ARMv8 [FreeBSD WIKI]

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
===== FreeBSD Developer Summit: ARMv8 (AArch64/ARM64) =====

==== Overview ====

This is a planning session of next steps for the ARMv8 port.

==== Goals ====

The initial bootstrapping of %%FreeBSD%% to ARM64 is nearly complete; we need to start planning the next steps towards getting ARMv8 adopted as a Tier1 architecture. The aim of this group is to bring interested parties in the ARM port discuss the steps needed to achieve this goal and identify areas that require work, their priority and how to achieve them.

==== Topics ====

^ # ^ Topic Description ^
| 1 | Update on AArch64 port |
| 2 | CPU Scaling |
|  | * Minimum support for 48 cores |
| 3 | Power Management |
|  | * PSCI |
|  | * big.LITTLE |
| 4 | Virtualization |
|  | * bhyve |
|  | * Xen |
| 5 | Workload Optimization |
|  | * What are the top 5 frameworks |
| 6 | Toolchain |
|  | * LLVM |
|  | * LLDB |
|  | * LLD |

==== Attending ====

In order to attend you need register for the [[/DevSummit|developer summit]] as well as by email for the session and be confirmed by the working group organizer.  Follow the guidelines described on the [[DevSummit/201506|main page]] or what you received by email.  For questions or if in doubt ask andrew.wafaa@arm.com

**Please do NOT add yourself here.** Your name will appear automatically once you have received the confirmation email. You need to put your name on the general [[DevSummit/201506|developer summit]] attendees list though.

^ Name ^ Username / Affiliation ^ Topics of Interest ^ Notes ^
| [[/AndyWafaa|AndyWafaa]] | ARM Ltd. |  | Session chair |
| [[/ZbigniewBodek|ZbigniewBodek]] | zbb |  | Working on ARMv8 port |
| [[/AndrewTurner|AndrewTurner]] | andrew |  | Working on ARMv8 port |
| [[/JulienGrall|JulienGrall]] | Citrix (Xen Project) | Virtualization (Xen) |  |
| [[/LarryWikelius|LarryWikelius]] | Cavium Inc. |  |  |
| [[/GlenBarber|GlenBarber]] | gjb |  |  |
| [[/ArunThomas|ArunThomas]] | BAE Systems |  |  |
| [[/JustinHibbits|JustinHibbits]] | jhibbits | Clock & Power Domain |  |
| [[/StaceySon|StaceySon]] | sson | QEMU |  |
| [[/BrooksDavis|BrooksDavis]] | brooks |  |  |
| [[/DavidChisnall|DavidChisnall]] | theraven |  |  |
| [[/EricLeBlan|EricLeBlan]] |  |  |  |
| [[/MichaelBrinke|MichaelBrinke]]-Engel |  |  |  |

==== Notes ====

==== Results ====
Topics

**Update on AArch64 port**

[[/arm64|arm64 Wiki page]]

  * %%FreeBSD%% Foundation sponsored by ARM & Cavium Work carried out by Andrew Turner & %%SemiHalf%%. Work is progressing well but not necessarily as quick as some would like. AArch64 is in HEAD, usable with QEMU and Foundation Model with some limitations. Appears some issues remain with PMAP limiting toolchain. Targeting Tier1 architecture for FreeBSD11

  * ARM sponsoring University of Cambridge to port Dtrace and HW Performance Counters Initial code in HEAD

zbb demoed %%FreeBSD%% running on a Cavium %%ThunderX%% platform utilising 48cores.

**CPU Scaling**
  * Able to boot with48 cores but stability is an issue Unsure as to where the instability lies
  * Lack of knowledge/experience with high core counts No fundamental issues expected, just new territory

**Power Management**

ARM expressed importance of Power Management
  * PSCI driver is now in HEAD
  * More details covered in the [[DevSummit/201506/ClockDomains|Clock/Power Domain session]] from the previous day

**Virtualization**
  * bhyve There is a GSOC project to port %%FreeBSD%%/buhyve to ARMv7 (32bit). Reason is easy access to hardware, maturity of %%FreeBSD%% on ARMv7. Use 32bit as foundation and if possible port to AArch64 during GSOC
  * Xen Citrix have ported Xen. %%FreeBSD%% on AArch64 works as %%DomU%% guest only. Dom0 still to be worked on

**Workload Optimization**
  * What are the top 5 frameworks? - Standard web stack NGINX is the big ticket item - Language runtimes Erlang is important

**Toolchain**
  * LLVM Support is upstream but may not be completely in %%FreeBSD%%'s implementation. %%FreeBSD%%'s use is extensive and is catching issues that others have not seen
  * LLDB Work is ongoing
  * LLD Work is ongoing. Least developed of the toolchain stack?
  * GDB jhb volunteers to work on port
  * %%OpenMP%% (LLVM libomp)(Adrian's WIP for libgomp) Deemed important, need someone to look at it

**GPU / GPGPU support?**

What are the plans for support?
  * opencl fully support AArch64 ARM is woring on this, not necessarily with %%FreeBSD%% in mind

**Fault Tolerance / High Availability**
Key item for %%XinuOS%%. No ideas on what HW will implement specific HA methods. Software based HA should be no problem

**Application specific offload engines**

Some silicon vendors are deploying specific engines. Need to work with vendors to implement support.
  * Cavium have announced: compression / decompression, crypto, regex

----

{{tag>Historical}}