[U-Boot] U-boot for 64bit ARMv8

[U-Boot] U-boot for 64bit ARMv8

[Richard Schmitt]

Is anyone considering porting/supporting uboot for ARMv8. ?Our initial investigation of boot loader support for ARMv8 indicates that the only boot loader currently being targeted is UEFI. ?

The decisions we need to make are:
- Do we move to UEFI on ARM?
- Can we leverage someone else's enablement of ARMv8?
- Do we provide our own enablement of ARMv8?

Any opinions?

Rich

[U-Boot] U-boot for 64bit ARMv8

[Tom Rini]

On Wed, Jun 12, 2013 at 06:10:06AM -0700, Richard Schmitt wrote:

> Is anyone considering porting/supporting uboot for ARMv8. ?Our initial
> investigation of boot loader support for ARMv8 indicates that the only
> boot loader currently being targeted is UEFI. ?
> 
> The decisions we need to make are:
> - Do we move to UEFI on ARM?
> - Can we leverage someone else's enablement of ARMv8?
> - Do we provide our own enablement of ARMv8?
> 
> Any opinions?

The general push from ARM Ltd is to use UEFI.  I would strongly suspect
that there are U-Boot forks that companies that have announced they are
doing ARMv8 chips have something as a stop-gap until they have the
functionality they want in uEFI.

I am quite open to ARMv8 support being added to U-Boot and addressing
the concerns companies may have.  Sometimes it seems like "GPLv2+" makes
people think "Project will be moving to GPLv3, RUN AWAY!" when all it
really means is "Project is GPLv2+, will evaluate the appropriateness of
later versions".

-- 
Tom
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[U-Boot] U-boot for 64bit ARMv8

[Albert ARIBAUD]

Hi Tom,

On Wed, 12 Jun 2013 12:33:39 -0400, Tom Rini <trini@ti.com> wrote:

> On Wed, Jun 12, 2013 at 06:10:06AM -0700, Richard Schmitt wrote:
> 
> > Is anyone considering porting/supporting uboot for ARMv8. ?Our initial
> > investigation of boot loader support for ARMv8 indicates that the only
> > boot loader currently being targeted is UEFI. ?
> > 
> > The decisions we need to make are:
> > - Do we move to UEFI on ARM?
> > - Can we leverage someone else's enablement of ARMv8?
> > - Do we provide our own enablement of ARMv8?
> > 
> > Any opinions?
> 
> The general push from ARM Ltd is to use UEFI.  I would strongly suspect
> that there are U-Boot forks that companies that have announced they are
> doing ARMv8 chips have something as a stop-gap until they have the
> functionality they want in uEFI.
> 
> I am quite open to ARMv8 support being added to U-Boot and addressing
> the concerns companies may have.  Sometimes it seems like "GPLv2+" makes
> people think "Project will be moving to GPLv3, RUN AWAY!" when all it
> really means is "Project is GPLv2+, will evaluate the appropriateness of
> later versions".

This is not specific to 64-Bit ARM support, though. GPLv2+ has been
there for very long. Aren't companies educated by now? (I am quite open
to helping spread education, anyway)

Amicalement,
-- 
Albert.

[U-Boot] U-boot for 64bit ARMv8

[Tom Rini]

On Wed, Jun 12, 2013 at 06:54:54PM +0200, Albert ARIBAUD wrote:
> Hi Tom,
> 
> On Wed, 12 Jun 2013 12:33:39 -0400, Tom Rini <trini@ti.com> wrote:
> 
> > On Wed, Jun 12, 2013 at 06:10:06AM -0700, Richard Schmitt wrote:
> > 
> > > Is anyone considering porting/supporting uboot for ARMv8. ?Our initial
> > > investigation of boot loader support for ARMv8 indicates that the only
> > > boot loader currently being targeted is UEFI. ?
> > > 
> > > The decisions we need to make are:
> > > - Do we move to UEFI on ARM?
> > > - Can we leverage someone else's enablement of ARMv8?
> > > - Do we provide our own enablement of ARMv8?
> > > 
> > > Any opinions?
> > 
> > The general push from ARM Ltd is to use UEFI.  I would strongly suspect
> > that there are U-Boot forks that companies that have announced they are
> > doing ARMv8 chips have something as a stop-gap until they have the
> > functionality they want in uEFI.
> > 
> > I am quite open to ARMv8 support being added to U-Boot and addressing
> > the concerns companies may have.  Sometimes it seems like "GPLv2+" makes
> > people think "Project will be moving to GPLv3, RUN AWAY!" when all it
> > really means is "Project is GPLv2+, will evaluate the appropriateness of
> > later versions".
> 
> This is not specific to 64-Bit ARM support, though. GPLv2+ has been
> there for very long. Aren't companies educated by now? (I am quite open
> to helping spread education, anyway)

Indeed, it applies to the project as a whole.  I have however, gotten
some private feedback that to me says that there are companies out there
afraid that because we retain our "+" we're going to switch to GPLv3 any
minute, rather than keeping our options open, should some future GPL
provide a compromise both developers, companies and regular consumers
can live with.

-- 
Tom
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[U-Boot] U-boot for 64bit ARMv8

[Albert ARIBAUD]

Hi Tom,

On Wed, 12 Jun 2013 13:47:18 -0400, Tom Rini <trini@ti.com> wrote:

> On Wed, Jun 12, 2013 at 06:54:54PM +0200, Albert ARIBAUD wrote:
> > Hi Tom,
> > 
> > On Wed, 12 Jun 2013 12:33:39 -0400, Tom Rini <trini@ti.com> wrote:
> > 
> > > On Wed, Jun 12, 2013 at 06:10:06AM -0700, Richard Schmitt wrote:
> > > 
> > > > Is anyone considering porting/supporting uboot for ARMv8. ?Our initial
> > > > investigation of boot loader support for ARMv8 indicates that the only
> > > > boot loader currently being targeted is UEFI. ?
> > > > 
> > > > The decisions we need to make are:
> > > > - Do we move to UEFI on ARM?
> > > > - Can we leverage someone else's enablement of ARMv8?
> > > > - Do we provide our own enablement of ARMv8?
> > > > 
> > > > Any opinions?
> > > 
> > > The general push from ARM Ltd is to use UEFI.  I would strongly suspect
> > > that there are U-Boot forks that companies that have announced they are
> > > doing ARMv8 chips have something as a stop-gap until they have the
> > > functionality they want in uEFI.
> > > 
> > > I am quite open to ARMv8 support being added to U-Boot and addressing
> > > the concerns companies may have.  Sometimes it seems like "GPLv2+" makes
> > > people think "Project will be moving to GPLv3, RUN AWAY!" when all it
> > > really means is "Project is GPLv2+, will evaluate the appropriateness of
> > > later versions".
> > 
> > This is not specific to 64-Bit ARM support, though. GPLv2+ has been
> > there for very long. Aren't companies educated by now? (I am quite open
> > to helping spread education, anyway)
> 
> Indeed, it applies to the project as a whole.  I have however, gotten
> some private feedback that to me says that there are companies out there
> afraid that because we retain our "+" we're going to switch to GPLv3 any
> minute, rather than keeping our options open, should some future GPL
> provide a compromise both developers, companies and regular consumers
> can live with.

Maybe some FAQ entry about the licence [version] on the Denx project
might make things easier.

Amicalement,
-- 
Albert.

[U-Boot] U-boot for 64bit ARMv8

[TigerLiu at viatech.com.cn]

Hi, experts:
I found ARMv8/Exceptions.S only created a 8 items vector table.

But based on ARMv8 Arch Ref Manual, it should create 16 items in a
vector table:
Current Exception level with SP_EL0 : 4 items
Current Exception level with SP_Elx : 4 items
EL immediately lower than target_EL is using AARCH64 : 4 items
EL immediately lower than target_EL is using AARCH32 : 4 items

Are current 8 items enough? Or will patch it in the future?

Best wishes,

[U-Boot] U-boot for 64bit ARMv8

[FengHua]

> -----Original Messages-----
> From: TigerLiu at viatech.com.cn
> Sent Time: 2014-01-23 14:44:36 (Thursday)
> To: u-boot at lists.denx.de
> Cc: 
> Subject: [U-Boot]  U-boot for 64bit ARMv8
> 
> Hi, experts:
> I found ARMv8/Exceptions.S only created a 8 items vector table.
> 
> But based on ARMv8 Arch Ref Manual, it should create 16 items in a
> vector table:
> Current Exception level with SP_EL0 : 4 items
> Current Exception level with SP_Elx : 4 items
> EL immediately lower than target_EL is using AARCH64 : 4 items
> EL immediately lower than target_EL is using AARCH32 : 4 items
> 
> Are current 8 items enough? Or will patch it in the future?
> 

Currently, u-boot for aarch64 does not provide any run time service.
So, the low level exception entries are not implemented. 

Best wishes,