IMX257 framebuffer problem

[Stefan Koch]

Hi,

I am porting Linux 3.6.2 to a board with Freescale IMX 257 ARM-CPU.

Linux works mostly, kernel can run, and Debian can run with kernel, too.

So I can get access via UART to Debian's Linux console and install 
packages via apt-get and so on.

So the next step is to enable the graphics support.

The line "imx25_add_imx_fb(&mx25cevipro_fb_pdata);" enables this.

Linux kernel works fine when this line is uncommented, but when it is 
active kernel stops before print out the first message on serial line.

So openocd prints with general U-Boot kernel boot:
WARNING: unknown debug reason: 0xf
ThumbEE -- incomplete support
target state: halted
target halted in ThumbEE state due to debug-request, current mode: System
cpsr: 0xffffffff pc: 0xfffffff9
MMU: enabled, D-Cache: enabled, I-Cache: enabled

And if I use gdb for loading and step through the source beginning from 
add_imx_fb(...) line I will get these output from openocd:

Unable to set 32 bit software breakpoint at address 8057c7e0 - check 
that memory is read/writable
Unable to set 32 bit software breakpoint at address 8057c7e0 - check 
that memory is read/writable
breakpoint not set
> poll
background polling: on
TAP: imx25.cpu (enabled)
target state: halted
target halted in ARM state due to breakpoint, current mode: Supervisor
cpsr: 0x40000013 pc: 0x8057c7e0
MMU: enabled, D-Cache: enabled, I-Cache: enabled
> step
target state: halted
target halted in ARM state due to breakpoint, current mode: Supervisor
cpsr: 0x40000013 pc: 0x8057c7e0
MMU: enabled, D-Cache: enabled, I-Cache: enabled

pc doesn't change anymore.

The board bsp (with the add_imx_fb(...) line) is this one: 
http://paste.debian.net/hidden/10d828f8/
And this is based on bsp from Freescale MX25 3DS board: 
http://paste.debian.net/hidden/50ada4ee/ or 
arch/arm/mach-imx/mach-mx25_3ds.c in kernel tree

There a two screenshots from ddd-Debugger attached.
The on is code view, and the other the backtrace.

What could be the problem?

(Display is connected via LVDS).

Thanks

Stefan Koch

Attachment: code.png
Description: PNG image

Attachment: backtrace.png
Description: PNG image