On 2016-Sep-24, at 2:11 PM, Warner Losh <[email protected]> wrote:

> On Fri, Sep 23, 2016 at 8:29 PM, Mark Millard <[email protected]> wrote:
>> [A resend since I forget to list free-arm in the To: the first time.]
>> 
>> From https://www.freebsd.org/platforms/arm.html :
>> 
>>> 32-bit ARM is officially a Tier 2 architecture, as the FreeBSD project does 
>>> not provide official releases or pre-built packages for this platform due 
>>> to it primarily targeting the embedded arena. However, FreeBSD/ARM is being 
>>> actively developed and maintained, is well supported, and provides an 
>>> excellent framework for building ARM-based systems. FreeBSD/arm supports 
>>> ARMv4 and ARMv5 processors. FreeBSD/armv6 supports ARMv6 and ARMv7 
>>> processors, including SMP on the latter.
>> 
>> "does not provide official releases or pre-built packages"?
>> 
>>> # uname -apKU
>>> FreeBSD rpi2 11.0-PRERELEASE FreeBSD 11.0-PRERELEASE #5 r304943M: Sun Aug 
>>> 28 03:17:54 PDT 2016     
>>> markmi@FreeBSDx64:/usr/obj/clang/arm.armv6/usr/src/sys/RPI2-NODBG  arm 
>>> armv6 1100502 1100502
>> 
>>> # pkg search '.*' | wc
>>>  21349  155540 1596736
>> 
>> Will 11.0-RELEASE change the tier level for any of the specific arm-armv6 
>> variants that have FreeBSD-11.0-*-arm-armv6-*.img* files built, such as for 
>> RPI2?
>> 
>> Even if all the officially built arm-armv6 variants stay tier 2, the wording 
>> on the web page likely needs to be changed because so much is built and 
>> available that the above quote claims is not available.
> 
> armv6 is basically Tier 1 right now, though not as Tier 1 as i386 or
> amd64 due to the fragmented nature of the arm world. On the platforms
> we run on and create releases for, however, it's my opinion that it is
> Tier 1: it has been running in production a while, things people
> expect from a FreeBSD system are present, you can get decent support
> if you ask questions, there's no known major gotchas in deploying this
> hardware. The only remaining annoying issue is the 'u-boot' problem
> where we have to have a different u-boot image for every board and no
> standardized way to convert a 'generic' image into one that's specific
> for specific boards. For x86 this is all done with the installer since
> that boot environment is more standardized. Does this last issue keep
> arm from being Tier 1? That's a judgement call, but I think the
> project should promote w/o this last issue.

Interesting and good to know. Thanks.

I might have guessed that going along with the u-boot issue would be the fanout 
in:

11.0/sys/arm/ . . .

allwinner/a10/
allwinner/a20/
allwinner/a31/
allwinner/a83t/
allwinner/h3/
. . .
broadcom/bcm2835/
. . .

(Full list not shown.)

I was thinking that this might make the tier level specific to the status of 
each such directory's content so that it was the combination of that and the 
sysutils/u-boot-*/ status that made the difference for assigning the level.  
I'd guess that lack of a usable directory in either place would not be tier 2 
even. Similarly until the required sys/arm/*/* and sysutils/u-boot-*/ 
directory-tree content have reached a sufficiently complete status.

I'd expect that there will always be a lag for what exists in the world vs. 
what has these materials worked out in FreeBSD.


>> Also from https://www.freebsd.org/platforms/arm.html :
>> 
>>> Initial support for 64-bit ARM is complete. 64-bit ARM platforms follow a 
>>> set of standard conventions, and a single FreeBSD build will work on 
>>> hardware from multiple vendors. As a result, FreeBSD will provide official 
>>> releases for FreeBSD/arm64 and packages will be available. FreeBSD/arm64 is 
>>> on the path to becoming a Tier 1 architecture.
>> 
>> Will 11.0-RELEASE make arm64/aarch64 Tier 1?
>> 
>> [I will note that, while there are no official builds for the Pine64 family 
>> (A64 based) that are under the Allwinner arm activity, the SOC's involved 
>> are Cortex-A53 64-bit arm based. They likely do not fit in the "standard 
>> conventions" or arm64/aarch64 would be where they would have been supported. 
>> Some rewording might be appropriate for the above quote as well.]
> 
> No. aarch64 isn't Tier 1 yet. There's many small bits that are
> missing. It is quite solidly Tier 2, but we don't have a linker, we
> don't have widespread hardware availability, we don't have production
> experience with the platform. Most things work, but there's still some
> gotchas. There's still the 'u-boot' problem with many arm64 systems
> because for systems that use u-boot to bootstrap UEFI, you need a
> different image for each board (some closely related board families
> can get by with one to be pedantic). All these issues are still
> significant barriers to production use. It's not been officially
> promoted yet and I don't think the time is quite right yet.

Intersting as well. I'd guess that conceptually this probably would apply to 
both:

sys/arm/allwinner/a64/ and sysutils/u-boot/pine64/
(presuming, contrary to fact, that 11.0 had sys/arm/allwinner/a64/ )

and. . .

sys/arm64/cavium/
sys/arm64/cloudabi64/

So just sys/arm/ vs. sys/arm64/ for an aarch64 would not really make a 
difference yet for tier level.

> Warner

Thanks again for the notes.

===
Mark Millard
markmi at dsl-only.net

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