Initial revision

mach/m68020/libsys/head_em.s

@@ -0,0 +1,71 @@
+.define .lino,.filn
+.define EXIT
+.define	begtext,begdata,begbss
+.define	EARRAY,ERANGE,ESET,EIDIVZ,EHEAP,EILLINS,ECASE,EBADGTO
+.define	hol0,.reghp,.limhp,.trpim,.trppc
+.sect .text
+.sect .rom
+.sect .data
+.sect .bss
+
+
+
+! runtime startof for 68020 machine
+
+
+LINO_AD	= 0
+FILN_AD	= 4
+
+EARRAY	= 0
+ERANGE	= 1
+ESET	= 2
+EIDIVZ	= 6
+EHEAP	= 17
+EILLINS	= 18
+ECASE	= 20
+EBADGTO = 27
+
+	.sect .text
+begtext:
+	move.l	d0,(splimit)	! load splimit with the initial stack limit
+	sub.l	#8,sp
+	move.l	(8,sp),(sp)	! argc
+	lea	(12,sp),a0
+	move.l	a0,(4,sp)	! argv
+	move.l	a0,a1
+1:
+	tst.l	(a0)+		! null args term?
+	bne	1b
+	cmp.l	(a1),a0		! end of 'argv[]' and in *argv[] strings?
+	blt	2f		! skip if a0 is less than start of *argv[]
+	sub.l	#4,a0		! else backup one to set env = 0 (NULL)
+2:
+	move.l	a0,(8,sp)	! env
+!	move.l	a0, environ	! indir is 0 if no env; not 0 if env
+!	jsr	(initfpu)	! call to dummy floating point init routine
+	jsr	(_m_a_i_n)
+	move.l	d0,(sp)		! no stack cleanup needed
+EXIT:
+	jsr	(__exit)
+
+	.sect .data
+begdata:
+splimit:
+	.data4 0		! may be at virtual address 0 with no problem
+hol0:
+.lino:
+	.data4	0	! lino
+.filn:
+	.data4	0	! filn
+.reghp:
+	.data4	endbss
+.limhp:
+	.data4	endbss
+.trppc:
+	.data4	0
+.trpim:
+	.data4	0	! USED TO BE 2 BYTES; IS THIS RIGHT?
+
+
+	.sect .bss
+begbss: !initialization is not needed because ALL entries are in zero space!