diff --git a/tests/C/trace/Makefile b/tests/C/trace/Makefile
index 7026d26..c0aa67c 100644
--- a/tests/C/trace/Makefile
+++ b/tests/C/trace/Makefile
@@ -2,14 +2,14 @@ TARGET   = trace
 
 TARGET_ARCH=riscv32
 
-CC       = riscv32-unknown-linux-gnu-gcc
+CC       = riscv32-unknown-elf-gcc
 # compiling flags here
 #CFLAGS   = -Wall -I. -O0 -nostartfiles  -march=rv32i -mabi=ilp32
 CFLAGS = -Wall -I. -O0 -nostdlib -march=rv32i -mabi=ilp32 --entry main
 #CFLAGS = -Wall -I. -O0 -nodefaultlibs -march=rv32i -mabi=ilp32
 
 
-LINKER   = riscv32-unknown-linux-gnu-gcc
+LINKER   = riscv32-unknown-elf-gcc
 # linking flags here
 LFLAGS   = -I. --entry main
 LIBS   = $(EXTRA_LIBS)
diff --git a/tests/C/trace/trace.c b/tests/C/trace/trace.c
index c1727c0..7bfc59c 100644
--- a/tests/C/trace/trace.c
+++ b/tests/C/trace/trace.c
@@ -1,7 +1,7 @@
 
 #define TRACE (*(unsigned char *)0x40000000)
 
-void main(void) {
+int main(void) {
   TRACE = 'H';
   TRACE = 'e';
 
diff --git a/tests/C/trace2/Makefile b/tests/C/trace2/Makefile
index 9b2501f..a6b7721 100644
--- a/tests/C/trace2/Makefile
+++ b/tests/C/trace2/Makefile
@@ -2,14 +2,14 @@ TARGET   = trace2
 
 TARGET_ARCH=riscv32
 
-CC       = riscv32-unknown-linux-gnu-gcc
+CC       = riscv32-unknown-elf-gcc
 # compiling flags here
 #CFLAGS   = -Wall -I. -O0 -nostartfiles  -march=rv32i -mabi=ilp32
 CFLAGS = -Wall -I. -O0 -nostdlib -march=rv32i -mabi=ilp32 --entry main
 #CFLAGS = -Wall -I. -O0 -nodefaultlibs -march=rv32i -mabi=ilp32
 
 
-LINKER   = riscv32-unknown-linux-gnu-gcc
+LINKER   = riscv32-unknown-elf-gcc
 # linking flags here
 LFLAGS   = -I. --entry main
 LIBS   = $(EXTRA_LIBS)
diff --git a/tests/C/trace2/trace2.c b/tests/C/trace2/trace2.c
index 1e537f9..911a717 100644
--- a/tests/C/trace2/trace2.c
+++ b/tests/C/trace2/trace2.c
@@ -1,7 +1,7 @@
 
 #define TRACE (*(unsigned char *)0x40000000)
 
-void main(void) {
+int main(void) {
   int i;
   for(i=0;i<10;i++) {
     TRACE = 'a' + i;
diff --git a/tests/C/trace3/Makefile b/tests/C/trace3/Makefile
index 554024f..fa92738 100644
--- a/tests/C/trace3/Makefile
+++ b/tests/C/trace3/Makefile
@@ -2,14 +2,14 @@ TARGET   = trace3
 
 TARGET_ARCH=riscv32
 
-CC       = riscv32-unknown-linux-gnu-gcc
+CC       = riscv32-unknown-elf-gcc
 # compiling flags here
 #CFLAGS   = -Wall -I. -O0 -nostartfiles  -march=rv32i -mabi=ilp32
 CFLAGS = -Wall -I. -O0 -nostdlib -march=rv32i -mabi=ilp32 --entry main
 #CFLAGS = -Wall -I. -O0 -nodefaultlibs -march=rv32i -mabi=ilp32
 
 
-LINKER   = riscv32-unknown-linux-gnu-gcc
+LINKER   = riscv32-unknown-elf-gcc
 # linking flags here
 LFLAGS   = -I. --entry main
 LIBS   = $(EXTRA_LIBS)
diff --git a/tests/C/trace3/trace3.c b/tests/C/trace3/trace3.c
index c93921b..3a9eb52 100644
--- a/tests/C/trace3/trace3.c
+++ b/tests/C/trace3/trace3.c
@@ -1,12 +1,13 @@
 #define TRACE (*(unsigned char *)0x40000000)
 
-void main(void) {
+int main(void) {
   char msg[] = "abcdefg\n";
   int i;
 
   for (i=0; i<5; i++) {
     TRACE = msg[i];
   }
-
+  asm volatile ("rdcycle t0");
+  asm volatile ("rdtime t4");
   asm volatile ("ecall");
 }