diff --git a/soc/runtime/comm.h b/soc/runtime/comm.h
index f30431448..bf4d9f91e 100644
--- a/soc/runtime/comm.h
+++ b/soc/runtime/comm.h
@@ -15,7 +15,7 @@ typedef int (*object_loader)(void *, int);
 typedef int (*kernel_runner)(const char *, int *, long long int *);
 
 void comm_serve(object_loader load_object, kernel_runner run_kernel);
-int comm_rpc_va(int rpc_num, va_list args);
+void comm_rpc_va(int rpc_num, va_list args, int *eid, int *retval);
 int comm_rpc(int rpc_num, ...);
 void comm_log_va(const char *fmt, va_list args);
 void comm_log(const char *fmt, ...);
diff --git a/soc/runtime/comm_serial.c b/soc/runtime/comm_serial.c
index 546010e44..77bbcce95 100644
--- a/soc/runtime/comm_serial.c
+++ b/soc/runtime/comm_serial.c
@@ -4,7 +4,11 @@
 #include <generated/csr.h>
 
 #include "comm.h"
+
+#ifndef ARTIQ_AMP
 #include "exceptions.h"
+#endif
+
 
 /* host to device */
 enum {
@@ -242,11 +246,9 @@ static int send_value(int type_tag, void *value)
     return 0;
 }
 
-int comm_rpc_va(int rpc_num, va_list args)
+void comm_rpc_va(int rpc_num, va_list args, int *eid, int *retval)
 {
     int type_tag;
-    int eid;
-    int retval;
 
     send_char(MSGTYPE_RPC_REQUEST);
     send_sint(rpc_num);
@@ -255,29 +257,25 @@ int comm_rpc_va(int rpc_num, va_list args)
         send_value(type_tag, type_tag == 'n' ? NULL : va_arg(args, void *));
     send_char(0);
 
-    eid = receive_int();
-    retval = receive_int();
-
-#ifdef ARTIQ_AMP
-#warning TODO
-#else
-    if(eid != EID_NONE)
-        exception_raise(eid);
-#endif
-
-    return retval;
+    *eid = receive_int();
+    *retval = receive_int();
 }
 
+#ifndef ARTIQ_AMP
 int comm_rpc(int rpc_num, ...)
 {
     va_list args;
-    int r;
+    int eid, retval;
 
     va_start(args, rpc_num);
-    r = comm_rpc_va(rpc_num, args);
+    comm_rpc_va(rpc_num, args, &eid, &retval);
     va_end(args);
-    return r;
+
+    if(eid != EID_NONE)
+        exception_raise(eid);
+    return retval;
 }
+#endif
 
 void comm_log_va(const char *fmt, va_list args)
 {
diff --git a/soc/runtime/ksupport.c b/soc/runtime/ksupport.c
index a9828592c..935d742f2 100644
--- a/soc/runtime/ksupport.c
+++ b/soc/runtime/ksupport.c
@@ -59,7 +59,7 @@ int comm_rpc(int rpc_num, ...)
 {
     struct msg_rpc_request request;
     struct msg_rpc_reply *reply;
-    int r;
+    int eid, retval;
 
     request.type = MESSAGE_TYPE_RPC_REQUEST;
     request.rpc_num = rpc_num;
@@ -70,9 +70,13 @@ int comm_rpc(int rpc_num, ...)
     reply = mailbox_wait_and_receive();
     if(reply->type != MESSAGE_TYPE_RPC_REPLY)
         exception_raise(EID_INTERNAL_ERROR);
-    r = reply->ret_val;
+    eid = reply->eid;
+    retval = reply->retval;
     mailbox_acknowledge();
-    return r;
+
+    if(eid != EID_NONE)
+        exception_raise(eid);
+    return retval;
 }
 
 void comm_log(const char *fmt, ...)
diff --git a/soc/runtime/main.c b/soc/runtime/main.c
index 36291c55b..4167037fe 100644
--- a/soc/runtime/main.c
+++ b/soc/runtime/main.c
@@ -90,7 +90,7 @@ static int process_msg(struct msg_unknown *umsg, int *eid, long long int *eparam
             struct msg_rpc_reply reply;
 
             reply.type = MESSAGE_TYPE_RPC_REPLY;
-            reply.ret_val = comm_rpc_va(msg->rpc_num, msg->args);
+            comm_rpc_va(msg->rpc_num, msg->args, &reply.eid, &reply.retval);
             mailbox_send_and_wait(&reply);
             return KERNEL_RUN_INVALID_STATUS;
         }
diff --git a/soc/runtime/messages.h b/soc/runtime/messages.h
index d79d8e354..274d40cf1 100644
--- a/soc/runtime/messages.h
+++ b/soc/runtime/messages.h
@@ -33,7 +33,8 @@ struct msg_rpc_request {
 
 struct msg_rpc_reply {
     int type;
-    int ret_val;
+    int eid;
+    int retval;
 };
 
 struct msg_log {