Re: [PATCH, ARM, 0/7] Add support for ARMv8-M

[Ramana Radhakrishnan <ramana dot gcc at googlemail dot com>]

On Thu, Dec 17, 2015 at 2:11 AM, Thomas Preud'homme
<thomas.preudhomme@foss.arm.com> wrote:
> Hi,
>
> I'll be posting a patch series intended for the master branch whose aim is to add support for ARMv8-M. As such, it consists mostly of changes to GAS. This patch series does not include changes to support the security extensions beyond assembling related instructions. This will be posted as a separate patch series.

I haven't reviewed this yet but I don't think this patch set should go
into the 2.26 branch yet.

Ramana

>
>
> === Quick overview of ARMv8-M ===
>
> ARMv8-M has two profiles[1]: Baseline and Mainline.  In terms of features they can be defined as:
>
> ARMv8-M Baseline (armv8-m.base):
>  * All ARMv6-M features
>  * 16-bit immediate moves
>  * Wide Branch
>  * Compare & branch if (not) zero
>  * Integer divide
>  * Load/store exclusives
>  * Atomic Load/stores
>  * Security extensions
>
> ARMv8-M Mainline (armv8-m.main):
>  * All ARMv7-M features
>  * Atomic load/stores
>  * Security extensions.
>
> ARMv8-M Mainline with DSP extension (armv8-m.main+dsp):
>  * ARMv8-M Mainline
>  * Those instructions added to ARMv7E-M on top of ARMv7-M.
>
> Note that although certain architectural features of the security extensions are optional for cores implementing ARMv8-M, some of the new instructions are always available in the architecture.
>
> Note also that only the instructions from security extensions are new instructions, all other instructions have previously been available in other ARM Architecture profiles.
>
> [1] http://www.arm.com/products/processors/instruction-set-architectures/armv8-m-architecture.php
>