Linux Kernel Source Tree and Patches

I am assuming this is for one of our DaVinci products and you are referring to the Linux kernel tree.  If so, ...

 1) If you are using DVSDK kernel, you can get the latest software from our software update site which is accesible to all registered EVM users.

    http://focus.ti.com/dsp/docs/dspsplash.tsp?contentId=33169&DCMP=dm6446dvevm&HQS=EVM+OT+dvevmupdates

2) If you bought one of the DVSPB bundles, and are using the kernel from MontaVista Zone, then you can get the patches from MV Zone.

In the context of Davinci devices you would get the latest releases from www.ti.com/davinciregistration. After registering the board at that site you can follow through a link to the actual updates site, this applies to any of the Davinci devices (DM6446, DM355, DM6467, DM6437, DM648).

 Edit: looks like Juan beat me by a few seconds on this one, in any case I hope this answers your question, sorry for the double post :)

Bernie's link and my link lead to the same website; his is much nicer of course, I just like to cut and paste instead of typing :)

I have two follow up questions:

 1) I've been told that the MontaVista and TI patch lines are incompatible and that TI tends to be "more current."  What differences do you know of, if any between the latest patched trees from MontaVista and TI and is one "better'?

 2) We've only bought one EVM and it is registered to another engineer.  Rather than bug him about checking updates or getting his my.TI password, is there some way I can gain access to TI's updates (without buying another EVM)?

 Thanks.

1. They can be incompatible, but not necessarily everything is. In general as I understand the differences will be that the TI updates will be more specific to driver fixes and enhancements whereas the Monta Vista updates will be toward the general kernel. Often the benefits users gain from the driver improvements is considered most valuable so we tend to see users updating based on the EVM updates site DVSDK releases.

2. Unfortunately at this time the only way to get access to the updates site is to have a my.ti account registered with a EVM serial number, so you could really only do as you describe by bugging him for updates, sharing his password, or purchasing another EVM.

 Hi,

 Please read through the updates on the link :- 

http://tiexpressdsp.com/wiki/index.php?title=PSP_Introduction_and_Product_FAQ

 It should answer all your questions. Questions 3-7 and questions 9-10.  PSP poduct downloads are available at the PSP update advisor site at :-

https://www-a.ti.com/downloads/sds_support/targetcontent/psp/index.html 

If you need further information do let me know

thanks 

regards

sathya 

I like to add a few comments with regards to patches.

TI writes DaVinci specific software drivers; as bug-fixes or new features are added to these drivers, we

1) Roll these changes to our next DVSDK software release (have also been made available in the form of TI-patches, but noticed this directory was missing from latest DVSDK release 1.30.00.40). 

2) Submit patches for changes to MontaVista, which they merge into their kernel.  Please note that MontaVista provides DaVinci specific and non-Davinci specific kernel updates (often to the same driver) and even provides updates that are not kernel related (e.g. DevRocket...), this is part of the reason customers pay the extra $$ for.  This also means that you should avoid mixing TI-patches with MV patches as this can become very hard to maintain or break things.

Therefore, when new DVSDK is released, it will likely have newer DaVinci-specific driver updates (than MV Zone) for a short time; eventually, MV Zone will catch up.  However, DVSDK releases do not occur very often, hence there is only a small window when this should be true.

Let me first say that the only reason I'm going through all this trouble is because I want to be sure my kernel includes the resizer driver for Davinci.  I had a version of the kernel tree installed on a different machine when I was working with the EVM but I can't remember what version of the PSP/LSP I got it from.

 I have downloaded the 1.30.00.82 release of the DVSDK from the PSP update site; specifically the 'LSP 1.30' GA link on this page: https://www-a.ti.com/downloads/sds_support/targetcontent/psp/mv_lsp_1_30/index.html

After extracting it I ran the mvl_4_0_1_demo_lsp_setuplinux_1_30_00_082.bin to extract the kernel source tree.  Upon examination, it does not include the davinci_resizer.c file in media/video/davinci like I expected, nor does it contain a patch file for the resizer (MontaVista number 1641 according to the Wiki page linked to a couple of posts ago).  Juan mentioned that he didn't see the directory (I assume patch directory) included in the 1.30.0.82 release.  Assuming I downloaded and extracted the right files (the "demo" part of that .bin file leads me to believe I may have gotten the wrong one), I'm sure that since I'm missing the resizer patch, I'm missing a bunch of other patches too.  MontaVista seems only to offer individual patches as opposed to a big pack.  Am I stuck figuring out which patches I need and downloading them individually from MV? Is the 1.20 release of the DVSDK properly packaged and if so, should I use that instead?  Is there an updated archive for the 1.30 release that includes the directory Juan mentioned?

SJackson,

My recommendation would be to use official DVSDK releases available thru our software update site; when you start downloading individual components of the DVSDK (such as a new LSP version), you can run into problems/frusturations.   See following post: https://community.ti.com/forums/t/75.aspx

The latest DVSDK (version 1.30.00.40) includes resizer driver (no need to add patches).   Also, the 'patches' folder I suggested was missing from the latest DVSDK release served very little purpose as patches are already included in the kernel; however, those are available via update advisor if you really need them.

Edit: Also, resizer driver location under Linux kernel is .../drivers/char (also present in DVSDK 1.20)

Juan:

Thanks I found the driver files in the source tree.  I was confused because I didn't see any kernel options asking whether or not I wanted it to be built into my kernel image.  I'm assuming this means that it is now built into the kernel by default.

Resizer driver can be included/excluded from the kernel via the following menuconfig build option

Device Drivers -> Character Devices -> DaVinci Resizer Driver

This is documented on the Resizer Driver User Guide (SRPUFF0.pdf), included with DVSDK 1.30 or newer.

I must have done something wrong when unpacking/installing the DVSDK 1.3 then.  I'll go back and give it another shot.

You should be able to see that option with DVSDK 1.20 as well.

I figured out what I was doing that caused the Resizer driver to be unavailable.  I had disabled the TI DaVinci EVM option under System Type and Featues -> TI DaVinci Implementations since it says it's for use on EVM boards, whereas I'm using a custom board.  Enabling this caused the Resizer driver, among other things, to become available.

 Do you know what specifically about this option the Resizer depends on?  I ask because I anticipate having to develop some custom kernel startup code and while I intend on using the EVM board source files as a starting point, I want to be sure not to disturb critical code that the resizer depends on.

The kernel build tree is made up of a hierarchy of build scripts which I will not attempt to describe here; but one aspect of this hierarchy is various Kconfig files that appear throughout the source tree, such as the one found in  .../drivers/char

If you look at ../driver/char/Kconfig file, you will see that resizer drivers depends on MACH_DAVINCI_EVM; as you can guess, this gets set by the option you mentioned in your post (see .../arch/arm/mach-davinci/Kconfig file).  By typing

 > make ARCH=arm CROSS_COMPILE=arm_v5t_le- davinci_dm644x_defconfig

as instructed by the Getting Started Guide, all these options should be appropriately set for you.

Please note that if you are going to be dealing with making your own board configuration, you should learn a bit more about the kernel build process.  I briefly touched on a few places to look.

Hii,

I am a newbie working on OMAP 2430 for a video application. I have tried two kernel versions of 2.6.14 and 2.6.17 to boot with OMAP 2430 board but failed. I have used another kernel 2.6.26 which worked fine. Now i need to use the DSP bridge on OMAP Board.

Can any one help me on how to do this ???? I  tried to enable the DSPgateway support while compiling for OMAP 2430. It compiles with no errors and creates an image . I could not see any dsp brideg driver loaded on the board..

Any kind of help is highly appreciated.

Thanks & Regards

Ramalk.