Extern Lib with asm in neo geo dev kit - Page 1

Hi again,

I am using the neo geo dev kit of Neothunder
Using the same model as libvideo.c (and video.s) i am coding some tools asm routs

Guys, can you tell me if you always save context before entering the asm rout or not ?
In the neothunder kit i found an helper.s with a SAVECONTEXT and RESTORECONTEXT to do it.

What hapenning if a register is used by the code ?
I call the asm rout from my .c code ... so how can i be sure that D0 register for instance is not used ?
D0 register is always used for the return of the asm rout ?

Thanks in advance

For 68000, D0 D1 A0 A1 are considered scratch registers, so you don"t have to save thoses 4.

If you need more you have to save/restore them in your code.

Thanks i forgot theses ones
Men, this forum is very helpful