[U-Boot] OMAP3: proposal: dont piggy back on ROMCode interrupt vectors

[U-Boot] OMAP3: proposal: dont piggy back on ROMCode interrupt vectors

[Nishanth Menon]

Hi,
Current interrupt vectors[1] are piggy backing on OMAP3 ROM Code vectors
This has the disadvantage that "external boot" option of OMAP GP devices
for booting off NOR devices would probably not function as the interrupt
vectors are not setup.

I had faced this during the port of u-boot-v2 and had done an
implementation[2] for this. would we be interested in pulling this back
in for u-boot-v1? I suppose all OMAP3 devices could benefit from it.

Regards,
Nishanth Menon

Ref:
[1]
http://git.denx.de/?p=u-boot/u-boot-ti.git;a=blob;f=cpu/arm_cortexa8/start.S;h=14a9bd3b039143f92aed2133493aa9ee6a175738;hb=HEAD#l112
[2]
http://git.denx.de/?p=u-boot/u-boot-v2.git;a=blob;f=arch/arm/mach-omap/omap3_core.S;h=dece199faefb3354189347d17cb0709d0ce2ad6c;hb=HEAD#l71

[U-Boot] OMAP3: proposal: dont piggy back on ROMCode interrupt vectors

[Tom Rix]

Nishanth Menon wrote:
> Hi,
> Current interrupt vectors[1] are piggy backing on OMAP3 ROM Code vectors
> This has the disadvantage that "external boot" option of OMAP GP devices
> for booting off NOR devices would probably not function as the interrupt
> vectors are not setup.
>
In general we want to limit dependencies of ROM code.
And it should be moved to omap3 so other cortexa8 users don't have to
code around it.  Like we did for the cache flushing.

> I had faced this during the port of u-boot-v2 and had done an
> implementation[2] for this. would we be interested in pulling this back
> in for u-boot-v1? I suppose all OMAP3 devices could benefit from it.
> 

Poking around it does not look like any of the omap boards define
CONFIG_USE_IRQ so it seems like you really will be creating the
interrupt handlers.  I think this is a good idea as long as the existing
non-interrupts still works. I would be happy to test whatever you want 
to do.  Should we set up a special ti-omap-irq topic branch ?

Tom


> Regards,
> Nishanth Menon
> 
> Ref:
> [1]
> http://git.denx.de/?p=u-boot/u-boot-ti.git;a=blob;f=cpu/arm_cortexa8/start.S;h=14a9bd3b039143f92aed2133493aa9ee6a175738;hb=HEAD#l112
> [2]
> http://git.denx.de/?p=u-boot/u-boot-v2.git;a=blob;f=arch/arm/mach-omap/omap3_core.S;h=dece199faefb3354189347d17cb0709d0ce2ad6c;hb=HEAD#l71
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot
> 
> 

[U-Boot] OMAP3: proposal: dont piggy back on ROMCode interrupt vectors

[Nishanth Menon]

On Tue, Oct 13, 2009 at 7:27 AM, Tom Rix <tom@bumblecow.com> wrote:
> Nishanth Menon wrote:
>>
>> Hi,
>> Current interrupt vectors[1] are piggy backing on OMAP3 ROM Code vectors
>> This has the disadvantage that "external boot" option of OMAP GP devices
>> for booting off NOR devices would probably not function as the interrupt
>> vectors are not setup.
>>
> In general we want to limit dependencies of ROM code.
> And it should be moved to omap3 so other cortexa8 users don't have to
> code around it. ?Like we did for the cache flushing.
>
>> I had faced this during the port of u-boot-v2 and had done an
>> implementation[2] for this. would we be interested in pulling this back
>> in for u-boot-v1? I suppose all OMAP3 devices could benefit from it.
>>
>
> Poking around it does not look like any of the omap boards define
> CONFIG_USE_IRQ so it seems like you really will be creating the
> interrupt handlers. ?I think this is a good idea as long as the existing
> non-interrupts still works. I would be happy to test whatever you want to
> do. ?Should we set up a special ti-omap-irq topic branch ?

it is going to be just a silly little patch.. and given it is a cp15
feature, I think it might be cortex_a8 specific and not OMAP3
specific..
it would be good to have the irqs to be enabled for data abort reports
etc.. but then, that is just my 2 cents..

>
> Tom
>
>
>> Regards,
>> Nishanth Menon
>>
>> Ref:
>> [1]
>>
>> http://git.denx.de/?p=u-boot/u-boot-ti.git;a=blob;f=cpu/arm_cortexa8/start.S;h=14a9bd3b039143f92aed2133493aa9ee6a175738;hb=HEAD#l112
>> [2]
>>
>> http://git.denx.de/?p=u-boot/u-boot-v2.git;a=blob;f=arch/arm/mach-omap/omap3_core.S;h=dece199faefb3354189347d17cb0709d0ce2ad6c;hb=HEAD#l71
>> _______________________________________________
>> U-Boot mailing list
>> U-Boot at lists.denx.de
>> http://lists.denx.de/mailman/listinfo/u-boot
>>
>>
>
>