X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f From: Eph Newsgroups: comp.os.msdos.djgpp Subject: Re: calling a RM function which is placed below 1 MB Date: Thu, 24 Jul 2008 01:30:36 -0700 (PDT) Organization: http://groups.google.com Lines: 75 Message-ID: References: NNTP-Posting-Host: 80.70.169.36 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 X-Trace: posting.google.com 1216888237 10550 127.0.0.1 (24 Jul 2008 08:30:37 GMT) X-Complaints-To: groups-abuse AT google DOT com NNTP-Posting-Date: Thu, 24 Jul 2008 08:30:37 +0000 (UTC) Complaints-To: groups-abuse AT google DOT com Injection-Info: b1g2000hsg.googlegroups.com; posting-host=80.70.169.36; posting-account=jZZPxgoAAAAqQ_zmNV7SH4j6l4lfRyOd User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.9.0.1) Gecko/2008070208 Firefox/3.0.1,gzip(gfe),gzip(gfe) X-HTTP-Via: 1.1 abgpro01 (NetCache NetApp/6.0.6) To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by delorie.com id m6O8j2jo024178 Reply-To: djgpp AT delorie DOT com Thx for your hint. I thought: memset(®s, 0, sizeof(__dpmi_regs)); Zeros it all so this should not matter isn't it? Ciao Ephraim On 23 Jul., 20:45, "Rod Pemberton" wrote: > "Eph" wrote in message > > news:ca0df607-1be3-4358-b84f-f0ccddde3197 AT d77g2000hsb DOT googlegroups DOT com... > > > > > I've problems to get a call to > > __dpmi_simulate_real_mode_procedure_retf_stack working correctly. > > My problem is, that I need to call a 16Bit real Mode function placed > > in Memory below 1MB, which expects three parameters to be placed on > > the RM Stack.(see comments in the code). > > > Below the code, how I tried to use the function: > > > --------------- > > __dpmi_regs regs; > > struct { > > unsigned long u1; > > unsigned long u2; > > unsigned long u3; > > } stack; > > > memset(&stack, 0, sizeof(stack)); > > > stack.u1 = parm1; // expected at bp[14] > > stack.u2 = parm2; // expected at bp[10] > > stack.u3 = parm3; // expected at bp[06] > > > memset(®s, 0, sizeof(__dpmi_regs)); > > > regs.x.cs = seg; // segment of the function entry > > regs.x.ip = ofs; // offset of the function entry > > DPMI 0.9 says ss:sp must be zero for the DPMI host to provide a real mode > stack, or ss:sp must point to a valid real mode stack.  DJGPP doc's > (libc.info) say ss:sp and flags must be set to valid values or zero. > > regs.x.ss=0; > regs.x.sp=0; > > The DJGPP doc's don't state which "flags" must be set (DPMI or __dpmi_regs): > > regs.x.flags=0; /* __dpmi_regs  flags */ > regs.h.bh=0; /* DPMI flags */ > > But, it's likely the doc's were referring to the DPMI flags...  (BH bit 0 = > 1 resets A20 and PIC)  You'll also need to set any other registers that the > function uses since the call copies _all_ registers. > > > __dpmi_simulate_real_mode_procedure_retf_stack(®s, sizeof(stack) / > > 2, &stack); > > --------------- > > > What am I doing wrong? > > Not sure. > > > Can anyone please point it out! > > Try the above.  Let us know. > > Rod Pemberton