pc386 hello.exe on real hardware (issues with VGA/VBE output)

[Karel Gardas]

On 8/26/20 9:53 AM, Chris Johns wrote:

>> I'm not able to run hello.exe on real
>> hardware PC w/o UART1 presented/connected and get its expected "Hello"
>> output to the VGA/GPU console. I think RTEMS still pushed hello message
>> down to the UART1.
> 
> I just want to understand what UART1 is. Is it COM1?
>

Yes, UART1 means COM1 here.

Anyway, I must admit I've had some bad-luck here. I've tested or started
by testing on two old ThinkPads available here: T500 and T400 and today
I've just found out those are RTEMS-broken machines. Today I've widened
my testing and tested:

ASRock B450/Ryzen 3600/16GB:
- hello.exe -- WORKS
- ticker.exe -- WORKS
- hello.exe SMP -- BROKEN
- ticker.exe SMP -- BROKEN

Supermicro X9SRA/Xeon E5-2620/64GB:
- hello.exe -- WORKS
- ticker.exe -- WORKS
- hello.exe SMP -- BROKEN
- ticker.exe SMP -- BROKEN

IBM ThinkPad T22/PIII/512MB:
- hello.exe -- WORKS
- ticker.exe -- WORKS
- hello.exe SMP -- BROKEN
- ticker.exe SMP -- BROKEN

Fujitsu/Kontron D3598-B1x/Xeon W-2265/128GB:
- hello.exe -- WORKS
- ticker.exe -- WORKS
- hello.exe SMP -- WORKS (* note: number of CPUs reported is number of
cores available, HT is misdetected/not-supported by RTEMS)
- ticker.exe SMP -- WORKS (* note: like above)

And T400/T500:
- hello.exe -- BROKEN
- ticker.exe -- BROKEN
- hello.exe SMP -- BROKEN
- ticker.exe SMP -- BROKEN


So as you can see, a bit of bad luck. Also generally speaking SMP
enabled pc386 is a bit fragile since it works only on Kontron/Fujitsu
(as HW) and then only in Qemu -- and up to just 16 number of CPUs -- in
Qemu. I don't have hardware available with more CPUs and my W-2265 with
HT enabled gives 24 virtual cores, but RTEMS still sees just 12 real
cores -- see note above.


So this way I continue with my pc386 docs tweaks...

Karel

PS: T22 above is the same machine as reported working here:
https://devel.rtems.org/wiki/TBR/BSP/Pc386 -- note from September 1 2005.