Is the linux-2.6.25.4 compatible with freescale lite5200b?

[Mike Timmons]

Henry,

You are closer than you think with the ARCH=powerpc. You need to load
one more binary file into ram and specify one more address for bootm.
You need to load the device tree blob (DENX addresses this at
http://www.denx.de/wiki/view/DULG/LinuxFDTBlob). Thanks again DENX...

 

Following your ARCH=powerpc build you should see a NEW file in your
build output: rootfs/boot/lite5200b.dtb

 

Simply tftp that file to a RAM location on your target that WILL NOT
overlap the kernel image (for obvious reasons:-))

 

Then, alter your bootm command with a SECOND address indicating where
this BLOB was placed when it was tftp'd into your RAM. In my case, I
unpack (tftp) my kernel to 0x200000 and I tftp my dtb file to 400000 so
my bootm command from the u-boot prompt looks like the following. Yes,
you need that little dash there (If your U-boot doesn't like this
command then you probably have an old U-boot version and you will need
to upgrade your U-boot. I'm using U-boot 1.3.1 and it works for me)  

 

-> bootm 200000 - 400000

 

Rather than give you the dts file (it is the device tree that gets
"compiled" to create the dtb file when you build the kernel), let me
simply tell you one thing you need to change:

 

1)       edit arch/powerpc/boot/dts/lite5200b.dts

a.       change line 45 to:        reg = <00000000 8000000>   // change
to 128M from 256M.

 

Do these two things and I think you will happily boot your 2.6.25 kernel
as ARCH=powerpc.

 

Once you are this far you will need to get familiar with the
lite5200b.dts "device tree" if you are porting this to a custom board
and/or adding HW or wanting to use external IRQs. Let's save for later.

 

On the subject of your wireless card, you can look for driver or write
your own PCI driver. Now that you are running the latest kernel (2.6.25)
I recommend you study the following books:

 

BOOK

Essential Linux Device Drivers <http://safari.oreilly.com/9780132396554>


By 

Sreekrishnan Venkateswaran
<http://www.informit.com/authors/author_bio.aspx?ISBN=9780132396554> 

 

BOOK

Linux Device Drivers, 3rd Edition <http://safari.oreilly.com/0596005903>


By 

Jonathan Corbet
<http://www.oreillynet.com/cs/catalog/view/au/592?x-t=book.view> ; Greg
Kroah-Hartman
<http://www.oreillynet.com/cs/catalog/view/au/2077?x-t=book.view> ;
Alessandro Rubini
<http://www.oreillynet.com/cs/catalog/view/au/461?x-t=book.view> 

 

A $20 per-month subscription to safari.oreilly.com will get you access
to these and MANY MORE titles (you might even be able to try it for
free).

 

 

-Mike

 

________________________________

From: hong chen [mailto:ghenrychen at gmail.com] 
Sent: Friday, June 06, 2008 1:46 AM
To: Mike Timmons
Subject: Re: Is the linux-2.6.25.4 compatible with freescale lite5200b?

 

Hi, Mike. I greatly appreciate your guidance. I am a green hand at
embedded linux.

 

I clarify that I used ARCH=ppc. And I indeed used the config file in
/arch/ppc/configs/. Furthermore, I ought to have successfully NFS
mounted my rootfs, considering that I succeeded in running the
linux-2.4.25 and NFS mounting my rootfs. (Does the different kernel
influence the NFS rootfs?)

 

Today, I have tested ARCH=powerpc, just to obtaind the following result:

 

=> bootm fe000000
## Booting image at fe000000 ...
   Image Name:   Linux-2.6.26-rc4-01178-g1f01800-
   Image Type:   PowerPC Linux Kernel Image (gzip compressed)
   Data Size:    1339544 Bytes =  1.3 MB
   Load Address: 00000000
   Entry Point:  00000000
   Uncompressing Kernel Image ... OK

<------The U-boot stopped here. I seems to be worse than ever.

 

Then I have another question: how to set the $CROSS_COMPILE? ppc_6xx- or
powerpc-linux-?

I set CROSS_COMPILE=/opt/eldk/usr/bin/ppc_6xx- in the top Makefile. My
toolchain is ELDK 4.2.

 

Mike, would you please send me lite5200b.dts and other patch about
lite5200b? I want to compare and do some patch. I think they are useful
for me. I want to make some wireless application based on this board
next. I have an 802.11n wireless card. And I want to plug it into PCI
port.

 

-Henry

 

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