On Tue, 2008-08-19 at 17:16 +0000, michealbutz2002 wrote:
> I am a an Assembler internals Guy and am trying to expand my
> horizons
>
> I am trying to display MVS info e.g. some of the things in HSCCMD.C
>
> In a GUI front I did a Windows API CreateProcess to Create a Window
> 32 WinMain app to display info displayed in DOS box from hsccmd.c
>
>
> you have given me some idea of what I need to do
>
> let me see if this can help
What Roger said. Stuff in mainstor is big-endian. Stuff in control
blocks is usually host-endian (little-endian on intel). You should
always know how many bytes you are fetching from mainstor (whereas on
host you don't know if `void *ptr' is 4, 8 or some other number of
bytes).
To do virtual addressing, you should use the MADDR macro. The control
regs (2 (primary) or 7 (secondary) or 13 (home) or etc) must be set up.
The virtual address should probably be resolvable to a real address else
you are going to take a page interrupt.
Below is some code I wrote a while back that fits into an instruction.
Bonus points to anyone that can explain what it does ;-)
Extra bonus points if you can explain why this code shows you cannot
necessarily trust your hardware vendor.
Greg
--- hercules-cvs/general2.c 2007-01-13 02:21:48.000000000 -0500
+++ hercules/general2.c 2007-02-04 13:03:06.000000000 -0500
@@ -1373,6 +1373,24 @@
}
#endif
+ if (i == 131 && sysblk.stepaddr[0] == 131)
+ {
+ BYTE *mn = NULL;
+ ARCH_DEP(display_inst)(regs, inst);
+ if (regs->GR_L(1))
+ mn = MADDR(regs->GR_L(1),0,regs,ACCTYPE_READ,0);
+ else if (regs->GR_L(0))
+ {
+ VADR p;
+ p = fetch_fw(MADDR(regs->GR_L(0)+4,0,regs,ACCTYPE_READ,0)); // SAFP
+ if (p && fetch_hw(MADDR(p+0x0c,0,regs,ACCTYPE_READ,0)) == 0x0005)
+ mn = MADDR(p + fetch_hw(MADDR(p+0x08,0,regs,ACCTYPE_READ,0)),
+ 0,regs,ACCTYPE_READ,0);
+ }
+ if (mn && (mn[3] & 0x80) == 0x00)
+ mn[3] |= 0x08;
+ }
+
/* Point to PSA in main storage */
psa = (void*)(regs->mainstor + px);
