sms@wlv.imsd.contel.com (Steven M. Schultz) (08/23/89)
Subject: 'as' doesn't recognize the no-op instruction
Index: bin/as 2.10BSD
Description:
the assembler 'as' doesn't recognize (yet another) instruction,
the "nop" (no-operation). This created a problem when recompiling
the standalone system because some of the boot programs require
a 'nop' as the first word.
Repeat-By:
cd /tmp
ed x.s
a
nop
w
q
/bin/as x.s
observe the error.
Fix:
Somewhere along the way, the 'nop' handling either didn't make
it in to the distribution OR the 'nop' pseudo-define was removed
from pdp/DEFS.h. IN ANY EVENT, an assembler should support ALL
the instructions of the processor it runs on (should also be
able to run split I/D and/or shared text, but i haven't gotten
carried away enough yet), this is a small attempt to move in
that direction.
Apply the following patches to bin/as/{as19.s,as29.s} to implment
'nop'.
*** as19.s.old Fri Jan 22 07:06:51 1988
--- as19.s Tue Aug 22 17:12:08 1989
***************
*** 184,189 ****
--- 184,190 ----
/ flag-setting
+ <nop\0\0\0\0\0>; 01;0000240
<clc\0\0\0\0\0>; 01;0000241
<clv\0\0\0\0\0>; 01;0000242
<clz\0\0\0\0\0>; 01;0000244
*** as29.s.old Fri Jan 22 07:28:05 1988
--- as29.s Tue Aug 22 17:12:29 1989
***************
*** 151,156 ****
--- 151,157 ----
/ flag-setting
+ 01;0000240 /nop
01;0000241 /clc
01;0000242 /clv
01;0000244 /clz