[ECOS] .pool directives and UNMAPPED in ARM

[ECOS] .pool directives and UNMAPPED in ARM

[???]

Hi!
I have some question about some code in file "vectors.S" used in ARM architecture.

1. What is the meaning of ".pool" directive?
2. What is the usage of "UNMAPPED" reset_vector?

Re: [ECOS] .pool directives and UNMAPPED in ARM

[Jonathan Larmour]

??? wrote:
> 
> Hi!
> I have some question about some code in file "vectors.S" used in ARM architecture.
> 
> 1. What is the meaning of ".pool" directive?

Hi ???!

From the GNU assembler info file:

`.ltorg'
     This directive causes the current contents of the literal pool to
     be dumped into the current section (which is assumed to be the
     .text section) at the current location (aligned to a word
     boundary).

`.pool'
     This is a synonym for .ltorg.


> 2. What is the usage of "UNMAPPED" reset_vector?

I don't understand the question. If you mean why is it UNMAPPED_PTR rather
than PTR, then this applies for targets with MMUs in which case the
unmapped (i.e. unrelocated physical) address of the reset vector is what
needs to go into the reset vector slot, not the mapped (post relocation
virtual) address.

Jifl
-- 
Red Hat, 35 Cambridge Place, Cambridge, UK. CB2 1NS  Tel: +44 (1223) 728762
"Plan to be spontaneous tomorrow."  ||  These opinions are all my own fault

Re: [ECOS] .pool directives and UNMAPPED in ARM

[김홍성]

> ??? wrote:
> > 
> > Hi!
> > I have some question about some code in file "vectors.S" used in ARM architecture.
> > 
> > 1. What is the meaning of ".pool" directive?
> 
> Hi ???!
> 
> >From the GNU assembler info file:
> 
> `.ltorg'
>      This directive causes the current contents of the literal pool to
>      be dumped into the current section (which is assumed to be the
>      .text section) at the current location (aligned to a word
>      boundary).
> 
> `.pool'
>      This is a synonym for .ltorg.


Thanks your help!!
But still now I don't understand the meaning exactly.
Can you explain more deeply using examples if possible?

 
> 
> > 2. What is the usage of "UNMAPPED" reset_vector?
> 
> I don't understand the question. If you mean why is it UNMAPPED_PTR rather
> than PTR, then this applies for targets with MMUs in which case the
> unmapped (i.e. unrelocated physical) address of the reset vector is what
> needs to go into the reset vector slot, not the mapped (post relocation
> virtual) address.

Yes, That's my question.
But I am sorry too that I can't understand completely why shoud use UNMAPPED_PTR for reset.
Can you explain using any examples?


> 
> Jifl
> -- 
> Red Hat, 35 Cambridge Place, Cambridge, UK. CB2 1NS  Tel: +44 (1223) 728762
> "Plan to be spontaneous tomorrow."  ||  These opinions are all my own fault
>