diff --git a/examples/fibonacci.s b/examples/fibonacci.s
index 20dab08f..192122f8 100644
--- a/examples/fibonacci.s
+++ b/examples/fibonacci.s
@@ -15,24 +15,24 @@ __start:
   li t0, 0
   li t1, 1
   # prints msg1
-  li a0, 4
-  la a1, msg1
+  li a7, 4
+  la a0, msg1
   ecall
   # reads an int and moves it to register t3
-  li a0, 5
+  li a7, 5
   ecall
   mv t3, a0
   # prints a newline
-  li a0, 11
-  li a1, '\n'
+  li a7, 11
+  li a0, '\n'
   ecall
   # prints msg2
-  li a0, 4
-  la a1, msg2
+  li a7, 4
+  la a0, msg2
   ecall
   # prints the int value in t3
-  li a0, 1
-  mv a1, t3
+  li a7, 1
+  mv a0, t3
   ecall
   # fibonnaci program
 fib:
@@ -44,13 +44,13 @@ fib:
   j fib
 finish:
   # prints msg3
-  li a0, 4
-  la a1, msg3
+  li a7, 4
+  la a0, msg3
   ecall
   # prints the result in t0
-  li a0, 1
-  mv a1, t0
+  li a7, 1
+  mv a0, t0
   ecall
   # ends the program with status code 0
-  li a0, 10
+  li a7, 10
   ecall
diff --git a/src/main/java/jupiter/riscv/Syscall.java b/src/main/java/jupiter/riscv/Syscall.java
index 8f3c3583..1e10eb83 100644
--- a/src/main/java/jupiter/riscv/Syscall.java
+++ b/src/main/java/jupiter/riscv/Syscall.java
@@ -93,7 +93,7 @@ public final class Syscall {
    */
   public static void handler(State state) throws SimulationException {
     // match ecall code
-    switch (state.xregfile().getRegister("a0")) {
+    switch (state.xregfile().getRegister("a7")) {
       case PRINT_INT:
         printInt(state);
         break;
@@ -173,7 +173,7 @@ public static void handler(State state) throws SimulationException {
         randFloat(state);
         break;
       default:
-        throw new SimulationException("invalid ecall code: " + state.xregfile().getRegister("a0"));
+        throw new SimulationException("invalid ecall code: " + state.xregfile().getRegister("a7"));
     }
   }
 
@@ -184,7 +184,7 @@ public static void handler(State state) throws SimulationException {
    */
   private static void printInt(State state) {
     Globals.PRINT = true;
-    int num = state.xregfile().getRegister("a1");
+    int num = state.xregfile().getRegister("a0");
     IO.stdout().print(Integer.toString(num));
   }
 
@@ -206,7 +206,7 @@ private static void printFloat(State state) {
    */
   private static void printString(State state) throws SimulationException {
     Globals.PRINT = true;
-    int buffer = state.xregfile().getRegister("a1");
+    int buffer = state.xregfile().getRegister("a0");
     // 65684
     StringBuilder s = new StringBuilder(0);
     char c;
@@ -249,8 +249,8 @@ private static void readFloat(State state) throws SimulationException {
    * @param state program state
    */
   private static void readString(State state) throws SimulationException {
-    int buffer = state.xregfile().getRegister("a1");
-    int length = Math.max(state.xregfile().getRegister("a2") - 1, 0);
+    int buffer = state.xregfile().getRegister("a0");
+    int length = Math.max(state.xregfile().getRegister("a1") - 1, 0);
     String s = IO.readString(length);
     int minLength = Math.min(length, s.length());
     for (int i = 0; i < minLength; i++) {
@@ -266,7 +266,7 @@ private static void readString(State state) throws SimulationException {
    * @param state program state
    */
   private static void sbrk(State state) throws SimulationException {
-    int numBytes = state.xregfile().getRegister("a1");
+    int numBytes = state.xregfile().getRegister("a0");
     if (numBytes >= 0) {
       int address = state.memory().allocateBytesFromHeap(numBytes);
       state.xregfile().setRegister("a0", address);
@@ -287,7 +287,7 @@ private static void exit() throws SimulationException {
    */
   private static void printChar(State state) {
     Globals.PRINT = true;
-    IO.stdout().print((char) state.xregfile().getRegister("a1") + "");
+    IO.stdout().print((char) state.xregfile().getRegister("a0") + "");
   }
 
   /**
@@ -305,8 +305,8 @@ private static void readChar(State state) {
    * @param state program state
    */
   private static void open(State state) throws SimulationException{
-    int buffer = state.xregfile().getRegister("a1");
-    int oflags = state.xregfile().getRegister("a2");
+    int buffer = state.xregfile().getRegister("a0");
+    int oflags = state.xregfile().getRegister("a1");
     state.xregfile().setRegister("a0", VirtualFS.open(buffer, oflags, state));
   }
 
@@ -316,9 +316,9 @@ private static void open(State state) throws SimulationException{
    * @param state program state
    */
   private static void read(State state) throws SimulationException {
-    int fd = state.xregfile().getRegister("a1");
-    int buffer = state.xregfile().getRegister("a2");
-    int nbytes = state.xregfile().getRegister("a3");
+    int fd = state.xregfile().getRegister("a0");
+    int buffer = state.xregfile().getRegister("a1");
+    int nbytes = state.xregfile().getRegister("a2");
     if (nbytes > 0) {
       state.xregfile().setRegister("a0", VirtualFS.read(fd, buffer, nbytes, state));
     } else {
@@ -332,9 +332,9 @@ private static void read(State state) throws SimulationException {
    * @param state program state
    */
   private static void write(State state) throws SimulationException {
-    int fd = state.xregfile().getRegister("a1");
-    int buffer = state.xregfile().getRegister("a2");
-    int nbytes = state.xregfile().getRegister("a3");
+    int fd = state.xregfile().getRegister("a0");
+    int buffer = state.xregfile().getRegister("a1");
+    int nbytes = state.xregfile().getRegister("a2");
     if (nbytes > 0) {
       state.xregfile().setRegister("a0", VirtualFS.write(fd, buffer, nbytes, state));
     } else {
@@ -348,9 +348,9 @@ private static void write(State state) throws SimulationException {
    * @param state program state
    */
   private static void lseek(State state) throws SimulationException {
-    int fd = state.xregfile().getRegister("a1");
-    int offset = state.xregfile().getRegister("a2");
-    int whence = state.xregfile().getRegister("a3");
+    int fd = state.xregfile().getRegister("a0");
+    int offset = state.xregfile().getRegister("a1");
+    int whence = state.xregfile().getRegister("a2");
     state.xregfile().setRegister("a0", VirtualFS.lseek(fd, offset, whence));
   }
 
@@ -360,7 +360,7 @@ private static void lseek(State state) throws SimulationException {
    * @param state program state
    */
   private static void close(State state) {
-    state.xregfile().setRegister("a0", VirtualFS.close(state.xregfile().getRegister("a1")));
+    state.xregfile().setRegister("a0", VirtualFS.close(state.xregfile().getRegister("a0")));
   }
 
   /**
@@ -369,7 +369,7 @@ private static void close(State state) {
    * @param state program state
    */
   private static void exit2(State state) throws SimulationException {
-    throw new HaltException(state.xregfile().getRegister("a1"));
+    throw new HaltException(state.xregfile().getRegister("a0"));
   }
 
   /**
@@ -378,7 +378,7 @@ private static void exit2(State state) throws SimulationException {
    * @param state program state
    */
   private static void sleep(State state) throws SimulationException {
-    int millis = state.xregfile().getRegister("a1");
+    int millis = state.xregfile().getRegister("a0");
     if (millis >= 0) {
       try {
         Thread.sleep(millis);
@@ -395,7 +395,7 @@ private static void sleep(State state) throws SimulationException {
    */
   private static void cwd(State state) throws SimulationException {
     String path = System.getProperty("user.dir");
-    int buffer = state.xregfile().getRegister("a1");
+    int buffer = state.xregfile().getRegister("a0");
     for (int i = 0; i < path.length(); i++) {
       state.memory().storeByte(buffer++, (int) path.charAt(i));
     }
@@ -420,7 +420,7 @@ private static void time(State state) {
    */
   private static void printHex(State state) {
     Globals.PRINT = true;
-    IO.stdout().print(String.format("0x%08x", state.xregfile().getRegister("a1")));
+    IO.stdout().print(String.format("0x%08x", state.xregfile().getRegister("a0")));
   }
 
   /**
@@ -430,7 +430,7 @@ private static void printHex(State state) {
    */
   private static void printBin(State state) {
     Globals.PRINT = true;
-    IO.stdout().print(String.format("0b%32s", Integer.toBinaryString(state.xregfile().getRegister("a1"))).replace(' ', '0'));
+    IO.stdout().print(String.format("0b%32s", Integer.toBinaryString(state.xregfile().getRegister("a0"))).replace(' ', '0'));
   }
 
   /**
@@ -440,7 +440,7 @@ private static void printBin(State state) {
    */
   private static void printUsgn(State state) {
     Globals.PRINT = true;
-    IO.stdout().print(Long.toString(Integer.toUnsignedLong(state.xregfile().getRegister("a1"))));
+    IO.stdout().print(Long.toString(Integer.toUnsignedLong(state.xregfile().getRegister("a0"))));
   }
 
   /**
@@ -449,7 +449,7 @@ private static void printUsgn(State state) {
    * @param state program state
    */
   private static void setSeed(State state) {
-    RNG.setSeed(state.xregfile().getRegister("a1"));
+    RNG.setSeed(state.xregfile().getRegister("a0"));
   }
 
   /**
@@ -467,8 +467,8 @@ private static void randInt(State state) {
    * @param state program state
    */
   private static void randIntRng(State state) {
-    int min = state.xregfile().getRegister("a1");
-    int max = state.xregfile().getRegister("a2");
+    int min = state.xregfile().getRegister("a0");
+    int max = state.xregfile().getRegister("a1");
     state.xregfile().setRegister("a0", RNG.nextInt((max - min) + 1) + min);
   }
 
diff --git a/src/test/others/print.s b/src/test/others/print.s
index 45340d6e..e298c1fb 100644
--- a/src/test/others/print.s
+++ b/src/test/others/print.s
@@ -1,7 +1,6 @@
 .globl print
 
 print:
-  mv a1, a0
-  li a0, 1
+  li a7, 1
   ecall
   ret
diff --git a/src/test/others/test.s b/src/test/others/test.s
index 6eedf340..f86a6d24 100644
--- a/src/test/others/test.s
+++ b/src/test/others/test.s
@@ -3,5 +3,5 @@
 __start:
   li a0, 0xbb
   call print
-  li a0, 10
+  li a7, 10
   ecall
diff --git a/src/test/riscv-tests/add.s b/src/test/riscv-tests/add.s
index 0d455767..8e9a6cf5 100644
--- a/src/test/riscv-tests/add.s
+++ b/src/test/riscv-tests/add.s
@@ -409,9 +409,9 @@ test37:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/addi.s b/src/test/riscv-tests/addi.s
index 04ce1951..a3f48577 100644
--- a/src/test/riscv-tests/addi.s
+++ b/src/test/riscv-tests/addi.s
@@ -215,9 +215,9 @@ test24:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/and.s b/src/test/riscv-tests/and.s
index 323c84f2..81424f37 100644
--- a/src/test/riscv-tests/and.s
+++ b/src/test/riscv-tests/and.s
@@ -321,9 +321,9 @@ test26:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/andi.s b/src/test/riscv-tests/andi.s
index f2a585f7..5e616357 100644
--- a/src/test/riscv-tests/andi.s
+++ b/src/test/riscv-tests/andi.s
@@ -138,9 +138,9 @@ test13:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/auipc.s b/src/test/riscv-tests/auipc.s
index ea430d82..d5edc7ae 100644
--- a/src/test/riscv-tests/auipc.s
+++ b/src/test/riscv-tests/auipc.s
@@ -31,9 +31,9 @@ label3_test01:
   ret
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/beq.s b/src/test/riscv-tests/beq.s
index 6312eca2..96a4afdf 100644
--- a/src/test/riscv-tests/beq.s
+++ b/src/test/riscv-tests/beq.s
@@ -244,9 +244,9 @@ label1_test19:
   bne x4, x5, label1_test19
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/bge.s b/src/test/riscv-tests/bge.s
index 949cb14a..e642be5d 100644
--- a/src/test/riscv-tests/bge.s
+++ b/src/test/riscv-tests/bge.s
@@ -283,9 +283,9 @@ label1_test22:
   bne x4, x5, label1_test22
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/bgeu.s b/src/test/riscv-tests/bgeu.s
index 697be973..87eb5de0 100644
--- a/src/test/riscv-tests/bgeu.s
+++ b/src/test/riscv-tests/bgeu.s
@@ -283,9 +283,9 @@ label1_test22:
   bne x4, x5, label1_test22
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/blt.s b/src/test/riscv-tests/blt.s
index 34f3b989..48c6782c 100644
--- a/src/test/riscv-tests/blt.s
+++ b/src/test/riscv-tests/blt.s
@@ -244,9 +244,9 @@ label1_test19:
   bne x4, x5, label1_test19
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/bltu.s b/src/test/riscv-tests/bltu.s
index 573b5126..84f6598a 100644
--- a/src/test/riscv-tests/bltu.s
+++ b/src/test/riscv-tests/bltu.s
@@ -244,9 +244,9 @@ label1_test19:
   bne x4, x5, label1_test19
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/bne.s b/src/test/riscv-tests/bne.s
index 16a0941c..8f581820 100644
--- a/src/test/riscv-tests/bne.s
+++ b/src/test/riscv-tests/bne.s
@@ -245,9 +245,9 @@ label1_test19:
   bne x4, x5, label1_test19
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/csr.s b/src/test/riscv-tests/csr.s
index e07fac94..aeb5de11 100644
--- a/src/test/riscv-tests/csr.s
+++ b/src/test/riscv-tests/csr.s
@@ -17,5 +17,5 @@ test:
   csrrci x1, 0, 0
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
diff --git a/src/test/riscv-tests/div.s b/src/test/riscv-tests/div.s
index 190f9b59..4105bc37 100644
--- a/src/test/riscv-tests/div.s
+++ b/src/test/riscv-tests/div.s
@@ -81,9 +81,9 @@ test09:
   bne x30, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/divu.s b/src/test/riscv-tests/divu.s
index 8f8f6618..2143faf8 100644
--- a/src/test/riscv-tests/divu.s
+++ b/src/test/riscv-tests/divu.s
@@ -81,9 +81,9 @@ test09:
   bne x30, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/ecall.s b/src/test/riscv-tests/ecall.s
index 24d1fa6b..0f7f05fa 100644
--- a/src/test/riscv-tests/ecall.s
+++ b/src/test/riscv-tests/ecall.s
@@ -9,10 +9,10 @@
 __start:
 
 test:
-  li a0, 1
-  li a2, 0xa
+  li a7, 1
+  li a0, 0xa
   ecall
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
diff --git a/src/test/riscv-tests/farith.s b/src/test/riscv-tests/farith.s
index 3a6956fd..3852fc2c 100644
--- a/src/test/riscv-tests/farith.s
+++ b/src/test/riscv-tests/farith.s
@@ -189,9 +189,9 @@ test10_data:
   .text
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/farith2.s b/src/test/riscv-tests/farith2.s
index 11778e06..503f255c 100644
--- a/src/test/riscv-tests/farith2.s
+++ b/src/test/riscv-tests/farith2.s
@@ -117,9 +117,9 @@ test07_data:
   .text
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/fclass.s b/src/test/riscv-tests/fclass.s
index 2ab9cf3a..faafa7f0 100644
--- a/src/test/riscv-tests/fclass.s
+++ b/src/test/riscv-tests/fclass.s
@@ -89,9 +89,9 @@ test10:
   bne a0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/fcmp.s b/src/test/riscv-tests/fcmp.s
index e6e74185..80724e36 100644
--- a/src/test/riscv-tests/fcmp.s
+++ b/src/test/riscv-tests/fcmp.s
@@ -264,9 +264,9 @@ test15_data:
   .text
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/fcvt.s b/src/test/riscv-tests/fcvt.s
index 1e29f2e3..6b9b54d1 100644
--- a/src/test/riscv-tests/fcvt.s
+++ b/src/test/riscv-tests/fcvt.s
@@ -144,9 +144,9 @@ test10_data:
   .text
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/fence.s b/src/test/riscv-tests/fence.s
index f2403a74..de9877bd 100644
--- a/src/test/riscv-tests/fence.s
+++ b/src/test/riscv-tests/fence.s
@@ -12,5 +12,5 @@ test:
   fence
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
diff --git a/src/test/riscv-tests/ffused.s b/src/test/riscv-tests/ffused.s
index f0041483..df7dcfd7 100644
--- a/src/test/riscv-tests/ffused.s
+++ b/src/test/riscv-tests/ffused.s
@@ -225,9 +225,9 @@ test12_data:
   .text
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/fls.s b/src/test/riscv-tests/fls.s
index c35f77c0..4e90f563 100644
--- a/src/test/riscv-tests/fls.s
+++ b/src/test/riscv-tests/fls.s
@@ -39,9 +39,9 @@ test02:
   bne a0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/fminmax.s b/src/test/riscv-tests/fminmax.s
index cdb04526..b6404524 100644
--- a/src/test/riscv-tests/fminmax.s
+++ b/src/test/riscv-tests/fminmax.s
@@ -333,9 +333,9 @@ test32_data:
   .text
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/fmove.s b/src/test/riscv-tests/fmove.s
index 7e08239f..a3c1ce4c 100644
--- a/src/test/riscv-tests/fmove.s
+++ b/src/test/riscv-tests/fmove.s
@@ -141,9 +141,9 @@ test32:
   bne a0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/frecoding.s b/src/test/riscv-tests/frecoding.s
index 218830ad..1c00db35 100644
--- a/src/test/riscv-tests/frecoding.s
+++ b/src/test/riscv-tests/frecoding.s
@@ -58,9 +58,9 @@ test06:
   bne a0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/jal.s b/src/test/riscv-tests/jal.s
index 7614767d..75deb731 100644
--- a/src/test/riscv-tests/jal.s
+++ b/src/test/riscv-tests/jal.s
@@ -21,9 +21,9 @@ target_2:
   bne x2, x4, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/jalr.s b/src/test/riscv-tests/jalr.s
index 2d6df60b..98b1a8da 100644
--- a/src/test/riscv-tests/jalr.s
+++ b/src/test/riscv-tests/jalr.s
@@ -59,9 +59,9 @@ label2_test04:
   bne x4, x5, label1_test04
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/lb.s b/src/test/riscv-tests/lb.s
index efb4bec2..e19b39a4 100644
--- a/src/test/riscv-tests/lb.s
+++ b/src/test/riscv-tests/lb.s
@@ -187,9 +187,9 @@ test18:
   bne x2, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/lbu.s b/src/test/riscv-tests/lbu.s
index 49414e88..a4c632ab 100644
--- a/src/test/riscv-tests/lbu.s
+++ b/src/test/riscv-tests/lbu.s
@@ -187,9 +187,9 @@ test18:
   bne x2, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/lh.s b/src/test/riscv-tests/lh.s
index a8ba2c98..cf1d851e 100644
--- a/src/test/riscv-tests/lh.s
+++ b/src/test/riscv-tests/lh.s
@@ -187,9 +187,9 @@ test18:
   bne x2, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/lhu.s b/src/test/riscv-tests/lhu.s
index 96a06e58..d70091bc 100644
--- a/src/test/riscv-tests/lhu.s
+++ b/src/test/riscv-tests/lhu.s
@@ -187,9 +187,9 @@ test18:
   bne x2, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/lui.s b/src/test/riscv-tests/lui.s
index 1940d591..6b5da857 100644
--- a/src/test/riscv-tests/lui.s
+++ b/src/test/riscv-tests/lui.s
@@ -42,9 +42,9 @@ test05:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/lw.s b/src/test/riscv-tests/lw.s
index 39bafa85..b7403636 100644
--- a/src/test/riscv-tests/lw.s
+++ b/src/test/riscv-tests/lw.s
@@ -187,9 +187,9 @@ test18:
   bne x2, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/mul.s b/src/test/riscv-tests/mul.s
index 96c41a5e..9d031230 100644
--- a/src/test/riscv-tests/mul.s
+++ b/src/test/riscv-tests/mul.s
@@ -401,9 +401,9 @@ test28:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/mulh.s b/src/test/riscv-tests/mulh.s
index 8ab57a27..d5fc93b7 100644
--- a/src/test/riscv-tests/mulh.s
+++ b/src/test/riscv-tests/mulh.s
@@ -385,9 +385,9 @@ test28:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/mulhsu.s b/src/test/riscv-tests/mulhsu.s
index 37964ab8..4490128c 100644
--- a/src/test/riscv-tests/mulhsu.s
+++ b/src/test/riscv-tests/mulhsu.s
@@ -385,9 +385,9 @@ test28:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/mulhu.s b/src/test/riscv-tests/mulhu.s
index fb299507..4e5beb45 100644
--- a/src/test/riscv-tests/mulhu.s
+++ b/src/test/riscv-tests/mulhu.s
@@ -385,9 +385,9 @@ test28:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/or.s b/src/test/riscv-tests/or.s
index 2de6a16a..07e2aadb 100644
--- a/src/test/riscv-tests/or.s
+++ b/src/test/riscv-tests/or.s
@@ -321,9 +321,9 @@ test26:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/ori.s b/src/test/riscv-tests/ori.s
index 9111f84d..8d45c029 100644
--- a/src/test/riscv-tests/ori.s
+++ b/src/test/riscv-tests/ori.s
@@ -138,9 +138,9 @@ test13:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/refs.s b/src/test/riscv-tests/refs.s
index 57369e8b..1f42ad9c 100644
--- a/src/test/riscv-tests/refs.s
+++ b/src/test/riscv-tests/refs.s
@@ -24,9 +24,9 @@ test01:
   bne x2, x4, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/relocations.s b/src/test/riscv-tests/relocations.s
index 6de9ee14..6109257a 100644
--- a/src/test/riscv-tests/relocations.s
+++ b/src/test/riscv-tests/relocations.s
@@ -19,9 +19,9 @@ test01:
   bne x1, x2, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/rem.s b/src/test/riscv-tests/rem.s
index 4afa2010..dc904da9 100644
--- a/src/test/riscv-tests/rem.s
+++ b/src/test/riscv-tests/rem.s
@@ -81,9 +81,9 @@ test09:
   bne x30, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/remu.s b/src/test/riscv-tests/remu.s
index 5094c686..25025e1b 100644
--- a/src/test/riscv-tests/remu.s
+++ b/src/test/riscv-tests/remu.s
@@ -81,9 +81,9 @@ test09:
   bne x30, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/sb.s b/src/test/riscv-tests/sb.s
index aed21f27..e03eecb6 100644
--- a/src/test/riscv-tests/sb.s
+++ b/src/test/riscv-tests/sb.s
@@ -300,9 +300,9 @@ label1_test22:
   bne x4, x5, label1_test22
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/sh.s b/src/test/riscv-tests/sh.s
index e7f23ebb..a206a597 100644
--- a/src/test/riscv-tests/sh.s
+++ b/src/test/riscv-tests/sh.s
@@ -300,9 +300,9 @@ label1_test22:
   bne x4, x5, label1_test22
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/sll.s b/src/test/riscv-tests/sll.s
index a82d4e85..5d7fc8a8 100644
--- a/src/test/riscv-tests/sll.s
+++ b/src/test/riscv-tests/sll.s
@@ -441,9 +441,9 @@ test42:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/slli.s b/src/test/riscv-tests/slli.s
index 23309f2f..ae425dc1 100644
--- a/src/test/riscv-tests/slli.s
+++ b/src/test/riscv-tests/slli.s
@@ -215,9 +215,9 @@ test24:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/slt.s b/src/test/riscv-tests/slt.s
index dbd2b85a..4e91d940 100644
--- a/src/test/riscv-tests/slt.s
+++ b/src/test/riscv-tests/slt.s
@@ -409,9 +409,9 @@ test37:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/slti.s b/src/test/riscv-tests/slti.s
index 4c3267a9..0ec1ae5c 100644
--- a/src/test/riscv-tests/slti.s
+++ b/src/test/riscv-tests/slti.s
@@ -215,9 +215,9 @@ test24:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/sltiu.s b/src/test/riscv-tests/sltiu.s
index 5564f56c..a8a27f25 100644
--- a/src/test/riscv-tests/sltiu.s
+++ b/src/test/riscv-tests/sltiu.s
@@ -215,9 +215,9 @@ test24:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/sltu.s b/src/test/riscv-tests/sltu.s
index 69afd293..a7654988 100644
--- a/src/test/riscv-tests/sltu.s
+++ b/src/test/riscv-tests/sltu.s
@@ -409,9 +409,9 @@ test37:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/sra.s b/src/test/riscv-tests/sra.s
index 6c0830cc..b5a71dd9 100644
--- a/src/test/riscv-tests/sra.s
+++ b/src/test/riscv-tests/sra.s
@@ -449,9 +449,9 @@ test42:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/srai.s b/src/test/riscv-tests/srai.s
index b08206f9..f96fc22a 100644
--- a/src/test/riscv-tests/srai.s
+++ b/src/test/riscv-tests/srai.s
@@ -215,9 +215,9 @@ test24:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/srl.s b/src/test/riscv-tests/srl.s
index c201ea08..7566960a 100644
--- a/src/test/riscv-tests/srl.s
+++ b/src/test/riscv-tests/srl.s
@@ -449,9 +449,9 @@ test42:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/srli.s b/src/test/riscv-tests/srli.s
index 3d00e0cc..b02de7d3 100644
--- a/src/test/riscv-tests/srli.s
+++ b/src/test/riscv-tests/srli.s
@@ -215,9 +215,9 @@ test24:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/sub.s b/src/test/riscv-tests/sub.s
index 9b603c9b..bec61b4a 100644
--- a/src/test/riscv-tests/sub.s
+++ b/src/test/riscv-tests/sub.s
@@ -401,9 +401,9 @@ test36:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/sw.s b/src/test/riscv-tests/sw.s
index 1678dc94..abda870d 100644
--- a/src/test/riscv-tests/sw.s
+++ b/src/test/riscv-tests/sw.s
@@ -300,9 +300,9 @@ label1_test22:
   bne x4, x5, label1_test22
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/xor.s b/src/test/riscv-tests/xor.s
index 4014ac7a..9c539200 100644
--- a/src/test/riscv-tests/xor.s
+++ b/src/test/riscv-tests/xor.s
@@ -321,9 +321,9 @@ test26:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall
diff --git a/src/test/riscv-tests/xori.s b/src/test/riscv-tests/xori.s
index 83678167..dfa950f9 100644
--- a/src/test/riscv-tests/xori.s
+++ b/src/test/riscv-tests/xori.s
@@ -138,9 +138,9 @@ test13:
   bne x0, x29, fail
 
 success:
-  li a0, 10
+  li a7, 10
   ecall
 
 fail:
-  li a0, 17
+  li a7, 17
   ecall