Hi,
SDCC recently added a 6502 port, based on their HC08 port. I think it
has a chance to be better than cc65 or any gcc arsenal.
Yes, the 6502 8-bit hardware stack is very limited, but by paying the
price of a less efficient code, a software stack is possible.
Of course, such a port would probably be EXTREMELY limited and possiby
just a proof of concept, but a fun one for sure.
Speaking of the Z80, would it be possible to run NuttX in a Grant Searle
/ RC2014 platform with a 8k ROM /56k RAM split, or would any attempt
require banked memory?
I appreciate this discussion about protecting the NuttX supported platforms.
So many RTOS are just for arm.
Sebastien
Le 08/01/2022 à 15:46, Alan Carvalho de Assis a écrit :
Yes, now I remember the reason to it has been removed.
BTW, I think 6502 will face same issue because the stack point is only
8-bits (it will be limited to 256 bytes), correct?
On 1/8/22, Gregory Nutt <spudan...@gmail.com> wrote:
Support for the 8051 was removed for other reasons... that family has a
very small hardware stack that had to be saved and restored on each context
switch. That provided bigtime compatibility issues with other
architectures. That combined with the facts that (1) I never could get the
8051 running reliably without stack overflows, and (2) the 8051 was not
really a viable platform for NuttX because it was so limited in other ways.
That is ancient history from 2014. I used to carefully document why any
feature was removed from the OS and kept that here:
https://bitbucket.org/patacongo/obsoleted/src/60ec01456d8b09f5b813a5fd8865cdbd5a0ccc20/ChangeLog#lines-4
On Sat, Jan 8, 2022 at 7:45 AM Alan Carvalho de Assis <acas...@gmail.com>
wrote:
Hi Tomasz,
Currently NuttX doesn't support 6502 and even the support to 8051 was
removed some years ago.
BTW, I think it could be possible to support C99 for 6502 if you use gcc:
https://github.com/itszor/gcc-6502-bits
BR,
Alan
On 1/8/22, Tomasz CEDRO <to...@cedro.info> wrote:
On Sat, Jan 8, 2022 at 1:53 PM Gregory Nutt wrote:
z80 holds all 8-bit ZiLOG architectures. That means
z80 using the SDCC compiler
z180 using the SDCC compiler
ez80 which normally uses the ZiLOG compiler, but there is an
experimental
version of GCC for the ez80
z16 uses only ZiLOG compiler
Also consider SH1
This will also require changes to INVIOLABLES.md and the coding
standard.
I would also recommend a formal vote to assure that you are following
the
will of the user base and not a personal agenda. There used to be a
small
but important group of retro computer folk using NuttX; this
eliminates
support for them. There is language in the INVIOLABLES that is there
specifically to protect them from actions like this.
I have not heard of anyone using these architectures recently. I
would
say
that only ez80 is active with active development boards. There are
occasional developments with z180-like hardware.
One day I would love to run NuttX on 6502.. it would be nice if C99
wont make it impossible (why should it?).. but my knowledge is too
small so I will look how the thread goes :-)
--
CeDeROM, SQ7MHZ, http://www.tomek.cedro.info
