Towards an ARM system-building script

[Ganbold Tsagaankhuu]

On Tue, Oct 9, 2012 at 12:42 PM, Tim Kientzle <tim at kientzle.com> wrote:
>
> On Oct 8, 2012, at 9:07 PM, Ganbold Tsagaankhuu wrote:
>
>> On Mon, Sep 24, 2012 at 2:55 AM, Tim Kientzle <tim at kientzle.com> wrote:
>>> On Sep 4, 2012, at 9:52 PM, Tim Kientzle wrote:
>>>> On Sep 4, 2012, at 9:33 PM, Dave Cheney wrote:
>>>>
>>>>> Sorry to butt in on this discussion, but how feasible would it be to adapt this build script to the pandaboard. I understand there may be a config in svn similar to the beaglebone which may be applicable.
>
>>> I've made significant progress and would
>>> appreciate any feedback:
>>>
>>>   github.com/kientzle/freebsd-beaglebone
>>>
>>> * PandaBoard:  I have a completely untested
>>>    sketch.  Someone with a PandaBoard will need
>>>    to work through the U-Boot configuration to make
>>>    this work.
>>
>> I tried your script on PandaBoard ES.
>> Basically it works with some modifications/considerations:
>
> Wonderful!  Thanks for trying it!
>
> Please send me any patches you used; I'll try
> to incorporate them.
>
>> 1. PANDABOARD kernel config should be modified to use mmcsd card as root.
>
> Would anyone object to adding this line to FreeBSD SVN?
>
> # Boot device is 2nd slice on MMC/SD card
> options         ROOTDEVNAME=\"ufs:mmcsd0s2\"
>
>
>> 2. u-boot build complains about the board was configured to support THUMB mode
>
> Hmmm…  Not sure I understand this.
>
>> 3. Maybe there is need some more patches to have correct u-boot.bin,
>> since it looks for uImage for instance
>
> There will certainly need to be some U-Boot patches.
>
> Perhaps Oleksandr can point us to the source he
> used for that u-boot.bin?  If so, I can help fill in
> the options so it can correctly chain ubldr.
>
>> 4. I didn't dig into ubldr/u-boot much, instead modified uEnv.txt to
>> load kernel.bin from first partition which is FAT. I tried 8MB of FAT.


Progress, seems like ubldr is working after patching u-boot.
Here are the patches, uEnv.txt etc:

http://people.freebsd.org/~ganbold/pandaboard/

MLO is used from http://people.freebsd.org/~gonzo/pandaboard/

Ganbold



>> 5. I used MLO, u-boot.bin from http://people.freebsd.org/~gonzo/pandaboard/
>>
>> So how does ubldr work? Can it load kernel.bin from second partition
>> in case of PandaBoard?
>
> Yes, it can.  At heart, ubldr is the same as the FreeBSD
> loader(8) that's used for i386/amd64 booting.  In particular,
> it can load the kernel from UFS.
>
> The main difference between ubldr and loader(8)
> is in how they access hardware:  loader(8) uses
> the PC BIOS and ubldr talks to U-Boot to do low-level
> device access.
>
> I think ubldr makes a lot of sense for BeagleBone and
> probably PandaBoard.  I'm not sure it makes sense
> for Raspberry Pi, though that's a different discussion.
>
> But ubldr requires that U-Boot be built with a few
> non-standard options, so again we'll certainly have
> to patch U-Boot to enable those options.
>
>
> Tim
>