Port-sparc archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: Anyone have working pre-v8 machines?

>> v7/post-v7 can be tested by trying to use a hardware multiplication
>> instruction; if it causes an illegal instruction error, it's v7 (...
>> unless the OS traps and emulates it but I don't think NetBSD or any
>> Sun OSes do that), otherwise it's v8 or newer.

Well, looking at NetBSD/sparc 1.4T trap.c, I see

        case T_ILLINST:
        case T_UNIMPLFLUSH:
                if ((n = emulinstr(pc, tf)) == 0) {
                trapsignal(p, n, 0);    /* XXX code?? */

and then emulinst(), in emul.c, handles only certain instructions; I
haven't worked out exactly which ones, but it does call something
called muldiv(), which is commented

         * We check for {S,U}{MUL,DIV}{,cc}
         * [c = condition code, s = sign]
         * Mul = 0c101s
         * Div = 0c111s

and it looks to me as though it _tries_ to handle multiplication.  So I
suspect NetBSD might well handle it.

I certainly could build a kernel that doesn't, though, or I could print
something when that code runs, or some such.

/~\ The ASCII				  Mouse
\ / Ribbon Campaign
 X  Against HTML		mouse%rodents-montreal.org@localhost
/ \ Email!	     7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B

Home | Main Index | Thread Index | Old Index