RE: [ECOS] Is Redboot run in supervisor mode?

[<jameshq at liverpool dot ac dot uk>]

Thank you very much Jonathan. 
Could I ask 4 more questions about the ecos for arm. Thanks a lot in
advance.

I am on ARM target 

Q1. When initializing a user thread (cyg_thread_create()), its mode
will be default to CPSR_SUPERVISOR_MODE.(HAL_THREAD_INIT_CONTEXT) then
the user thread will be loaded into supervisor mode rather than user
mode, is this correct? 

Q2. if so why not use user mode to run the user created thread? 

Q3. Is there any particular reason not using user mode for this? 

Q4. So seems everything in ecos for ARM target are run in supervisor
mode correct(except exception)? no user mode at all.

qiang

Thanks a lot.

-----Original Message-----
From: Jonathan Larmour [mailto:jifl@eCosCentric.com]
Sent: 30 January 2003 15:33
To: Grant Edwards
Cc: Qiang Huang; Ecos-Discuss
Subject: Re: [ECOS] Is Redboot run in supervisor mode?


Grant Edwards wrote:
> On Thu, Jan 30, 2003 at 11:43:20AM -0000, Qiang Huang wrote:
> 
> 
>>When the platform is configured as Redboot startup and load the ecos
app
>>into RAM for debugging, what mode is redboot run in? when loading a
ecos app
>>(by redboot) , what is the starting mode of the ecos app(e.g. when
comes to
>>the entry point of the ecos app: reset_vector) Thanks a lot
> 
> 
> Depends on the architecture.  It's generally in some sort of
> system/supervisor mode.

I believe Qiang is on ARM in which case it's supervisor (SVC) mode for

everything. Even on interrupts we switch to SVC mode as soon as we
can.

Jifl
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