Subject: Re: Some PPC VM weirdness
To: Jochen Kunz <>
From: Matt Thomas <>
List: port-powerpc
Date: 02/19/2005 01:13:03
On Feb 19, 2005, at 12:59 AM, Jochen Kunz wrote:

> On 18 Feb 2005 18:18:53 -0500
> "Nathan J. Williams" <> wrote:
>>> 0xd999ef40: at cpu_switchto+0x44
> [...]
>> In lines like "0xd999ef40: at cpu_switchto+0x44", the 0xd999ef40 is
>> the frame address (on the stack), not a numeric representation of the
>> instruction location.
> OK, stupid user error.
> But why are part of the addresses in the 0x00425xxx range and part in
> 0xd999exxx?

The 0x00425xxx is right after the end of the bss space in the kernel.  
The startup code allocates the USPACEs/PCBs (kernel stacks) for proc0 
and the "idle" proc and then the interrupt stack in the memory right 
after bss.  See INIT_CPUINFO in <powerpc/asm.h> for specifics.  In your 
case, the 0x00425xxx is the interrupt stack.

Matt Thomas                     email:
3am Software Foundry              www:
Cupertino, CA              disclaimer: I avow all knowledge of this