Nishanth' tech rambles

Grr my first post of this year and I plan to start "I confess: I am a paranoid". what the heck, lets go with it: I confess, I am a paranoid. I carry around my N900 all the time and thanks to my job, I end up in different continents at times. with my primary SIM connection, international data network tends to around 15$/MB which I don't really feel like paying, so I either choose a local SIM (If I am around for that long that deserves it) OR more likely to use WLAN in the hotel or guest network I am allowed on. I don't like wlan network in general other than the one I personally setup. and hence dont like the thought that my phone's network services are open for all on wlan0 device :(. This triggered my search for something quick and simple firewall. I think of it more or less as a basic password I'd setup on my laptop of a phone unlock code or lock my car when I step out of it - it can be counteracted, but what the heck, some one has to see it worthwhile the e...

Thanks to rkw, heard of this: http://linux-c6x.org/wiki/index.php/Main_Page it is based on 2.6.34 - pretty much closer to .36-rc5 ;) and needs some more work I guess.. mostly, it would be a great thing to get this running on beagleboard ! I cant think why not.. ;)

it is exciting news and there is no reason for me to do the good old style of a post.. so here it goes: Jason's state of the beagle address (somehow sounds similar to this - no offense intended ofcourse) had the following highlights (or my view how as an engineer I'd have paraphrased): Beagleboard rocks . (and we have awards to prove it too ;) ).. We kinda got screwed by beagle's success initially, but now I think things are better now.. beagleboard is getting an engine change soon - blistering speeds ahead dudes.. 720meg beagles.. get those apps rockin.. Annnndddd..... Yeeeehaaaawww.. beagleboard XM !!!!!! DM3730(dudes in l-o know the diff with OMAP3630).. wow.. more juice under the hood man... mama mia!!! camera, 4 port ehci, usb2ethernet the good ol' lcd and expansion connectors, everything we all cribbed and wanted our fav beagle to have, is there now! Go Go Gerald ;) for those newbies.. go do the training and get rockin faster..(android/angstrom.. whatever ...

So omapzoom folks have a tutorial hour now, some really cool topics get caught up here.. this week: · Android on OMAP Overview and Resources · DSP Bridge Overview · OpenEmbedded Overview it is a webex (works on most OSes including a linux PC) + teleconf -> large number of access numbers from around the world more information here . the OMAP tutorial hour (including the previous presentations - which by the way explains kernel process from TI) are available here .

Googling around, I found this beautiful article that gives excellent explanation of how Adaptive Voltage behaves in the system. by the way, this is going to be part of my rewrite of smart reflex driver to make the voltage infrastructure a lot more cleaner and easy to use. General flow I am thinking is as follows(will change ofcourse): voltage driver |------------> No SR PMICs implementation thru regulator framework perhaps. \-------> Smart reflex driver |----> PMIC interface (for class 0 devices) |-----------------------------------\ \-----> Voltage processor driver -> Voltage controller driver Ofcourse things might change as I move on with the implementation (I need to think a little more on this), but once I am done, you should be able to see it here

After a long while of staying off linux-omap, been watching it rather closely recently.. here are some interesting stuff I saw this month: Power Management: Operating points and general PM strategy for handling for various silicons here Silicon Feature support for OMAP3 here New silicon support: OMAP35xx and 36xx support being introduced. Discussion on memory and cache issue here ETM, ETM support here few new PMIC - 6030 and 5031 hints of wl1251 support getting upstream IO_ADDRESS is dead use io_remap like the rest of the world spring cleaning of omap850/730 series and of course a bunch of stuff I have missed posting here such as move to 2.6.32-rc4 by Tony and Kevin, both pushing out patches to mainline etc.....

Looking through the beagleboard facebook group , Saw two interesting points: Flash Lite 3.1 evaluation version for Beagleboard For all the Beagleboard fans out there, we’ve created an evaluation version of Flash Lite 3. This is a fully functional version of Flash Lite that times out in 3 minutes. It is built on Angstrom Linux distribution and requires X. Please email me if you are looking for more information or are interested in having one. I should mention that OMAP 3530 (ARM Cortex A8) is a powerful CPU and seems to handle graphics as well as video very well." How to build Valgrind for Beagleboard 1) Get Valgrind source code from SVN using revision 9648 and 1888 for VEX svn co -r 9648 svn://svn.valgrind.org/val grind/trunk cd VEX svn update -r 1888 2) Download the patch here http://bugsfiles.kde.org/a ttachment.cgi?id=32348 3) Apply the patch into the source code cd valgrind patch -p1 4) Run autogen.sh to run autotools 5) Configure the source code ./configure --host=arm-angst...

Finally.... here it is!!! patches for u-boot to be send straight to u-boot mailing list .

Wow.. a blast of new sites for omapzoom.. And then I see this on the new omapzoom google groups !!! * MPEG4 Video Dec * H263 Video Dec * JPEG Dec * JPEG Enc * AAC Dec https://gforge.ti.com/gf/project/openmax/frs/?action=index And you also now have a wiki for omap

beagleboard.org has already a pretty active community in linkedin.. the following news items were picked up from the groups' Cloumnist update ( ;) thank you.. great job by the way): GL to GLES converter announced http://code.google.com/p/gl-wes-v2/ Good for Pandora, the OMAP3 based gaming platform Recommend Link: http://code.google.com/p/gl-wes-v2/ White paper: Power-management techniques for OMAP35x From: E-R: RSS Columnists | May 26, 2009 TI's OMAP3 application processors address the need for low power without sacrificing performance. Static power management idles a system in a power-efficient state until processing is required, while active power management adjusts More » White paper: Power-management techniques for OMAP35x Link: http://focus.ti.com/general/docs/gencontent.tsp?co...

yes, we have heard of openOCD, Lauterbach, yet till date, I personally have'nt been able to use CCS to debug linux.. This post gives an interesting saga for those interested Warning : it is a little lengthy post, so as of the time of posting: Summary - CCS4 has support for linux kernel aware debugging, and unfortunately there is a small glitch of support of kernels 2.6.26 and above - the ccs team is working on a fix at this point.. hopefully we will have a full soln soon.. Thanks to John in deligently following up on this..

[discussion thread here ] Few days back looking at OMAP3430 Public TRM I found the section 26.4.8.2(page 3427), it was exciting to see what possibilities lay here.. a little more digging later and few hours of coding later, figured out that by adding a certain data as a prefix to the real image, we can boot u-boot or for that matter any image straight from NAND flash into sdram.. essentially this is what x-loader does, only that OMAP3430 ROMCode already has that feature.. What exactly is Configuration Header(CH)? CH is a set of register values to the critical OMAP registers that define how the clocks, sdram controller, gpmc controller, mmc controllers are configured.. it is more like an array of register values - you fill them up with the correct values, and store the load address you would like the resultant image to load up, bingo, we have the image booting off that location.. There are few of these structures that are defined in the TRM which has a detailed description on the real...

With the recent merge of mtdparts patch for beagleboard u-boot Texas Instruments X-Loader 1.4.2 (Jan 30 2009 - 19:16:17) Loading u-boot.bin from nand U-Boot 2009.03-00325-gf75a729 (Apr 09 2009 - 13:36:05) OMAP3530-GP rev 2, CPU-OPP2 L3-165MHz OMAP3 Beagle board + LPDDR/NAND DRAM: 256 MB NAND: 256 MiB In: serial Out: serial Err: serial Board revision C Die ID #0a8600030000000004013f780600a00e OMAP3 beagleboard.org # you can now do cool things without having to remember the offsets of which partition was where.... (lets say you want to copy the kernel to nand flash) Step1: setup the partitions OMAP3 beagleboard.org # mtdparts default Step 2: erase the nand flash for kernel partition OMAP3 beagleboard.org # nand erase kernel NAND erase: device 0 offset 0x280000, size 0x400000 Erasing at 0x660000 -- 100% complete. OK Step 3: copy the kernel from RAM to the kernel partition in nand flash: OMAP3 beagleboard.org # nand write 0x80000000 kernel NAND write: device 0 offset 0x280000, si...

The following instructions are for 2.6.28 linux omap pm branch + tidspbridge Few links: * http://gitorious.org/projects/tidspbridge/repos/mainline - TIDSP Bridge codebase * http://patchwork.kernel.org/project/linux-omap/list/?q=DSP - pending patches on linux-omap mailing list * http://git.kernel.org/?p=linux/kernel/git/khilman/linux-omap-pm.git;a=summary - kevin's tree for Power management Steps: git clone git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-omap-pm.git cd linux-omap-pm git checkout -b pm-2.6.28 --track origin/pm-2.6.28 git checkout -b tidspbridge git pull git://gitorious.org/tidspbridge/mainline.git tidspbridge-pm-2.6.28 make omap_3430sdp_defconfig for powermanagement: make CONFIG_OMAP_PM_SRF=y CONFIG_MPU_BRIDGE=m or y which ever is your preference.. enable BRIDGE_DVFS as y make uImage;make modules and bingo you should have arch/arm/mach-omap2/dspbridge.ko and arch/arm/mach-omap2/dspbridge.ko if you have dspbridge as a a module ;)... insmod dspbridge.ko ...

The following check list was compiled based on a discussion here a) Did you check if the device id of the device is in TRM under supported devices? -> ROM Code should support this device if it should ever boot.. b) Did you read your CTRL_STATUS register and verify the SYSBOOT boot sequence in TRM -> is NAND in the sequence and nothing else preventing it from being hit? c) what is the status of your EMU0-1 JTAG pins are they both high or in tristate condition during OMAP boot? -> the wrong setting would prevent boot sequence from being executed d) is it on CS0? -> well OMAP boots out of CS0 e) Do you have an 8 bit or a 16 bit NAND? is your config file in x-loader, u-boot handling this correctly? -> accessing wrong width is not very helpful.. ;) f) Did you sign x-loader.bin.ift with signGP.c? Try this in x-loader directory: grep _start System.map|cut -d' ' -f1|xargs signGP x-load.bin -> x-loader loads up at the address we tell it to, few variants of x-loaders s...

Finally! After months of effort by many, mostly Dirk driving hard, we have omap3 support in: a) beagleboard b) overo c) evm d) pandora e) zoom1. This should ideally make omapzoom git based u-boo t redundant. Lets see if this happens in the upcoming days.. v2009.02 will have official support :).. Hip Hip Hooraah!!

[2013-03-06 update]: after a few years of letting things rot, I just managed to pick up my old binaries and gave it a dry run: https://github.com/nmenon/beagle-recover  has the original working binaries since the google groups link no longer work. NOTE: I HAVE NOT TRIED WITH ANY OF THE LATEST SOURCES. I do not have plans to do so in the future as well  - an quick try indicated things are broke :( [Original post] http://groups.google.com/group/beagleboard/web/beagle_recover.tar.bz2 has the recovery package ready to go for ubuntu 8.04 32bit OS: download this, run sudo ./recover_beagle.sh - as shown in the video... Steps summary: 1. first shutdown the board. 2. run 'sudo recover_beagle.sh /dev/ttyUSB0' in a terminal -> you need super user permissions(sudo permissions) to run this script. 3. Keep the pushbutton S1pressed while powering on the board -> there are two white push button switches, use the one closer to the edge of the board NOTE: if your nand is com...

for some time now, I have gone with the belief that the nand ecc imlementation such as this which I helped write good enough for nand devices, but Vimal Singh pointed me to these two articles: http://lists.infradead.org/pipermail/linux-mtd/2008-August/022611.html http://lists.infradead.org/pipermail/linux-mtd/2008-August/022613.html Essentially: If we do just old_ecc^new_ecc to detect/correct ecc errors - the logic handles the case of bit flip error at 63rd bit(as e.g.) faultily. I was completely unaware of this weakness of the algo.. thanks Vimal for pointing me here.. I have plans of setting up a bit of code to verify this (essentially hack up the current drivers by overriding the read path ;) ).. will post if I can proove(I suspect this would be the case) this is the case with gpmc..

Tony Lindgren, Linux OMAP maintainer announced that source.mvista.com linux omap copy would not be used anymore.. It has been more than three years since the discussion on hosting the kernel tree at mvista site .. Thank you mvista for hosting all our pulls to date.. from now on look here (actually it was there since 2006, though I will miss doing " linux omap git " on google).

Kinda got a few questions on how omap uboot utils works.. so here is my attempt to try and summarize what omap3 TRM says(for details TRM is the best place to go - yes, it is beautifully written ;) ): ARM is a useless unless we have some software to run on it, so OMAP has a special piece of ROM code which gets the initial control of things. Now, ROM code is capable of: a) booting off a memory device such as NOR, NAND, OneNAND, MMC etc.. kind of devices. b) booting off a peripheral such as UART, USB etc.. Before anyone asks, yep ROMCode is a software code within OMAP. And, yep, and yeah it's got all kind of drivers for devices it supports, and further yeah, it is a tiny optimized code and finally NO - you cant modify it since it is R ead O nly M emory. Now, in the world of OMAP s/w guys, (a) is called memory boot and (b) is called peripheral boot.. Now, how does ROM Code know what kind of device you have and which mode you want to boot from? This is called the SYSBOOT(again read th...