Re: [Amforth] A RISC-V update

[Keith A. <ca...@pi...>]

Thanks for the update! Both the board and the experimental AmForth-RV 
implementation look really interesting. I'm curious how you're planning 
to use the compiled C object support. I can see that being helpful to 
access existing high-level building blocks for things like USB. Is it 
possible to give a walk-through of how it works?

Cheers!  Keith

On 2/6/24 02:23, ho...@tj... wrote:
> A risc-v update.
>
> AmForth-RV update
>
> Good progress made with the CH32V307 [0]
>
> Words defined in the RAM dictionary can now be appended to the FLASH
> dictionary so user defined words (individual words or the entire RAM
> dictionary) are able to survive a reset. This was one of my major
> milestones and (in my mind) a requirement for a self-hosted Forth. I
> was not able to achieve this with the FE310 based red v board.
>
> Additionally, something new to AmForth. Compiled C objects can be linked
> into AmForth-RV and called from within CODEWORDs. This is a build
> level modification and arguments are passed to the C function using
> assembly according to the risc-v calling convention.
>
> The CH32V307 makes a very good target mcu for AmForth-RV and for
> experimenting with embedded RISC-V in general.
>
> - The development board is inexpensive and available [1] [2]
> - There is official documentation and many 3rd party resources
> - The mcu can program its own flash whilst executing from flash
> - AmForth-RV can be built with an open source toolchain (build in < 
> 3s, flash in < 6s )
>
> If you are interested in trying some risc-v hardware I think it is a
> good choice.
>
> AmForth-RV is still experimental, but has made a step in the direction
> of being less so. There are quite a few decisions to be made, so any
> thoughts on what AmForth-RV might look like in the future are very 
> much welcomed.
>
> Best wishes,
> Tristan
>
> [0] https://github.com/openwch/ch32v307
> [1] https://wchofficialstore.aliexpress.com/store/1100367542
> [2] https://www.aliexpress.com/item/1005004329125620.html
> (and many other suppliers)
>
> A brief annotated/edited session showing saving a RAM dictionary word.
>
> // see if a word 3+ has been defined //
>
>  ok
>> show 3+
> LFA..... (LFA)... FFA..... (FFA)... NFA..... XT...... (XT).... word....
>  ok
>
> // no it has not, so define it in the RAM dictionary //
>
>> : 3+ 1+ 1+ 1+ ;
>  ok
>
> // and see that it exists //
>
>> show 3+
> LFA..... (LFA)... FFA..... (FFA)... NFA..... XT...... (XT).... word....
> 20003A54 200039B4 20003A58 00000000 20003A5C 20003A60 COLON    3+ (in 
> RAM)
>  ok
>
> // now append the word 3+ to the FLASH dictionary //
>
>> save 3+
> 3+ HHHHBBBB 3+
>  ok
>
> // and see that it exists //
>
>> show 3+
> LFA..... (LFA)... FFA..... (FFA)... NFA..... XT...... (XT).... word....
> 0000D200 0000D094 0000D204 00000000 0000D208 0000D20C COLON    3+ (in 
> FLASH)
> 20003A54 200039B4 20003A58 00000000 20003A5C 20003A60 COLON    3+ (in 
> ROM)
>  ok
>
> // it does, twice, once in RAM and once in FLASH //
>
> // reset the board //
>
> AmForth-RV 7.0 RV32IMAFC WCH CH32V307
> Fri 19 Jan 2024 16:46:34 GMT
>
> // see if 3+ exists //
>
>> words
> 3+ forth-wordlist environment riscv-wordlist @cycle type0
> hifive-turnkey rev-info build-info mtimecmp mtime led.init -led +led
>> forth-wordlist >flash.p ram>flash flash>ram ram>rom rom>ram
>
> // see if it works //
>
>> 100 3+
>  ok
>> u.
> 103  ok
>>
>
>
> _______________________________________________
> Amforth-devel mailing list for http://amforth.sf.net/
> Amf...@li...
> https://lists.sourceforge.net/lists/listinfo/amforth-devel
>