From 1b1101e52fb2e5aee77fd2243c9cd45d9635213d Mon Sep 17 00:00:00 2001
From: Warner Losh <imp@FreeBSD.org>
Date: Fri, 17 Jul 1998 00:18:52 +0000
Subject: [PATCH] o for unknown int21 functions, set the CY bit to indicate
 failure o When reporting a int21 function we don't know about yet, report  
 AH as the major and AL as the minor, as opposed to reporting AL   as the
 major. o Add support for 21:44:7: ioctl check output status.  We  
 optimistically say that output is always ready. o Add half support for 21:23:
 get file size.  We always now return   failure.  This function isn't
 supported, according to the interrupt   list, by the DOS box in windows, so I
 don't feel too bad.

---
 usr.bin/doscmd/dos.c | 36 ++++++++++++++++++++++++++++++++++--
 1 file changed, 34 insertions(+), 2 deletions(-)

diff --git a/usr.bin/doscmd/dos.c b/usr.bin/doscmd/dos.c
index aada188b0716..b81330483f18 100644
--- a/usr.bin/doscmd/dos.c
+++ b/usr.bin/doscmd/dos.c
@@ -31,7 +31,7 @@
  *
  *	BSDI int21.c,v 2.2 1996/04/08 19:32:51 bostic Exp
  *
- * $Id: dos.c,v 1.3 1998/07/02 05:12:52 imp Exp $
+ * $Id: dos.c,v 1.4 1998/07/16 23:54:23 imp Exp $
  */
 
 #include "doscmd.h"
@@ -707,6 +707,21 @@ int21_1a(regcontext_t *REGS)
     return(0);
 }
 
+/*
+** 21:23
+**
+** Get file size for fcb
+** DS:DX -> unopened FCB, no wildcards.
+** pcb random record field filled in with number of records, rounded up.
+*/
+static int
+int21_23(regcontext_t *REGS)
+{
+    debug(D_HALF, "Returning failure from get file size for fcb 21:23\n");
+    R_AL = 0xff;
+    return(0);
+}
+
 /*
 ** 21:25
 **
@@ -1474,6 +1489,19 @@ int21_44_1(regcontext_t *REGS)
     return(0);
 }
 
+/*
+** 21:44:7
+**
+** Get output status
+*/
+static int
+int21_44_7(regcontext_t *REGS)
+{
+    /* XXX Should really check to see if BX is open or not */
+    R_AX = 0xFF;
+    return(0);
+}
+
 /*
 ** 21:44:8
 **
@@ -2276,6 +2304,7 @@ static struct intfunc_table int21_table [] = {
     { 0x1b,	IFT_NOSUBFUNC,	int21_free,	"get allocation for default drive"},
     { 0x1c,	IFT_NOSUBFUNC,	int21_free,	"get allocation for specific drive"},
     { 0x1f,	IFT_NOSUBFUNC,	int21_NOFUNC,	"get DPB for current drive"},
+    { 0x23,	IFT_NOSUBFUNC,	int21_23,	"Get file size (old)"},
     { 0x25,	IFT_NOSUBFUNC,	int21_25,	"set interrupt vector"},
     { 0x26,	IFT_NOSUBFUNC,	int21_26,	"create new PSP"},
     { 0x2a,	IFT_NOSUBFUNC,	int21_2a,	"get date"},
@@ -2308,6 +2337,7 @@ static struct intfunc_table int21_table [] = {
     { 0x43,	IFT_NOSUBFUNC,	int21_43,	"get/set file attributes"},
     { 0x44,	0x00,		int21_44_0,	"ioctl(get)"},
     { 0x44,	0x01,		int21_44_1,	"ioctl(set)"},
+    { 0x44,	0x07,		int21_44_7,	"ioctl(Check output status)"},
     { 0x44,	0x08,		int21_44_8,	"ioctl(test removable)"},
     { 0x44,	0x09,		int21_44_9,	"ioctl(test remote)"},
     { 0x45,	IFT_NOSUBFUNC,	int21_45,	"dup"},
@@ -2449,7 +2479,9 @@ int21(regcontext_t *REGS)
     index = intfunc_find(int21_table, int21_fastlookup, R_AH, R_AL);
 
     if (index == -1) {			/* no matching functions */
-	unknown_int2(0x21, R_AL, REGS);
+	unknown_int3(0x21, R_AH, R_AL, REGS);
+	R_FLAGS |= PSL_C;               /* Flag an error */
+        R_AX = 0xff;
 	return;
     }