Update: uMon is now booting from SD

Chris Johns chrisj at rtems.org
Sun Jul 5 22:46:28 UTC 2015

On 5/07/2015 4:19 am, Ed Sutter wrote:
> Ok, I managed to get it to boot using only Linux for formatting the card.
> It wasn't working for me until I just read your email and realized I did
> not mark
> the partition active.  After doing that it booted!
> So here are the steps I walked through
> (extracted from: http://forum.xda-developers.com/showthread.php?t=502095) :
> 1. Verify the partition that the SD card installs as:
>      - cat /proc/paritions (without the uSD)
>      - Insert uSD card
>      - cat /proc/paritions (note the difference)
> Using /dev/sdc as our partition:
> 2. sudo fdisk /dev/sdc
>     - delete all paritions with 'd' command (d1/d2/d3/d4) as needed
>     - use 'n' command to create partition 1
>     - use 't' command to relabel partition 1 to 'c'
>     - use 'a' command to make the parition active
>     - use 'p' to show something like:
>    Device Boot      Start         End      Blocks   Id  System
> /dev/sdc1   *        2048     3932159     1965056    c  W95 FAT32 (LBA)
>      - use 'w' to write to the card
> 3. Run sudo mkfs.vfat /dev/sdc1
> 4. Mount /dev/sdc1 as /media/boot (or whatever)
> 5. Copy MLO to /media/boot
> 6. Run sync; unmount /media/boot
> 7. Put card in BBB, reset with boot button depressed.

A simple request to place in the doco early is to create a root
partition only as large as you need and not use whole disk size in the
root partition. Users should be encouraged to add other partitions they
can mount as read/write to store a kernel and/or user data.


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