HALised microtime()

Detail:
  microtime(), which reads the current time into a struct timeval (seconds
  and microseconds) looked for an IOMD, and if not then dropped back to
  centisecond accuracy. This hadn't been noticed before, but upon trying the
  module on a 32-bit IOMD build, its attempt to access IOMD at its 26-bit
  address aborted. Now changed to use the HAL if possible, so all HAL machines
  now have a nice accurate microtime().
Admin:
  Tested to the extent that it doesn't abort any more - precise checking of
  microtime() values has not been done, nor any analysis of the effect of
  the increased accuracy.

Version 5.52. Tagged as 'Internet-5_52'

VersionNum

-/* (5.51)
+/* (5.52)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
- * Last processed by srccommit version: 1.2.
+ * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        5.51
+#define Module_MajorVersion_CMHG        5.52
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                24 Feb 2007
+#define Module_Date_CMHG                22 Dec 2008
 
-#define Module_MajorVersion             "5.51"
-#define Module_Version                  551
+#define Module_MajorVersion             "5.52"
+#define Module_Version                  552
 #define Module_MinorVersion             ""
-#define Module_Date                     "24 Feb 2007"
+#define Module_Date                     "22 Dec 2008"
 
-#define Module_ApplicationDate          "24-Feb-07"
+#define Module_ApplicationDate          "22-Dec-08"
 
 #define Module_ComponentName            "Internet"
-#define Module_ComponentPath            "RiscOS/Sources/Networking/AUN/Internet"
+#define Module_ComponentPath            "mixed/RiscOS/Sources/Networking/AUN/Internet"
 
-#define Module_FullVersion              "5.51"
-#define Module_HelpVersion              "5.51 (24 Feb 2007)"
-#define Module_LibraryVersionInfo       "5:51"
+#define Module_FullVersion              "5.52"
+#define Module_HelpVersion              "5.52 (22 Dec 2008)"
+#define Module_LibraryVersionInfo       "5:52"

lib/c/unixenv

@@ -46,6 +46,8 @@
 #include "module.h"
 #include "swiveneers.h"
 
+#include "Global/HALEntries.h"
+
 #define TickerV	 28
 
 #define NCALLOUT 20
@@ -821,23 +823,43 @@ static int iomd_present()
  */
 void microtime(struct timeval *tv)
 {
-    static int iomd_check;  /* 0 = not checked, 1 = present, 2 = not present */
+    static int iomd_check;  /* 0 = not checked, 1 = present, 2 = no counter present, 3 = use HAL */
+    static unsigned long timer_divider; /* ticks per microsecond */
     machinetime t1, t2;
     unsigned long timer_count;
+    unsigned long timer_period = 19999; /* default for non-HAL case */
 
     /* Only poke the hardware if we're sure it's there :) */
     if (!iomd_check)
-        iomd_check = iomd_present();
+    {
+        if (_swix(OS_Hardware, _INR(8,9)|_OUT(0), 0, EntryNo_HAL_CounterRate, &timer_divider) != NULL)
+        {
+            iomd_check = iomd_present();
+            timer_divider = 2;
+        }
+        else
+        {
+            iomd_check = 3;
+            timer_divider /= 1000000;
+            if (timer_divider == 0) timer_divider = 1; /* avoid division by 0 */
+        }
+    }
 
-    if (iomd_check == 1)
+    if (iomd_check != 2)
     {
+        if (iomd_check == 3)
+            _swix(OS_Hardware, _INR(8,9)|_OUT(0), 0, EntryNo_HAL_CounterPeriod, &timer_period);
+
         /* Check initial time */
         osword_read_realtime(&t1);
 
         /* Read the Timer 0 value - it counts down from 19999 to 0,
          * the clock tick occurring as it changes from 0 to 19999.
          */
-        timer_count = get_t0_count();
+        if (iomd_check == 1)
+            timer_count = get_t0_count();
+        else
+            _swix(OS_Hardware, _INR(8,9)|_OUT(0), 0, EntryNo_HAL_CounterRead, &timer_count);
     }
 
     /* Check new time */
@@ -846,10 +868,10 @@ void microtime(struct timeval *tv)
     tv->tv_sec = machinetime_to_realtime(&t2, &tv->tv_usec);
     tv->tv_usec *= 10000;
 
-    if (iomd_check == 1 && t1.l == t2.l)
+    if (iomd_check != 2 && t1.l == t2.l)
     {
         /* Clock didn't tick - add in timer count */
-        tv->tv_usec += (19999 - timer_count) / 2;
+        tv->tv_usec += (timer_period - timer_count) / timer_divider;
     }
     else
     {