Changeset 95 for trunk/hal/tsar_mips32/core/hal_special.c

Timestamp:

Jun 29, 2017, 1:40:15 PM (7 years ago)

Author:

alain

Message:

hal_special: replace hal_time_stamp() by hal_get_cycles()
hal_remote : remove hal_remove_unc()

File:

• trunk/hal/tsar_mips32/core/hal_special.c (modified) (1 diff)

trunk/hal/tsar_mips32/core/hal_special.c

@@ -42 +42 @@
 
 /////////////////////////
-uint32_t hal_time_stamp()
-{
-        uint32_t cycles;
-  
-        asm volatile ("mfc0   %0,  $9  " : "=&r" (cycles));
-  
+uint64_t hal_get_cycles()
+{
+        uint64_t cycles;                // absolute time to be returned
+    uint32_t last_count;            // last registered cycles count
+    uint32_t current_count;         // current cycles count
+        uint32_t elapsed;
+
+    core_t * core = CURRENT_THREAD->core;
+
+    // get last registered time stamp
+        last_count = core->time_stamp;
+
+    // get current time stamp from hardware register
+        asm volatile ("mfc0   %0,  $9  " : "=&r" (current_count));
+
+        // compute number of elapsed cycles, taking into account 32 bits register wrap
+        if(current_count < last_count) elapsed = (0xFFFFFFFF - last_count) + current_count;
+        else                           elapsed = current_count - last_count;
+
+    // compute absolute time
+        cycles = core->cycles + elapsed;
+
+        // update core time
+        core->time_stamp = current_count;
+        core->cycles     = cycles;
+
+        hal_wbflush();
+
         return cycles;
 }