sw: test divergence of all cpus

sw/sf2-test/crt0.S

@@ -17,15 +17,3 @@ _start:
 
         mv      a0, zero
         call    main
-
-        .global clear_bss
-clear_bss:
-        # clear the bss segment
-	la	t0, _fbss
-	la	t1, _end
-1:
-	sw	zero,0(t0)
-	addi	t0, t0, 4
-	bltu	t0, t1, 1b
-
-        ret

sw/sf2-test/main.c

@@ -19,9 +19,12 @@ extern void clear_bss(void);
 static enum t_test
   {
    TEST_WD,
-   TEST_CPU0_RECOVER,
-   TEST_CPU0_FATAL,
-   TEST_RAM
+   TEST_CPU1_RECOVER,
+   TEST_CPU2_RECOVER,
+   TEST_CPU3_RECOVER,
+   TEST_CPU1_FATAL,
+   TEST_RAM,
+   TEST_DONE
 } next_test;
 
 static void
@@ -112,14 +115,15 @@ ram_test(void)
   return 0;
 }
 
+/* ID must be 0-2 */
 static void
-force_divergence_1 (void)
+force_divergence (unsigned id)
 {
   unsigned v;
 
   /* Force divergence by executing different code.  */
   v = SUPERVISOR->force_divergence;
-  if (v != 1)
+  if (v != (1 << id))
     uart_putc('D');
 
   /* Must be in lock-step.  */
@@ -147,22 +151,21 @@ main (void)
   uart_put_hex_digit (next_test);
   uart_putc('\n');
 
-  if (v == 0)
-    clear_bss ();
-
   switch (next_test) {
   case TEST_WD:
-    next_test = TEST_CPU0_RECOVER;
+    /* Test watchdog - infinite loop */
+    next_test = TEST_CPU1_RECOVER;
     while (1)
       v = pad[0];
-    unreachable();
     break;
 
-  case TEST_CPU0_RECOVER:
+  case TEST_CPU1_RECOVER:
+  case TEST_CPU2_RECOVER:
+  case TEST_CPU3_RECOVER:
     SUPERVISOR->wd_key = WD_KEY;
-    force_divergence_1();
+    force_divergence(next_test - TEST_CPU1_RECOVER);
 
-    next_test = TEST_CPU0_FATAL;
+    next_test++;
 
     /* Generate reset for recovery */
     SUPERVISOR->cpu = HYDRA_SUPERVISOR_REGS_CPU_RECOVERY;
@@ -170,12 +173,12 @@ main (void)
     unreachable();
     break;
 
-  case TEST_CPU0_FATAL:
+  case TEST_CPU1_FATAL:
     SUPERVISOR->wd_key = WD_KEY;
     /* Clear recovery */
     SUPERVISOR->cpu = 0;
 
-    force_divergence_1();
+    force_divergence(0);
 
     next_test = TEST_RAM;
 
@@ -195,10 +198,15 @@ main (void)
       uart_put_hex_digit(v & 0x0f);
       unreachable();
     }
-  }
 
-  while (1) {
+    next_test = TEST_DONE;
+    /* Fallthrough */
+
+  case TEST_DONE:
     SUPERVISOR->wd_key = WD_KEY;
+    SUPERVISOR->wd_period = 100000000;
     uart_puts ("Hello diot.\n");
+    while (1)
+      ;
   }
 }