From Lucho with some help from Tom: initialize serial ports and retry

serial reads on timeout.


git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@725 6ac86273-5f31-0410-b378-82cca8765d1b

kernel/main.c

@@ -53,6 +53,7 @@ STATIC VOID signon(VOID);
 STATIC VOID kernel(VOID);
 STATIC VOID FsConfig(VOID);
 STATIC VOID InitPrinters(VOID);
+STATIC VOID InitSerialPorts(VOID);
 STATIC void CheckContinueBootFromHarddisk(void);
 
 #ifdef _MSC_VER
@@ -202,6 +203,7 @@ STATIC void init_kernel(void)
   /* Initialize IO subsystem                                      */
   InitIO();
   InitPrinters();
+  InitSerialPorts();
 
   /* set interrupt vectors                                        */
   setvec(0x1b, got_cbreak);
@@ -616,6 +618,23 @@ STATIC VOID InitPrinters(VOID)
   }
 }
 
+STATIC VOID InitSerialPorts(VOID)
+{
+  iregs r;
+  int serial_ports, i;
+
+  init_call_intr(0x11, &r);     /* get equipment list */
+
+  serial_ports = (r.a.x >> 9) & 7;      /* bits 11-9 */
+
+  for (i = 0; i < serial_ports; i++)
+  {
+    r.a.x = 0xA3;               /* initialize serial port to 2400,n,8,1 */
+    r.d.x = i;
+    init_call_intr(0x14, &r);
+  }
+}
+
 /*****************************************************************
 	if kernel.config.BootHarddiskSeconds is set,
 	the default is to boot from harddisk, because

kernel/serial.asm

@@ -61,6 +61,8 @@ ComRead:
                 jnz     ComRd2
 ComRd1:
                 call    BiosRdCom
+                or      ah,ah   ; timeout?
+                js      ComRd1  ; yes, try again
 ComRd2:
                 stosb
                 loop    ComRd1