diff --git a/sw/lib/handler.c b/sw/lib/handler.c
index cefe4e5..20d0ba7 100644
--- a/sw/lib/handler.c
+++ b/sw/lib/handler.c
@@ -2,7 +2,10 @@
 // Licensed under the Apache License, Version 2.0, see LICENSE for details.
 // SPDX-License-Identifier: Apache-2.0
 
+#include "handler.h"
+
 #include "common.h"
+#include "uart.h"
 
 /**
  * Default exception handler. Can be overidden.
@@ -24,23 +27,135 @@
  */
 void handler_irq_external(void) __attribute__((aligned(4), interrupt, weak));
 
+/**
+ * Instruction access fault. Can be overriden.
+ */
+void handler_instr_acc_fault(void) __attribute__((aligned(4), interrupt, weak));
+
+/**
+ * Illegal Instruction fault. Can be overriden.
+ */
+void handler_instr_ill_fault(void) __attribute__((aligned(4), interrupt, weak));
+;
+
+/**
+ * Breakpoint handler. Can be overriden.
+ */
+void handler_bkpt(void) __attribute__((aligned(4), interrupt, weak));
+
+/**
+ * Load store unit fault. Can be overriden.
+ */
+void handler_lsu_fault(void) __attribute__((aligned(4), interrupt, weak));
+
+/**
+ * Exception call handler. Can be overriden.
+ */
+void handler_ecall(void) __attribute__((aligned(4), interrupt, weak));
+
+/**
+ * Return value of mtval
+ */
+static uint32_t get_mtval(void) {
+  uint32_t mtval;
+  asm volatile("csrr %0, mtval" : "=r"(mtval) : :);
+  return mtval;
+}
+
+/**
+ * Default Error Handling
+ * @param error message supplied by caller
+ * TODO - this will be soon by a real print formatting
+ */
+static void print_exc_msg(const char *msg) {
+  const uint32_t mtval = get_mtval();
+  uart_send_str((char *)msg);
+  uart_send_str("MTVAL value is ");
+  uart_send_uint(mtval, 32);
+  uart_send_str("\n");
+  while (1) {
+  };
+}
+
 // Below functions are default weak exception handlers meant to be overriden
 void handler_exception(void) {
-  while (1) {
+  uint32_t mcause;
+  exc_id_t exc_cause;
+
+  asm volatile("csrr %0 , mcause" : "=r"(mcause) : :);
+  exc_cause = (exc_id_t)(mcause & kIdMax);
+
+  switch (exc_cause) {
+    case kInstMisa:
+      handler_instr_acc_fault();
+      break;
+    case kInstAccFault:
+      handler_instr_acc_fault();
+      break;
+    case kInstIllegalFault:
+      handler_instr_ill_fault();
+      break;
+    case kBkpt:
+      handler_bkpt();
+      break;
+    case kLoadAccFault:
+      handler_lsu_fault();
+      break;
+    case kStrAccFault:
+      handler_lsu_fault();
+      break;
+    case kECall:
+      handler_ecall();
+      break;
+    default:
+      while (1) {
+      };
   }
 }
 
 void handler_irq_software(void) {
+  uart_send_str("Software IRQ triggered!\n");
   while (1) {
   }
 }
 
 void handler_irq_timer(void) {
+  uart_send_str("Timer IRQ triggered!\n");
   while (1) {
   }
 }
 
 void handler_irq_external(void) {
+  uart_send_str("External IRQ triggered!\n");
+  while (1) {
+  }
+}
+
+void handler_instr_acc_fault(void) {
+  const char fault_msg[] =
+      "Instruction access fault, mtval shows fault address\n";
+  print_exc_msg(fault_msg);
+}
+
+void handler_instr_ill_fault(void) {
+  const char fault_msg[] =
+      "Illegal Instruction fault, mtval shows instruction content\n";
+  print_exc_msg(fault_msg);
+}
+
+void handler_bkpt(void) {
+  const char exc_msg[] =
+      "Breakpoint triggerd, mtval shows the breakpoint address\n";
+  print_exc_msg(exc_msg);
+}
+
+void handler_lsu_fault(void) {
+  const char exc_msg[] = "Load/Store fault, mtval shows the fault address\n";
+  print_exc_msg(exc_msg);
+}
+
+void handler_ecall(void) {
+  uart_send_str("Environment call encountered\n");
   while (1) {
   }
 }