;***********************************************************************
;  Global Symbol Matcher    BOOT OBJECT
;
;  This function matchs the return address segment AX with the BCO or LCO
;  found in the global symbol table.  If found it returns the print name
;  in DS:AX.  If not, it returns #f.
;
;************************************************************************
   ((el sym.seg #xffda)
    (el sym.off #xffd8)

    (l gsm)
    (push es)
    (push di)
    (push si)
    (push dx)
    (push cx)
    (push bx)

    (mov ax dx)                 ; DX = segment to match
    (ss:) (les (dw w) bx) (aw sym.off)  ; ES:DI = untagged global symbol table
    (xor bh bh)
    (mov bx di)
    (es:) (mov (di db w) cx) 2  ; CX = table size
    (add ib di) 4
;
;  loop over symbol table vector    ES:DI = 1st entry  CX = number
;    
    (l gsm.vloop)
    (push es)
    
    (es:) (les (di w) ax)
    (cmp ib ah) #x11            ; is hash entry a pair?
    (jz) (db gsm.lloop)
    (and ax ax)                 ; is hash entry #f?
    (jnz) (db gsm.error)
    
    (l gsm.vloop.con)
    (pop es)
    (add ib di) 4
    (loop) (db gsm.vloop)
    (xor ax ax)                 ; if not found return #f
    (mov ax ds)
    (jmps) (db gsm.ret)
    
    (l gsm.error)
    (pop es)
    (mov ib dl) 255
    (int #x90)
    
    (l gsm.found)
    (pop es)
    (l gsm.ret)

    (pop bx)
    (pop cx)
    (pop dx)
    (pop si)
    (pop di)
    (pop es)
    (retf)
;
;  loop down one hash entry list ES:AX
;    
    (l gsm.lloop)
    (cmp ib ah) #x01           ; if null then check next hash entry
    (jz) (db gsm.vloop.con)
    (cmp ib ah) #x11           ; if pair then check CAR
    (jz) (db gsm.pck)
    (jmps) (db gsm.error)
    
    (l gsm.pck)
    (xor ah ah)
    (mov ax si)                ; ES:SI = untagged current pair
    (es:) (lds (si w) bx)      ; DS:BX = CAR pair
    (cmp ib bh) #x12
    (jnz) (db gsm.error)
    (xor bh bh)
    (lds (bx w) bx)            ; DS:BX = symbol value
    (cmp ib bh) #x28           ; BCO ?
    (jz) (db gsm.bco.ck)
    (cmp ib bh) #x26           ; closure ?
    (jz) (db gsm.clos.ck)
    
    (l gsm.lloop.con)
    (es:) (les (si db w) ax) 4 ; ES:AX = CDR pair
    (jmps) (db gsm.lloop)
;
;  check BCO for match    
;    
    (l gsm.bco.ck)
    (mov ds ax)
    (cmp dx ax)
    (jnz) (db gsm.lloop.con)
    (es:) (lds (si w) ax)      ; DS:AX = CAR pair
    (jmp) (dw gsm.found)
;
;  check closure's LCO for match    
;    
    (l gsm.clos.ck)
    (xor bh bh)
    (lds (bx db w) ax) 4       ; DS:AX = closure's LCO
    (mov ds ax)
    (cmp dx ax)
    (jnz) (db gsm.lloop.con)
    (es:) (lds (si w) ax)      ; DS:AX = CAR pair
    (jmp) (dw gsm.found)
    
;**************************************************************************
    )