Porting FreeBSD to Z mainframes idea

[Bjoern A. Zeeb]

On 19 Jan 2020, at 14:21, Shivank Garg wrote:

Hi,

> On Sun, Jan 19, 2020, 3:56 AM Greg 'groggy' Lehey <grog at freebsd.org> wrote:
>
>> On Saturday, 18 January 2020 at 12:43:02 +0530, Shivank Garg wrote:
>>> Hi!
>>> I wish to pursue this idea of porting FreeBSD to IBM Z mainframes.
>>> Currently, there are no BSD derivatives for Z mainframes, and I find the
>>> idea of porting FreeBSD to Z mainframe.
>>>
>>> Someone on IRC suggested to port NetBSD first, as it is easier to port on
>>> different hardware platforms.
>>
>> Agreed, at least at first sight.  Have you discussed this on the
>> NetBSD lists?
>>
>
> No. I haven't discussed this with them yet.

I actually also have no idea about their community thinking about it still.
Would be curious to know.


>>> There is a sponsored internship program called OpenMainFrame
>>> Mentorship. So, I thought to propose this project in this
>>> program. But I'm a beginner and have very little idea about the
>>> whole porting process and challenges faced during it.  I will be
>>> very thankful if you can give suggestions about this, and how much
>>> time will it take for a beginner? The mentorship program is for a
>>> span of 3-4 months.

I think 3-4 months is nowhere near where you can get to anything useful
if you have no clue about the mainframe architecture and low-level
kernel bringup.


>>> Also, If it's too difficult, can there be any doable goals in the
>>> porting process that I can propose for the program and I would
>>> continue the project even after the program is over. I personally
>>> feel the project has good potential, and It will be very helpful in
>>> my learning growth.

The latter probably, the former not so much.  I’ve been contemplating
it on-and-off for more than a decade.

I’ve made make buildworld buildkernel work twice already with skeleton
(read mostly empty implementation) in order to allow people to join and
help.

I’ve asked developers and people who did work on other OSes.
I’ve never found the really good “YES DO IT” case apart from it being
a hobby project.  I’ve found people who were interested in running it.
In order to justify it becoming an official FreeBSD platform to run on
you need more than a single customer sadly and you probably need someone
from the inside at big blue to be able to actually run it on anything
that is not qemu (or some open source emulator).

/bz