Custom kernel under RPI

[Tim Kientzle]

On Mar 16, 2013, at 10:54 AM, Ian Lepore wrote:

> On Sat, 2013-03-16 at 18:39 +0100, Loïc BLOT wrote:
>> Ok, cross compile is done, i have a modular kernel, but same error
>> appears when i boot. Kernel is blocked at those lines:
>> 
>> Kernel entry at 0x100100 ..
>> Kernel args: (null)
>> 
>> 
> 
> If it doesn't say anything about what FDT it is using before it says
> Kernel Entry, then you aren't using the latest ubldr code.  

Loïc:   How did you set up the MSDOS partition?

The details of how we boot FreeBSD have changed some
over the last couple of months; if you used some old
instructions to set that up, you may not have the right
boot loader configuration to correctly boot the current kernel.


> If it doesn't have the device tree data, it will lock up exactly as
> you're experiencing (without the device data the kernel doesn't have
> enough info to even print an error message).
> 
> A quick way to see if that's the problem is to add to the kernel config:
> 
> options 	FDT_DTB_STATIC
> makeoptions     FDT_DTS_FILE=bcm2835-rpi-b.dts


Keep in mind that Ian's advice here (to compile the FDT
into the kernel) should only be used for debugging.

On RPi, the boot loaders edit the FDT before
handing it to the kernel.   A compiled-in FDT won't
properly reflect a few details that the boot loaders
know about.

If the boot chain is all working properly, a compiled-in
FDT is not needed and not recommended.

Tim