Kernel Initialization Problem

[Stefan Kalkowski]

Hi,

On 07/24/2014 09:27 AM, chirag garg wrote:
> Hi
> 
> As I am working on iMx6 Board. I am trying to use Arm_gic Interrupt
> Controller instead of TZIC used in iMx53 board. Previously I was using
> Pic_based:: Pic( ).
> 

You should use the PIC for Cortex A9, like Aditya Kousik used it in the
original patch to enable i.MX6:

  "class Pic : public Cortex_a9::Pic { };"

> As the version change in Genode 14.05,
> Inside : Genode/repos/base-hw/src/core/kernel/kernel.cc
> 
>  we are calling " init_kernel_uniprocessor( ) " to set up the env for other
> core and then we are calling  " init_kernel_multiprocessor( ) " which is
> using *pic( )* call at various places which is returning a singleton
> object.

You shouldn't need to change anything in kernel.cc. If you just describe
the execution flow, then you're right: the firstly executing CPU
initializes certain data-structures (e.g. kernels initial page tables),
and then it wakes up all other CPUs (if configured, and available). Then
all CPUs, including the first one, are executing the code in
"init_kernel_multiprocessor".

One remark: did you set the PROCESSORS variable in
"repos/base-hw/mk/spec-hw_imx6.mk" to some value above "1"? That
variable got introduced in Genode release 14.04 as part of the
preliminary SMP support. Please assure that you set that variable to
one, because until now the SMP for Cortex A9 isn't tested at all, and
probably is not working correctly.

> 
> 
> extern "C" void init_kernel_multiprocessor()
> {
> .....
> .....
> init_trustzone(*pic( )*);
> ......
> }
>  and the pic( ):
> 
> Pic * pic() {   * return unmanaged_singleton<Pic>( ) *;  }
> 
> and at this point it is not able to return the object
> *unmanaged_singleton<Pic>(
> ) , *what could be the problem ??

I don't know what you mean by: "not able to return the object". Does it
mean you get a null-pointer, or isn't the function returning at all,
blocking infinitely? Or does it (page-)fault within the Pic() constructor?

Regards

> 
> 
> Regards
> 
> Chirag Garg
> IIT Madras , Rise Lab
> 
> 
> 
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-- 
Stefan Kalkowski
Genode Labs

http://www.genode-labs.com/ · http://genode.org/