Create Account
Search
You are here: TDG Forum  >>  Freescale / NXP SOMs and Development Kits  >>  i.MX31 LITEKIT Development Kit  >>   More information on LoLo please...

Technical Discussion Group Forum

This forum is provided for user discussion. While Beacon EmbeddedWorks support staff and engineers participate, Beacon EmbeddedWorks does not guarantee the accuracy of all information within in the Technical Discussion Group (TDG).

The "Articles" forums provide brief Articles written by Beacon EmbeddedWorks engineers that address the most frequently asked technical questions.

To receive email notifications when updates are posted for a Beacon EmbeddedWorks product download, please subscribe to the TDG Forum of interest.

TDG Forum

PrevPrev Go to previous topic
NextNext Go to next topic
Last Post 26 Aug 2007 10:28 PM by  OradFarez
More information on LoLo please...
 3 Replies
Sort:
You are not authorized to post a reply.
Author Messages
OradFarez
New Member
New Member
Posts:


--
26 Aug 2007 05:00 PM
    Hello. I have designed my own baseboard which will be incompatible with the baseboard expected by the LoLo software. For now, I believe it is okay until I start using different features (second SD card slot instead of CF, different GPIO usage, etc...). Eventually I want to overwrite LoLo in NOR flash with Redboot since it is open source and I can make any changes I want.

    I have modified and built my own version of Redboot based on the one in the ltib freescale linux package, but I haven't been able to test it yet.

    I tried grounding the connections (resistor pads) for boot mode selection that select "bootloader" on power up (which is safe to do since the lines have pullup resistors to 1.8V. Then I tried using the HAB Toolkit 2.0 but it doesn't communicate with the processor. I know the DRAM is a different type but it seems to me that the registers would be loaded with the same values. If not, that is my first request(1).

    Second, I am trying to understand how LoLo works. Is it like a shell that only lets me run applications in a thread or can I execute code directly? The "exec" function seems to do that, but the board just reboots when I try it. I may need to modify RAM/ROM vectors for building redboot, but I would like to know more about memory mapping set up by LoLo (2).

    So here are the two big questions I have:
    1. What values does LoLo load into the registers of the i.MX31 processor that pertain to DRAM configuration?
    2. What does the memory map look like after LoLo gets a hold of it (physical/virtual)? What would be the best way for me to run an OS from LoLo that isn't Linux?


    A couple other questions I have for all users are:
    - Has anyone else tried this (redboot)?
    - Anyone notice that the processor and ethernet chip get slightly warm when powered on? It's not hot to the touch, but if you use a more sensitive part of your hand (side of finger) I notice a little bit of warmth in these two chips. Is it just me? Perhaps due to my own baseboard but it would be great if someone could test theirs for me.

    Thank you!
    kurtl@logicpd.com
    New Member
    New Member
    Posts:


    --
    26 Aug 2007 09:32 PM
    OradFarez,

    1) Once lolo has booted, you can use the "x" command to read any MX31 register values. So you can read back how we setup the DRAM as well as any MX31 register.
    2) The Lolo User's Manual Addendum list the memory map and how Lolo uses it.

    http://www.logicpd.com/do...31_LoLo_Addendum.pdf

    - Regarding your comment about temp, this has been brought up by our applications group. Development group has checked into it as well. At the time there was no unexpected additional power being drawn from either the MX31 or the LAN9117. It is important to keep in mind the LAN9117 draws hundreds of milliamps when powered until it is put into a sleep state. Also there are no MX31 power management features implemented in Lolo. If you boot an OS that properly scales the core voltage and CPU clock rate you should see a temp reduction.
    kurtl@logicpd.com
    New Member
    New Member
    Posts:


    --
    26 Aug 2007 09:33 PM
    OradFarez,

    1) Once lolo has booted, you can use the "x" command to read any MX31 register values. So you can read back how we setup the DRAM as well as any MX31 register.
    2) The Lolo User's Manual Addendum list the memory map and how Lolo uses it.

    http://www.logicpd.com/do...31_LoLo_Addendum.pdf

    - Regarding your comment about temp, this has been brought up by our applications group. Development group has checked into it as well. At the time there was no unexpected additional power being drawn from either the MX31 or the LAN9117. It is important to keep in mind the LAN9117 draws hundreds of milliamps when powered until it is put into a sleep state. Also there are no MX31 power management features implemented in Lolo. If you boot an OS that properly scales the core voltage and CPU clock rate you should see a temp reduction.
    OradFarez
    New Member
    New Member
    Posts:


    --
    26 Aug 2007 10:28 PM
    Hi Kurt. Thank you for this information. This is actually good to know. With LoLo running and the circuitry on my baseboard powered down (ie. only Lite card running), I am seeing 450mA of draw from a regulated 3.3V supply. I thought that was quite excessive but if you say the LAN9117 draws at least half of that, it certainly makes sense. With the reset to the i.MX31 active, I still see 150mA which is still a lot but could be the network chip and/or PMIC not gating supplies.
    You are not authorized to post a reply.

    Forums Freescale / NXP SOMs and Development Kits i.MX31 LITEKIT Development Kit