[sw] Manually test PULP Cluster offload

sw/tests/testClusterOffload.c

@@ -2,7 +2,8 @@
 // Licensed under the Apache License, Version 2.0, see LICENSE for details.
 // SPDX-License-Identifier: Apache-2.0
 //
-// Moritz Scherer <[email protected]>
+// Arpan Prasad <[email protected]>
+// Sergio Mazzola <[email protected]>
 
 // Simple offload test. Set the trap handler first, offload a function, retrieve
 // return value from cluster. Does not currently take care of stack
@@ -14,6 +15,7 @@
 #include <stdint.h>
 
 #define TESTVAL 0x050CCE55
+#define TESTVAL_CLUSTER 0xdeadbeef
 
 // static uint32_t *clintPointer = (uint32_t *)CLINT_CTRL_BASE;
 
@@ -27,9 +29,25 @@
 // }
 
 int32_t testReturn() {
-    return TESTVAL;
-}
+    int32_t result;
+
+    int32_t hartId;
+    asm("csrr %0, mhartid" : "=r"(hartId)::);
+
+
+    asm volatile (
+        "li t0, 0xdeadbeef\n"   // Load immediate value into t0 (x5)
+        "mv a0, t0\n"           // Move t0 into a0 (x10)
+        "mv %0, a0\n"           // Move a0 into the output variable (C)
+        : "=r"(result)          // Output operand
+        :                       // No input operands
+        : "t0", "a0"            // Clobbered registers
+    );
 
+    result = result + hartId;
+
+    return result;
+}
 int main() {
     // setupInterruptHandler(clusterTrapHandler);
     // offloadToCluster(testReturn, 0);
@@ -61,4 +79,4 @@ int main() {
     }
     return (count + TESTVAL+result);
     // }
-}
+}