Re: Infinite loop in PSOS_INIT()

From: Vic Kulikauskas (vic_at_mmalt.guild.org)
Date: 10/09/04 

Date: Fri, 08 Oct 2004 22:19:04 -0500

"Peter Bushell" <NOpeter.bushell@SPAMsoftware-integrity.com> writes:

> "Arun R" <arun.rangasamy@gmail.com> wrote in message
> news:c8ca6e00.0410080354.75d714fe@posting.google.com...
>> Hi,
>>
>> Problem Summary:
>> While executing the BSP code for our target board (on ARMulator, an
>> ARM instruction set simulator) the processor goes into an infinite
>> loop at PSOS_INIT(). We have no clue as to why this happens. Please
>> read below for more details. Thank-you!
>>
> snip
>>
> endSnip
>
>> This is the snapshot of ARMulator disassembly:
>> 0027b2e4 [0xeafffffd] b 0x27b2e0 ; (pSOS_Ienter + 0x930)
>> 0027b2e8 [0xe10fa000] mrs r10,cpsr
>> 0027b2ec [0xe38a8080] orr r8,r10,#0x80
>> 0027b2f0 [0xe129f008] msr cpsr_cf,r8
>> 0027b2f4 [0xe1a00000] nop ;;;;}}} Infinite
>> 0027b2f8 [0xeafffffd] b 0x27b2f4 ;;;;}}} Loop
>> 0027b2fc [0xe8bd00f0] ldmfd r13!,{r4-r7}
>>
>>
>> If someone can help us in identifying the cause of the problem, and
>> overcoming this, it will be of great help. Also, it will be extremely
>> useful, if someone lists various possible scenarios/exceptional
>> conditions under which PSOS_INIT drives the CPU to an infinite loop.
>> In our case, it goes into an unconditional infinite loop.
>>
>
>
> The loop you are in looks very much as if it might be the pSOS idle task. If
> your own tasks are not running, for whatever reason, this would be where you
> would end up; it's normal! I suggest that you look to see that your tasks
> are properly formed (with infinite loops, so they never return) and properly
> created/initialised.

I'm not familiar with pSOS, but aren't the instructions at 2e8 to
2f4 in the listing above DISabling interrupts? In that case, this
seems to be some fatal error handling routine -- something is
catastrophically wrong, so disable interrupts and hang, to
force a reset (if there is a watchdog) or at least prevent
startup to an unsafe state.

I'm too lazy to look up what bit 7 of cpsr actually does, so I
might be totally out to lunch, in which case just ignore me.

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