[okl4-developer] okl4 faults on arm1136

[Geoffrey Lee]

On Tue, Jul 22, 2008 at 08:59:39PM -0500, Ashish Bijlani wrote:
> Here are more debugging messages:
> 
> Debug: Setting up rootserver mappings: V:3000 P:8012a000 S:1000 (0)
> Debug: Setting up rootserver mappings: V:100000 P:801a0000 S:39984 (1)
> Debug: Setting up rootserver mappings: V:142000 P:80602000 S:3e02c (2)
> Debug: Setting up rootserver mappings: V:2000 P:80123000 S:1000 (3)
> Debug: Setting up rootserver mappings: V:200000 P:80700000 S:100000 (4)
> 
> The system doesn't seem to be loading rootserver info properly in the
> function "asm_switch_to".
> I guess the stack pointer "sp" in function "asm_switch_to" is not
> being setup correctly.
> 
> I see the following line commented out in function "init_root_servers"
> 
> /** @todo FIXME: Enable once user-level crt0's are fixed - awiggins. */
> //tcb->set_user_sp((addr_t)(server_info->sp));


Hi Ashish,

Please have a look at the user-level crt0.  You will find the sp for the
roottask is set to zero, and the stack address is obtained from
the bootinfo.

> 
> Why is the stack pointer not set as per the rootserver info struct?
> 
> Function "asm_switch_to" passes STACK_TOP as the stack pointer to the
> roottask. Could this be the reason?


No, the behavior of asm_switch_to() is correct.  What you see in 
asm_switch_to() is the kernel stack pointer being reset to STACK_TOP
and has nothing to do with the value of the user thread's stack pointer.


> 
> -Ashish

	-gl

> 
> 
> On Tue, Jul 22, 2008 at 8:30 PM, Ashish Bijlani
> <ashish.bijlani at gmail.com> wrote:
> > Hi,
> >
> > OKL4 faults on arm1136jfs when starting the roottask at addr
> > 0xf000e0c0 with stack top = 0x3f8 and stack size 1024 bytes. Any idea
> > why? I'm loading okl4 at 0x8010 0000 (start of the RAM).
> >
> > Below are the boot msgs:
> >
> > Uncompressing OKL4.....................done, booting the kernel.
> > Info: Interrupt Controller found at 0xf90fe000 (rev. 2.1) with 96 interrupts
> > OKL4 - (provider: Open Kernel Labs) built on Jul 22 2008 04:23:06
> > using gcc version 3.4.4.
> > Initializing kernel debugger...
> > Initializing interrupts...
> > Info: Disabling FIQs
> > Processor Id => 4107b362: v6, ARM1136, rev 2
> > VFP CoProcessor Supported
> > VFP System Id => 410120b4: ARM, Format 1, Precision Single+Double,
> > VFPv2, PartNo 20, Rev 5,
> > Initializing timer...
> > Info: Unmasking IRQ 37
> > TLB lock: vectors @ ffff0000
> > TLB lock: utcb @ ff000000
> > TLB lock: kernel @ f0000000
> > Locked kernel into TLB
> > Init mutexids for 256 mutexs
> > Init clistids for 16 clists
> > Initialising scheduler...
> > Switching to idle thread
> > Debug: Moving to addr f00079e4 with stack f001f3f8
> > Initializing root servers
> > root-servers: utcb_area: eff00100 (64KB)
> > creating root server (00000001)
> > Debug: System Started
> > Debug: Current Thread ID = 0x1d1e1d1e
> > Debug: Next Thread ID = 0x00000001
> >
> > Thanks,
> > Ashish
> >
> 
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