Re: BeagleBone Black boot information

[Matt Thomas <matt%3am-software.com@localhost>]

On Jul 20, 2013, at 6:50 PM, John Klos <john%ziaspace.com@localhost> wrote:

> Hi,
> 
> Is there an MLO for the BeagleBone Black yet which can load a kernel from 
> ffs? I'm using MLO and u-boot.img from this page:
> 
> http://people.freebsd.org/~dmarion/beaglebone/creating_bootable_sd_card/

Try loading at 82000000.

> Why is the kernel compiled with:
> load addr:   0x80300000
> entry point: 0x80300000

Because the kernel size will always overflow the default loadaddr.

> yet when I try to load and boot the kernel there, it fails:
> 
> U-Boot# fatload mmc 0:1 80300000 netbsd.ub
> reading netbsd.ub
> 2998016 bytes read in 344 ms (8.3 MiB/s)
> U-Boot# bootm 80300000
> ## Booting kernel from Legacy Image at 80300000 ...
>   Image Name:   NetBSD/beagle 6.99.23
>   Image Type:   ARM NetBSD Kernel Image (uncompressed)
>   Data Size:    2997952 Bytes = 2.9 MiB
>   Load Address: 80300000
>   Entry Point:  80300000
>   Verifying Checksum ... OK
>   XIP Kernel Image ... OK
> OK
> ## Transferring control to NetBSD stage-2 loader (at address 80300000) ...
> 
> 
> When I load and run from 0x81000000, it works... So what's the relationship 
> between the NetBSD kernel's load address and entry point and u-boot's load 
> address and start address?

None.  You always need to specify a high enough load address.

> I'm trying to make sense of all of this because the GNU/Linux documentation 
> assumes the world is GNU/Linux and doesn't talk about the BeagleBone except 
> assuming that the OS is already booted, plus there is no NetBSD documentation 
> and the only mentions of NetBSD on BeagleBone Black just say it boots, not 
> how to set up a working system. I suppose a HOW-TO is in order, which I'll do 
> when I've gotten mine working.