From 2f62d5544d13ca32dc09504ec70358db581e9e65 Mon Sep 17 00:00:00 2001
From: Christos Zoulas <christos@zoulas.com>
Date: Wed, 31 Mar 2021 19:51:14 +0000
Subject: [PATCH] Improve 8086 relocatable detection (Joerg Jenderek)

---
 magic/Magdir/xenix | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/magic/Magdir/xenix b/magic/Magdir/xenix
index 3e248de26..d5ab69e5d 100644
--- a/magic/Magdir/xenix
+++ b/magic/Magdir/xenix
@@ -1,6 +1,6 @@
 
 #------------------------------------------------------------------------------
-# $File: xenix,v 1.12 2021/02/23 00:51:10 christos Exp $
+# $File: xenix,v 1.13 2021/03/31 19:51:14 christos Exp $
 # xenix:  file(1) magic for Microsoft Xenix
 #
 # "Middle model" stuff, and "Xenix 8086 relocatable or 80286 small
@@ -13,25 +13,35 @@
 #
 0	string		core		core file (Xenix)
 # URL: http://www.polarhome.com/service/man/?qf=86rel&tf=2&of=Xenix
+#      http://fileformats.archiveteam.org/wiki/OMF
 # Reference: http://www.azillionmonkeys.com/qed/Omfg.pdf
 # Update: Joerg Jenderek
 # recordtype~TranslatorHEADerRecord
 0	byte		0x80
-# GRR: line above is too general as it catches also Extensible storage engine DataBase
+# GRR: line above is too general as it catches also Extensible storage engine DataBase,
+# all lif files like forth.lif hpcc88.lif lex90b.lif ( See ./lif)
+# and all compressed DEGAS low-res bitmaps like: MUNCHIE.PC1 PIDER1.PC1
 # skip examples like GENA.SND Switch.Snd by looking for record length maximal 1024-3
 >1	uleshort	<1022
 # skip examples like GAME.PICTURE Strange.Pic by looking for positive record length
 >>1	uleshort	>0
 # skip examples like Xtable.Data FRACTAL.GEN SHR.VIEW by looking for positive string length
 >>>3	ubyte		>0
-# skip examples like OMBRE.6 with "UUUUUU" by looking for filename like "hello.c"
->>>>4	regex	[a-zA-Z_/]{1,8}[.]	8086 relocatable (Microsoft)
+# skip examples like OMBRE.6 with "UUUUUU" name by looking for valid high second record type
+>>>>(1.s+3)	ubyte	>0x6D	8086 relocatable (Microsoft)
 #!:mime	application/octet-stream
 !:mime	application/x-object
-!:ext	o/a
+!:ext	obj/o/a
+# T-module name often source name like "hello.c" or "jmppm32.asm" in JMPPM32.OBJ or
+# "kbhit" in KBHITS.OBJ or "CAUSEWAY_KERNAL" in CWAPI.OBJ
 >>>>>3	pstring		x		\b, "%s"
+# data length probably lower 256 according to TrID obj_omf.trid.xml
+>>>>>1	uleshort	x		\b, 1st record data length %u
 # checksum
 #>>>>>(3.b+4)	ubyte	x		\b, checksum 0x%2.2x
+# second recordtype: 96h~LNAMES 88h~COMENT 8CH~EXTDEF
+>>>>>(1.s+3)	ubyte	x		\b, 2nd record type 0x%x
+>>>>>(1.s+4)	uleshort x		\b, 2nd record data length %u
 0	leshort		0xff65		x.out
 >2	string		__.SYMDEF	 randomized
 >0	byte		x		archive