Hi Abraham,
Thank you very much for your detailed reply! But I think I can rule out the three possible problems you mentioned. 1. The cross compiler should be fine. Because I use it all the time to compile kernel for pandaboard and it has never been a problem 2. I'm doing exactly what you suggested, i.e. the SD card is partitioned by a pre-built image. 3. The serial cable is fine because the pre-built image was working properly with the serial cable. Only after I update the u-boot comes the no-output problem. Could you think of any other possible problem? I suspect maybe I need to modify other files (uEnv.txt, boot.scr) in the /boot partition? These files came along with the pre-built image. Thanks again.
On Fri, Nov 22, 2013 at 3:17 AM, Abraham V. abraham.varricatt@vvdntech.com wrote:
My company is designing a custom board that can be thought of as a derivative of the pandaboard. I believe we have Rev B1 with us in the office.
Considering that you are not getting any debug messages on your serial console, I suspect one of the following;
- your cross-compiler might have issues
- you haven't partitioned the SD card properly
- your serial cable might be damaged.
Just short the TX and RX lines of your serial cable to test the last point. If you can see echo messages, then good, at least the cable is working.
Next worry about the partitions - to boot from SD card, the omap4 on the pandaboard expects it in a certain format. Try using pre-build binaries. For example;
http://www.omappedia.com/wiki/Android_Panda_Pre_Built http://omappedia.org/wiki/Ubuntu_Pre-built_Binaries_Guide
They have instructions on how to format your SD card. Assuming they work, then good! Last point is to check your cross-compiler. Just replace the existing MLO and u-boot.bin (or u-boot.img; it depends on what version you have) on the SD card with your compiled ones and you'll be in a good position to narrow down bugs.
All the best, Abraham V.
On Fri, Nov 22, 2013 at 11:41 AM, Chao Xu caesarxuchao@gmail.com wrote:
Hi,
I'm trying to compile the latest u-boot for my Pandaboard Rev A2. The SD card was originally loaded with a working version of 12.04 linaro-unbunt-developer image. Early printk is enabled in the original image.
I followed this guide (http://elinux.org/Panda_How_to_MLO_%26_u-boot) and here is what I did:
- export ARCH=arm
- export CROSS_COMPILE=arm-linux-gnueabi-
- make omap4_panda_config
4.make 5. cp MLO u-boot.img /SDCARD/boot/
But when switching on my Panda, there is no output from the serial port. And the heartbeat LED is always off. (When every thing works, it is on when booting, and blinks after booting finished).
I don't have any former experience with u-boot. So please let me know if there is any more info I should provide.
Any help would be much appreciated! Thank you!
-- Regards, Chao Xu _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot