Initial commit

1 files changed, 37 insertions, 0 deletions

diff --git a/unix/as.mc68020/zsvjmp.s b/unix/as.mc68020/zsvjmp.s
new file mode 100644
index 00000000..efebe43e
--- /dev/null
+++ b/unix/as.mc68020/zsvjmp.s
@@ -0,0 +1,37 @@
+|# ZSVJMP, ZDOJMP -- Set up a jump (non-local goto) by saving the processor
+|# registers in the buffer jmpbuf.  A subsequent call to ZDOJMP restores
+|# the registers, effecting a call in the context of the procedure which
+|# originally called ZSVJMP, but with the new status code.  These are Fortran
+|# callable procedures.
+|#
+|# (SUN/UNIX MC68xxx version)
+ 
+        .text
+        .globl  _zsvjmp_
+
+	|# The following has nothing to do with ZSVJMP, and is included here
+	|# only because this assembler module is loaded with every process.
+	|# This code sets the value of the symbol MEM (the Mem common) to zero,
+	|# setting the origin for IRAF pointers to zero rather than some
+	|# arbitrary value, and ensuring that the MEM common is aligned for
+	|# all datatypes as well as page aligned.  A further advantage is that
+	|# references to NULL pointers will cause a memory violation.
+
+	.globl	_mem_
+	_mem_	=	0
+
+        JMPBUF	=       4
+        STATUS  =       8
+
+	|# The strategy here is to build on the services provided by the C
+	|# setjmp/longjmp.  Note that we cannot do this by writing a C function
+	|# which calls setjmp, because the procedure which calls setjmp cannot
+	|# return before the longjmp is executed.
+
+_zsvjmp_:	|# CALL ZSVJMP (JMPBUF, STATUS)
+        movl    sp@(JMPBUF),a0          |# set A0 to point to jmp_buf 
+        movl    sp@(STATUS),a1          |# A1 = status variable 
+        movl    a1,a0@			|# JB[0] = addr of status variable
+	clrl	a1@			|# return zero status
+	addql	#4,sp@(JMPBUF)		|# skip first cell of jmp_buf
+        jmp     _setjmp			|# let setjmp do the rest.