[Scst-devel] Porting a driver from FreeBSD CAM to SCST

[Hein-Pieter v. B. <hp...@tm...>]

Hello all!



I've been interested in running SCST as a PSCSI target. After a lot of reading it seems that right now it is no longer possible to do so. I happen to have several AIC7980 based controllers that I'd like to use for this purpose.



I've done some comparisons between the FreeBSD aic7xxx driver and the Linux one, and they are still fairly similar. I have also found a copy of Hu/Steve Gang's aic7xxx initial port to SCST, but that one appears to be very limited in what it can do.



So, I think to make this happen I'll have to do some driver surgery :) Which I'm happy to do but I was wondering if perhaps there was some kind of documentation or perhaps someone here has some tips on how to "map" FreeBSD CAM target functionality to SCST. I've been looking at the various entry points for SCST and I think I understand what they are for, but it appears that CAM is a bit more ... integrated into the drivers than SCST is, and it is a little hard for me to work out what really does what. Particularly the int (*rdy_to_xfer)(struct scst_cmd *cmd) is difficult to find a CAM equivalent for, or I'm just entirely misunderstanding what it is supposed to do.



Any help would be much appreciated!



Also, yes, I'm aware it is 2024. I have reasons ;) possibly poor ones. But here we are.



- HP