serial boot on AM3359. MLO does not give prompt

brent Saunders

I have a design based on the Beagle Bone Black with no uSD interface. I need to boot from the serial interface. I can get the "C" prompt when I set sysboot[4:0] to 11000. However when I upload MLO from my BBB using XMODEM, I get no prompt. If I try to continue and send u-boot.img without the prompt, it hangs. What am I doing wrong? Is there a different MLO for serial boot?

over 11 years ago

0 Steve Kipisz over 11 years ago

TI__Genius 15510 points

For serial booting you do not send the MLO. Look in your u-boot/spl directory and send the u-boot-spl.bin file. Serial booting expects a flat binary file (u-boot-spl.bin) while the MLO file has a small header in front of it.

Steve K.

0 brent Saunders over 11 years ago in reply to Steve Kipisz

Prodigy 130 points

there is no u-boot/spl directory on my BBB and no u-boot-spl.bin anywhere on the drive. I cannot fine one on the Beaglebone.org site either. Any idea where I can get this?

0 Steve Kipisz over 11 years ago in reply to brent Saunders

TI__Genius 15510 points

Ok. I buld u-boot from source so I have the .bin file. What you can do is strip off the header and use the file without it. From a Linux command prompt

dd if=MLO of=u-boot-spl.bin bs=1 skip=520

Then you should be able to boot over serial the u-boot-spl.bin file you just created.

Steve K.

0 brent Saunders over 11 years ago in reply to Steve Kipisz

Prodigy 130 points

Thanks so much!!! Got it working. After loading u-boot-spl.bin with XMODEM, sent u-boot.img with YMODEM. UBOOT came right up. I will now try to boot from NFS.

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serial boot on AM3359. MLO does not give prompt