Is the linux-2.6.25.4 compatible with freescale lite5200b?

[Mike Timmons]

Hi Henry. I recently migrated to ARCH=powerpc on 2.6.24 from ARCH=ppc on
2.6.16 (having obtained a distribution from the ltib project).

 

The ppc architecture is nearing end-of-life as far as development goes,
so I recommend jumping to powerpc now. In mey recent experience I
encountered better driver support, and I generally noticed that future
patching/development would support ARCH=powerpc. I think the old ppc
implied embedded (or non-mac) architectures, while the powerpc was
intended for mac desktops. I might be wrong, but it looks like the two
have merged.

 

This architecture issue doesn't speak directly to your question, but if
you could get 2.6.25 working with ARCH=powerpc on your lite5200b then
you and I would be working with basically the same set-up and I could
help you better. For now, here are a few questions:

 

1)      Have you successfully NFS mounted your rootfs and not woried
about the RAMdisk at this point?

2)      Maybe you are using ARCH=powerpc, but your comment in
/arch/ppc/configs/ has me confused. Did you mean in
/arch/powerpc/configs/ ?

 

Please clarify if you are using ARCH=powerpc and I think I can be of
more assistance. For example, on my 2.6.24 kernel I needed to...

1)      Halve the memory sive specified in lite5200b.dts. It specified
twice as much memory as is actually on my lite5200b, causing a strange,
long delay at boot time as page initialization attempted to operate on a
bunch of non-existent memory, near as I can tell. The symptom was around
30-45 seconds of delay between U-boot boot and any console output.
Weird, but I figured it had something to do with RAM initialization only
after getting my BDI2000 JTAG debugger going and breaking to see that
the kernel appears stuck on something related to initializing the RAM.
This drove me to discover the size spec is wrong in the dts file.

2)      If you need edge-sensitive interrupts you'll need a set
interrupt type callback. Mpc52xx_pic.c is missing this callback. Check
another powerpc architecture for set_interrupt_type. I would upload a
patch but it turns out I am fine with level-sensitive only so I didn't
go through the trouble of formalizing a fix for this.

3)      SPI driver for SPI peripheral (not PSC): this is missing but
there is a patch for it. Tell me if you need it and I'll direct you).

4)      IN GENERAL, THE DEVICE TREE CONCEPT IS COOL, BUT IT HAS A
LEARNING CURVE. I can help you. For example, just requesting an external
IRQ requires creating a "device" node so that you can associate a
specific IRQ number with said device for easy access from your module
driver code at run time. Basically, ALL register access is done by
run-time parsing of the device tree information, NOT by simply direct
register access, given a bunch of defined address constants in some
header file.

 

Sorry if none of this helps, but I just recently clawed my way up the
learning curve so some of the wounds are fresh. Hopefully I can provide
a bit of guidance on the easy concepts.

 

-Mike

 

 

________________________________

From: linuxppc-embedded-bounces+mike_timmons=trimble.com at ozlabs.org
[mailto:linuxppc-embedded-bounces+mike_timmons=trimble.com at ozlabs.org]
On Behalf Of Henry Chen
Sent: Tuesday, June 03, 2008 9:55 PM
To: linuxppc-embedded at ozlabs.org
Subject: Is the linux-2.6.25.4 compatible with freescale lite5200b?

 

Hi, all expert!

 

Thank you for your patience.

 

I want to use Linux as the OS of freescale lite5200b develop board. Then
I have tried two version of kernel, 2.6.25.4 and 2.4.25.

We succeed in 2.4.25, failed in 2.6.25.4. We use the default config file
for the board, lite5200_defconfig, which would be found both in
/arch/ppc/configs/. And we use the same ramdisk. The following info is
about the error of 2.6.15.4.

 

=> bootm fe000000 fe200000

## Booting image at fe000000 ...

   Image Name:   Linux-2.6.25

   Image Type:   PowerPC Linux Kernel Image (gzip compressed)

   Data Size:    802989 Bytes = 784.2 kB

   Load Address: 00000000

   Entry Point:  00000000

   Uncompressing Kernel Image ... OK

## Loading RAMDisk Image at fe200000 ...

   Image Name:   rootfs in flash

   Image Type:   PowerPC Linux RAMDisk Image (gzip compressed)

   Data Size:    5055519 Bytes =  4.8 MB

   Load Address: fe5a0000

   Entry Point:  fe5a0000

   Loading Ramdisk to 0fa7c000, end 0ff4e41f ... OK

id mach(): done

MMU:enter

MMU:hw init

MMU:mapin

MMU:setio

MMU:exit

setup_arch: enter

setup_arch: bootmem

arch: exit

 

Would you please help us to solve it and explain the cause?

 

Best regards!

 

Sincerely yours,

Henry

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