x86_64 support?

[Chris Johns]

On 10/2/17 10:52 pm, Jan Sommer wrote:
> Am 2017-02-09 22:07, schrieb Chris Johns:
>> On 10/02/2017 02:22, Joel Sherrill wrote:
>>> On Feb 9, 2017 7:29 AM, "Jan Sommer" <soja-lists at aries.uberspace.de
>>> <mailto:soja-lists at aries.uberspace.de>> wrote:
>>>
>>>     Hello,
>>>
>>>     As far as I see there is no support for x86_64 yet. I found that
>>>     there was a GSoC proposal to add BSP for the architecture, but I am
>>>     not sure if it was accepted.
>>>
>>>     Does someone know what is the current status of 64bit support and
>>>     what would be missing for a working BSP with a PCI and clock driver?
>>>
> [...]
>>
>> I recently updated the x86_64 project ticket and I suggest checking it
>> ...
>>
>>  https://devel.rtems.org/ticket/2898
>>
> 
> Thank you for all the information. I am not sure that we have the
> experience for such a project available atm.
> I am not that familiar with the details of x86, but would it be possible
> to run a i386-BSP-application on a 64bit-CPU (e.g. something like
> http://www.systerra.de/documents/IDAN-CMA24GS_DS1.pdf)?

The i386 should run using a suitable multiboot boot loader (iPXE etc). I
am not sure about the gigabit ethernet because I could see the specific
device.

Note, libbsd has an issue on the i386 PC I have not looked into and
fixed. The support broke with the recent upgrade to the latest FreeBSD
version.

> Given that we don't need any 64bit features, is it much work to start an
> RTEMS application in the 32bit compatibility mode?

32bit mode should run.

Chris