__ARM_ARCH_2__

__ARM_ARCH_2__

[zhaobin xv]

Hi

In linux/arch/arm/boot/compressed/head.S:


#ifndef __ARM_ARCH_2__
        /*
         * Booting from Angel - need to enter SVC mode and disable
         * FIQs/IRQs (numeric definitions from angel arm.h source).
         * We only do this if we were in user mode on entry.
         */
        mrs    r2, cpsr        @ get current mode
        tst    r2, #3            @ not user?
        bne    not_angel
        mov    r0, #0x17        @ angel_SWIreason_EnterSVC
        swi    0x123456        @ angel_SWI_ARM


I don't know what the"__ARM_ARCH_2__" mean?
"__ARM_ARCH_2__" is definded by gcc or definded byarmlinux?
where does it come from? what does it want to do?

__ARM_ARCH_2__

[Russell King - ARM Linux]

On Thu, Aug 08, 2013 at 10:08:02AM +0800, zhaobin xv wrote:
> I don't know what the"__ARM_ARCH_2__" mean?
> "__ARM_ARCH_2__" is definded by gcc or definded byarmlinux?
> where does it come from? what does it want to do?

You could try a few things before posting:

1. You could try grepping the kernel source to find out if anything
   in the kernel defines it.
2. You could try asking google and seeing what it returns.

Either of those will tell you that it's not defined by the kernel but by
the compiler.  For me, the first link on google explains it really well.

Thanks.

__ARM_ARCH_2__

[Dave Martin]

On Thu, Aug 08, 2013 at 09:27:19AM +0100, Russell King - ARM Linux wrote:
> On Thu, Aug 08, 2013 at 10:08:02AM +0800, zhaobin xv wrote:
> > I don't know what the"__ARM_ARCH_2__" mean?
> > "__ARM_ARCH_2__" is definded by gcc or definded byarmlinux?
> > where does it come from? what does it want to do?
> 
> You could try a few things before posting:
> 
> 1. You could try grepping the kernel source to find out if anything
>    in the kernel defines it.
> 2. You could try asking google and seeing what it returns.
> 
> Either of those will tell you that it's not defined by the kernel but by
> the compiler.  For me, the first link on google explains it really well.

Should that code go away?  I believe we don't support v2 or v3 any more...
Did teqp actually work in 32-bit modes?

Cheers
---Dave

Re: __ARM_ARCH_2__

[Alexander Shiyan]

> On Thu, Aug 08, 2013 at 09:27:19AM +0100, Russell King - ARM Linux wrote:
> > On Thu, Aug 08, 2013 at 10:08:02AM +0800, zhaobin xv wrote:
> > > I don't know what the"__ARM_ARCH_2__" mean?
> > > "__ARM_ARCH_2__" is definded by gcc or definded byarmlinux?
> > > where does it come from? what does it want to do?
> > 
> > You could try a few things before posting:
> > 
> > 1. You could try grepping the kernel source to find out if anything
> >    in the kernel defines it.
> > 2. You could try asking google and seeing what it returns.
> > 
> > Either of those will tell you that it's not defined by the kernel but by
> > the compiler.  For me, the first link on google explains it really well.
> 
> Should that code go away?  I believe we don't support v2 or v3 any more...
> Did teqp actually work in 32-bit modes?

"ARM: 7770/1: remove residual ARMv2 support from decompressor":
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/arch/arm/boot/compressed/head.S?id=52c08a9e399739979027ea1e463f5529476da104

---

__ARM_ARCH_2__

[Dave Martin]

On Thu, Aug 08, 2013 at 10:03:55PM +0400, Alexander Shiyan wrote:
> > On Thu, Aug 08, 2013 at 09:27:19AM +0100, Russell King - ARM Linux wrote:
> > > On Thu, Aug 08, 2013 at 10:08:02AM +0800, zhaobin xv wrote:
> > > > I don't know what the"__ARM_ARCH_2__" mean?
> > > > "__ARM_ARCH_2__" is definded by gcc or definded byarmlinux?
> > > > where does it come from? what does it want to do?
> > > 
> > > You could try a few things before posting:
> > > 
> > > 1. You could try grepping the kernel source to find out if anything
> > >    in the kernel defines it.
> > > 2. You could try asking google and seeing what it returns.
> > > 
> > > Either of those will tell you that it's not defined by the kernel but by
> > > the compiler.  For me, the first link on google explains it really well.
> > 
> > Should that code go away?  I believe we don't support v2 or v3 any more...
> > Did teqp actually work in 32-bit modes?
> 
> "ARM: 7770/1: remove residual ARMv2 support from decompressor":
> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/arch/arm/boot/compressed/head.S?id=52c08a9e399739979027ea1e463f5529476da104

Job done, then

Cheers
---Dave