Thank you again. That's got me a little further.

I notice from looking at the sd card it uses ext3 for the boot partition, ext4 for the root file system, so the dd to the mmc must preserve that. Unfortunately the boot loader only has an ext2load and ext4load. Consulting with a colleague and Mr google, I shouldn't expect an ext3load to be available but ext2load might well load ext3 with a little bit of luck.

I duly proceeded under that assumption and got the following results:

U-Boot# setenv bootargs console=${console} root=LABEL=_/ ro rootwait
U-Boot# saveenv
Saving Environment to MMC...
Writing to MMC(1)... done
U-Boot# ext2load mmcblk 0:1 0x80300000 vmlinuz-4.0.4-301.fc22.armv7hl
mmc_send_cmd: timeout: CTO
mmc_send_cmd: timeout: CTO
5645832 bytes read in 660 ms (8.2 MiB/s)

<repeated the above because of the timeout>

U-Boot# ext2load mmcblk 0:1 0x80300000 vmlinuz-4.0.4-301.fc22.armv7hl
5645832 bytes read in 661 ms (8.1 MiB/s)
U-Boot# ext2load mmcblk 0:1 0x81600000 uInitrd-4.0.4-301.fc22.armv7hl
27397171 bytes read in 3184 ms (8.2 MiB/s)
U-Boot# ext2load mmcblk 0:1 0x89300000 hub.dtb
31710 bytes read in 14 ms (2.2 MiB/s)
U-Boot# bootz 0x80300000 0x81600000 0x89300000
## Loading init Ramdisk from Legacy Image at 81600000 ...
   Image Name:   initramfs
   Image Type:   ARM Linux RAMDisk Image (uncompressed)
   Data Size:    27397107 Bytes = 26.1 MiB
   Load Address: 00000000
   Entry Point:  00000000
## Flattened Device Tree blob at 89300000
   Booting using the fdt blob at 0x89300000
   Loading Ramdisk to 9e404000, end 9fe24bf3 ... OK
   Using Device Tree in place at 89300000, end 8930abdd

Starting kernel ...

<then it just HANGS>

A colleague who is looking into using another well-known ARM linux distro found that the dtb file used with Angstrom needed some minor modification before it could be with that distro (and would otherwise hang), so  that is an area of investigation. I guess it would be good to nail down whether I am getting problems because of the ext2/ext3 or get some clues as to where it is bombing out.

I do have access to the u-boot source.

Andrew

On 17 June 2015 at 11:42, Peter Robinson <pbrobinson@gmail.com> wrote:
Hi Andrew,

> It's using a TI AM3352 OMAP family SoC. Overall it looks like a BeagleBone
> Black, but no EEPROM on i2c, different DDR RAM (and no sd card socket).
>
> I do have a device tree. I have full access to all the bits and pieces put
> together to make this boot under Angstrom, just don't know how to re-arrange
> them to make it boot under Fedora!

So if you've copied the DT onto the boot partition (partition 1) you
should be able do something along the lines of the bits below to get
it booting. I'm making the assumption here that it's got eMMC for the
onboard flash and it's identified as mmc0, update as appropriate. You
might need to swap ext4 for ext2, obviously update the name of the
dtb.

setenv bootargs console=${console} root=LABEL=_/ ro rootwait
ext4load mmc 0:1 0x80300000 vmlinuz-4.0.4-301.fc22.armv7hl
ext4load mmc 0:1 0x81600000 uInitrd-4.0.4-301.fc22.armv7hl
ext4load mmc 0:1 0x89300000 blah-blah.dtb
bootz 0x80300000 0x81600000 0x89300000

Let me know how you get on.

Do you have access to the u-boot source?

Peter