equi

commit 7e7544a15a930fcf8b1b55a1636b591702178573
parent 93f19d3a17cd100e1f391b6f68aed8518213712f
Author: Luxferre <lux@ferre>
Date:   Sun, 14 Aug 2022 16:15:44 +0300

Implemented some task control portio

Diffstat:
M
equi.c
 | 
28
++++++++++++++++++++++++++++

1 file changed, 28 insertions(+), 0 deletions(-)
diff --git a/equi.c b/equi.c
@@ -388,17 +388,45 @@ ushort persistOp(FILE *pfd, ushort maddr, ushort dataLen, ushort blk, uchar isWr
 void portIO(ushort port, ushort p2, ushort p1) {
   ushort r1 = 0, r2 = 0, status = 0;
   switch(port) {
+    /* Echo port (for testing): r1 = p1, r2 = p2 */
     case PORT_ECHO:
       r1 = p1;
       r2 = p2;
       break;
+    /* Random number generator port: p1 = from, p2 = to, r1 and r2 = rand(from, to) */
     case PORT_RANDOM:
       r1 = (ushort) (p1 + (rand()%p2));
       r2 = (ushort) (p1 + (rand()%p2));
       break;
+    /* Checksum port: p1 = address, p2 = length, r1 = CRC-16-CCITT value */
     case PORT_CHECKSUM:
       r1 = crc16(&flatram[p1], p2);
       break;
+    /* Task control port: p1 = task ID, p2 = operation code */
+    /* Operations: 0 - get status, 1 - set active status, 2 - unset active status, 3 - get privilege status */ 
+    /* Only privileged tasks can change status of other tasks, otherwise fail silently */
+    case PORT_TASKCTL:
+      if(p1 >= EQUI_TASKS_MAX) {
+        trapout(OUT_OF_BOUNDS_JUMP);
+        return;
+      }
+      switch(p2) {
+        case 0:
+          r1 = ram.tasks[p1].active;
+          break;
+        case 1:
+          if(curtask->privileged)
+            ram.tasks[p1].active = 1;
+          break;
+        case 2:
+          if(curtask->privileged)
+            ram.tasks[p1].active = 0;
+          break;
+        case 3:
+           r1 = ram.tasks[p1].privileged; 
+           break;
+      }
+      break;
     default:
       fprintf(stderr, "[PORTIO] Unimplemented call to port 0x%X with P1=%X and P2=%X\n", port, p1, p2);
   }