Initial revision

diff --git a/mach/m68020/libsys/head_em.s b/mach/m68020/libsys/head_em.s
new file mode 100644 (file)
index 0000000..f69fdb8
--- /dev/null
+++ b/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!