Freescale imx35 kernel 3.6, no kernel boot messages

[Johannes Braun]

> currently I`m trying to port the DENX 3.6 stable kernel for the flea3
> board from carmedialabs. The board is based on a Freescale imx35
> processor. Therefore I had a look at Stefano Bacics fork in the DENX
> git repo, where I found a branch for the flea3 board. Compiling the
> kernel required a modification of arch/arm/mach-imx/mach-flea3.c where
> I had to replace .boot_params against .atag_offset in MACHINE_START.
> Know my problem is that I can't see kernel boot messages. The boot uart
> is uart2. So it has to be ttymxc2.
>
> The machine id is also added to arch/arm/tools/mach-types.h
> +flea3 MACH_FLEA3 FLEA3 3668
>
> After the message:
> Uncompressing Kernel Image ... OK
> the board is completly silent and I can`t see any boot messages.
>
> But the kernel does not hang. I checked it with a bdi3000. When I step
> through the start_kernel() function, there are some printk outputs.
> These outputs are reached, but nothing is show via uart2.
>
> As I read, newer kernels like 3.6 are using the common clk framework.
> Do I have to enable the clock for the uart2 in
> arch/arm/mach-imx/clk-imx35.c via clk_prepare_enable(clk[uart2_gate])?
> I checked this, but had no success.
>
> DEBUG_LL is disabled.
>
> In uboot I didn`t change anything. ttymxc2 is configured in the
> bootparams. All the parameters are the same as with the 3.0.0 kernel.
>
> Did someone had success running a kernel greater than 3.0 on a
> freescale imx35 board?

I found the issue. There was a parameter missing in MACHINE_START. I
added .handle_irq = imx35_handle_irq and now I can see the boot output
over uart2.