[GSoC - x86_64] Console / serial communication

[Amaan Cheval]

Hi!

Quick question since the BSP guide is outdated - I see several
"methods" of RTEMS' console management. The guide says to use
console-termios.c (and rtems_termios_device_install) as the "new"
method.
https://docs.rtems.org/branches/master/bsp-howto/console.html#build-system-and-files

Most BSPs (beagle, pc386, malta) using NS16550 use legacy-console.c,
though - are NS16550 and Termios mutually exclusive for now?

Or is it simply that none of the old NS16550 users have been ported
over to using console-termios.c as well?

What would be the expectation from a new BSP?

On Tue, Jun 26, 2018 at 12:42 PM, Amaan Cheval <amaan.cheval at gmail.com> wrote:
> On Tue, Jun 26, 2018 at 12:15 PM, Chris Johns <chrisj at rtems.org> wrote:
>> On 26/06/2018 14:29, Amaan Cheval wrote:
>>> On Tue, Jun 26, 2018 at 4:10 AM, Chris Johns <chrisj at rtems.org> wrote:
>>>> On 25/06/2018 21:40, Amaan Cheval wrote:
>>>>
>>>> Will a text based video console be supported?
>>>
>>> As above, I can't say :P
>>> The only guiding factor I have for GSoC is to do the _minimal_ needed
>>> port first, because the project is quite wide - once _all_ the basics
>>> (clock next, some of IRQ, maybe ACPI) are done, we can look into what
>>> to improve further if we have the time.
>>
>> Sure this is best approach.
>>
>>> Given the possibility that we may not be able to add more than one
>>> console this summer, which would we want the most? Which driver? (I'm
>>> trying to do my own research too, of course, but if there's an obvious
>>> one you can think of, let me know!)
>>
>> Lets see how the serial UART goes first.
>
> Cool.
>
> Just as a note for the future: loader.efi does seem to set some EFI
> framebuffer (efifb) work up - I suspect it's similar to how some
> bootinfo is passed to the kernel
> (http://fxr.watson.org/fxr/source/i386/include/bootinfo.h?v=FREEBSD11#L48).
> This is worth investigating later for:
> - Seeing how the ELF kernel detects memory info
> - How to access the UEFI UGA/GOP graphics APIs
> - Accessing UEFI's RuntimeServices (most of them seem unnecessary, but
> ResetSystem may be usefu in lieu of ACPI work)
>
> For now I'm just focusing on the UART work, and then hopefully we can
> get hello.exe passing and get the minimal BSP upstreamed after major
> cleanups (- if the UART work takes too long, I believe we ought to
> clean up and merge _some_ before phase 2 regardless).
>
>>
>>>
>>> I only picked UART because it seems to be what's used when we use
>>> QEMU's "-serial stdio" flags.
>>>
>>
>> This is a good option and I often use it on a PC.
>>
>> Chris