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 > > >
