The S24/TCX datasheet is listed as "Unable to locate" on [1]. However the NetBSD revision 1.32 of the driver introduced 64-bit accesses to the stippler and blitter [2]. It is safe to assume these memory regions are 64-bit accessible. QEMU implementation is 32-bit, so fill the 'impl' fields. Michael Lorenz (author of the NetBSD code [2]) provided us with more information in [3]: > IIRC the real hardware *requires* 64bit accesses for stipple and > blitter operations to work. For stipples you write a 64bit word into > STIP space, the address defines where in the framebuffer you want to > draw, the data contain a 32bit bitmask, foreground colour and a ROP. > BLIT space works similarly, the 64bit word contains an offset were to > read pixels from, and how many you want to copy. > > One more thing since there seems to be some confusion - 64bit accesses > on the framebuffer are fine as well. TCX/S24 is *not* an SBus device, > even though its node says it is. > S24 is a card that plugs into a special slot on the SS5 mainboard, > which is shared with an SBus slot and looks a lot like a horizontal > UPA slot. Both S24 and TCX are accessed through the Micro/TurboSPARC's > AFX bus which is 64bit wide and intended for graphics. > Early FFB docs even mentioned connecting to both AFX and UPA, > no idea if that was ever realized in hardware though. [1] http://web.archive.org/web/20111209011516/http://wikis.sun.com/display/FOSSdocs/Home [2] http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/dev/sbus/tcx.c.diff?r1=1.31&r2=1.32 [3] https://