[ECOS] Drivers and related...

[ECOS] Drivers and related...

[Rafael Rodríguez Velilla]

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   I'm porting eCos for a SOC with an embedded ARM. Everything is going
quite right but now I find the following problem with eCos philosophy.
My problem is quite simple:
1 My SOC has a lot of devices embedded (such as UARTS, display
controller, keyboard controller, interrupts controller, and so on)
2 My SOC is in a platform with some peripherals such as the display
itself, the 3volt to 5 volt converter and so on.

I want to integrate the drivers in eCos so that the user can configure
the platform in the same way as in the rest of the operating system,
that is, with cdl.

Where should I put all these drivers? under hal/MICROPP/arch o under
hal/MICROPP/tema, a mix of both or even as an independent package ?
(tema is the name of the platform and MICROPP the name of the SOC)

I have created a new architecture, it has an embedded ARM but I
considered that it can be considered a new architecture because of all
the extra components that  are indefectibly together. Do you consider
this a correct assumption?

Tank you in advance.



--
Rafael Rodríguez Velilla        rrv@tid.es
Telefónica I+D          http://www.tid.es
Telf: +34 - 91 337 4270

Re: [ECOS] Drivers and related...

[Jonathan Larmour]

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Rafael Rodríguez Velilla wrote:
> 
>    I'm porting eCos for a SOC with an embedded ARM. Everything is going
> quite right but now I find the following problem with eCos philosophy.
> My problem is quite simple:
> 1 My SOC has a lot of devices embedded (such as UARTS, display
> controller, keyboard controller, interrupts controller, and so on)
> 2 My SOC is in a platform with some peripherals such as the display
> itself, the 3volt to 5 volt converter and so on.
> 
> I want to integrate the drivers in eCos so that the user can configure
> the platform in the same way as in the rest of the operating system,
> that is, with cdl.
> 
> Where should I put all these drivers? under hal/MICROPP/arch o under
> hal/MICROPP/tema, a mix of both or even as an independent package ?
> (tema is the name of the platform and MICROPP the name of the SOC)

It depends on the driver. Things like interrupt controllers need to be
dealt with in the HAL; things like serial drivers should be under
devs/serial at the top level. Given there is no formal infrastructure for
the other devices (keyboard, display) you say about, integrating them into
the platform HAL (i.e. tema) may be sufficient.
 
> I have created a new architecture, it has an embedded ARM but I
> considered that it can be considered a new architecture because of all
> the extra components that  are indefectibly together. Do you consider
> this a correct assumption?

Whether a CPU has peripherals on-chip or off-chip makes little difference
on the operating system level. So treating it as a platform, not an
architecture, would be better. Generally peripherals are macrocells, so you
could easily find them again on a different CPU, so in this case putting
the drivers into separate packages would ease code reuse if code reuse is
likely.

Jifl
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