[U-Boot] Custom MPC8548 boot using FDT problem (more info)

[Pieter]

Jerry Van Baren wrote:
> Pieter wrote:
>> Hi all
>>
>> I have been working on booting our custom MPC8548 board using a FDT.
>> The board boots up to the point where "controll is passed to Linux"
>> and then nothing happens. I have plased the final part of the console
>> output at the bottom of this message.
>>
>> Does anyone have an idea about what is going wrong?
>> Is the error in my u-boot, device tree blob or linux kernel side?
>
> Probably.  :-/
>> thanks pieter
>>
>>     WARNING: adjusting available memory to 10000000
>>     ## Booting kernel from Legacy Image at 00200000 ...
> Try a higher address, say 00400000?
>>        Image Name:   Linux-2.6.27
>>        Image Type:   PowerPC Linux Kernel Image (gzip compressed)
>>        Data Size:    1194002 Bytes =  1.1 MB
>>        Load Address: 00000000
>>        Entry Point:  00000000
>>        Verifying Checksum ... OK
>>        kernel data at 0x00200040, len = 0x00123812 (1194002)
>>     ## Flattened Device Tree blob at 00800000
>>        Booting using the fdt blob at 0x800000
>>        of_flat_tree at 0x00800000 size 0x000037bc
>>        Uncompressing Kernel Image ... OK
>>        kernel loaded at 0x00000000, end = 0x00294a90
>>     ## device tree at 0x00800000 ... 0x008037BB (len=26556=0x67BC)
>>     ## Transferring control to Linux (at address 00000000) ...
>>        Booting using OF flat tree...
> Where did you get your FDT source from?
> Did you modify it?
> Does your FDT blob get properly fixed up by your u-boot?
>
> It is difficult (and not very profitable) to try to make a new linux
> kernel run with an old u-boot version because both linux and u-boot
> fdt handling matured considerably over the last year.  The (kernel)
> FDT blob sources have matured a huge amount over the last year.
>
> Good luck,
> gvb
I should have added more specific information - i apologize.
The board worked on my old plarform which consisted of U-Boot 1.2 
booting Linux 2.6.24  not using a FDT. ( the ppc architecture).My
current effort is porting to U-Boot 2008.10 and booting Linux 2.6.27.
This prompted the move to the powerpc architecture and requirement to
use a FDT.

The Designers of the board I have did not support FDT, thus I created a
FDT source for my board based on the sbc8548 board (included in U-boot)
and using the  "Booting the Linux/ppc kernel without Open Firmware"
document supplied with Lnux 2.6.27. I am uncertain about assigning
interrupts to the variouse nodes.

I compiled the blob using dtc Version: 1.1.0:
dtc -b 0 -V 17 -p 0x2000 -I dts -R 8 -O dtb -f
arch/powerpc/boot/dts/equus.dts > SDH0/tftp/equus.dtb

My FDT blob is minimal, containg the CPU node, Memory node, SOC node
and  Localbus. U-boot seems happy with the blob and fill in the
appropriate field in the CPU node (bus / cpu clocks) and Ethernet MAC
addresses

I moved both the uImage and the FDTblob load addresses higher,
0x01000000 and  0x02000000 respectively.
but the boot stil hangs after  " ## Transferring control to Linux (at
address 00000000) ... Booting using OF flat tree... "