if SYSBOOT settings are such that USB is never attempted during bootup
OMAPS00218005  MUSB Host does not work reliably when PIO mode is used.
OMAPS00213836  OMAP4 u-boot: i2c TimeOuts at speed 400Khz, 2100Khz
OMAPS00218007  OMAP4 RTC: Unable to set IRQ affinity to cpu0/1
OMAPS00216470  Linux Test Projects, Miscellaneous Failures Opened


4.7 Open Change Requests

None

4.8 Rejected Defects

None

4.9 Postponed Defects

OMAPS00213825   Kernel crash when many processes have been scheduled
                Postponed, Cannot reproduce a second time
OMAPS00214020   ethernet doesn't get configured with L24.4 kernel Postponed
                Postponed, Cannot reproduce in current release


4.10 Limitations

1) At u-boot level saveenv command doesn't work.
2) MAC address reading from ethernet EEPROM is not supported.


5. Tool Chain
-------------
The toolchain used to build the code can be obtained from CodeSourcery at the
following URL:
	http://www.codesourcery.com/sgpp/lite/arm/portal/release858

The tool chain version is Sourcery G++ Lite 2009q1-203 for ARM GNU/Linux.

The tool chain requires glibc 2.3.0 or higher to compile the source code on
the host machine.


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