P2 Taqoz V2.8: Calling a Forth Word from Assembler Code
Christof Eb.
Posts: 1,173
Hi,
perhaps this might be useful for others...
The idea is to be able to call a Forth Word from inside a code word. Of course you must be careful, that your register variables might get overwritten by the Forth code. While it is easy to call the Forth word, some effort must be done to enable correct return to the calling routine. - If anyone has a more elegant way to do it, feel free to post it...
484 := wPointer \ store for the Instruction word Pointer $31 := doNext : prtHello \ do something crlf ." Hello" ." from Forth" crlf \ return to assembler SUB: mov PTRA,wPointer ' \ return from Forth restore IP pop r1 ' \ discard one return level ret FORTH: ." never reached " ; ' prtHello := aPrtHello \ get start address code cTest ( x -- x+6 ) ' \ calls a Forth word add a,#1 mov wPointer,PTRA ' \ save IP mov PTRA,##aPrtHello call #doNext add a,#5 ret end : cT 1 cTest . \ use the code word ;
Have Fun! Christof