diff --git a/.gitignore b/.gitignore
index cc65b37..be682f9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
+build/
 *.~lock*
\ No newline at end of file
diff --git a/testbench/basic_test/Makefile b/testbench/basic_test/Makefile
index b9ea799..84ceb8b 100644
--- a/testbench/basic_test/Makefile
+++ b/testbench/basic_test/Makefile
@@ -12,8 +12,8 @@ OBJ = $(notdir $(SOURCE_AS:.S=.o))
 OBJ += $(notdir $(SOURCE_C:.c=.o))
 
 CC = riscv64-linux-gnu-gcc-8
-# CFLAGS = -march=rv32i -mabi=ilp32
-CFLAGS = -march=rv64i -mabi=lp64
+CFLAGS = -march=rv32i -mabi=ilp32
+# CFLAGS = -march=rv64i -mabi=lp64
 
 CPPFLAGS =
 
@@ -21,7 +21,7 @@ AS = riscv64-linux-gnu-as
 ASFLAGS = $(CFLAGS)
 
 LD = riscv64-linux-gnu-ld
-LDFLAGS = -T
+LDFLAGS = -melf32lriscv_ilp32
 
 
 # $(info $$TESTBENCH_V is [${TESTBENCH_V}])
@@ -39,7 +39,7 @@ LDFLAGS = -T
 	$(CC) $(CPPFLAGS) $(CFLAGS) $^ -o $@
 
 %.elf: %.ld $(OBJ)
-	$(LD) $(LDFLAGS) $^ -o $@
+	$(LD) $(LDFLAGS) -T $^ -o $@
 
 %.hex: %.elf
 	riscv64-linux-gnu-objcopy --target=verilog $< $@
diff --git a/testbench/basic_test/test.S b/testbench/basic_test/test.S
index 130a4b3..3b99f1b 100644
--- a/testbench/basic_test/test.S
+++ b/testbench/basic_test/test.S
@@ -50,19 +50,16 @@ _start:
     # slli
     slli    x24, x23, 4         # x24 = 0x00007880
     slli    x25, x2, 1          # x25 = 0xfffffffe
-    slli    x26, x2, 63         # x26 = 0x80000000  # NOTE: gcc should not allow this since shamt is only 5 bits. discarding high bit so 63 = 31
     slli    x27, x2, 31         # x27 = 0x80000000
 
     # srli
     srli    x28, x23, 4         # x28 = 0x00000078
     srli    x29, x2, 1          # x29 = 0x7fffffff
-    srli    x30, x2, 63         # x30 = 0x00000001  # NOTE: gcc should not allow this since shamt is only 5 bits. discarding high bit so 63 = 31
     srli    x3, x2, 31          # x3  = 0x00000001
 
     # srai
     srai    x4, x23, 4          # x4  = 0x00000078
     srai    x5, x2, 1           # x5  = 0xffffffff
-    srai    x6, x2, 63          # x6  = 0xffffffff  # NOTE: gcc should not allow this since shamt is only 5 bits. discarding high bit so 63 = 31
     srai    x7, x2, 31          # x7  = 0xffffffff
 
     # sll