diff --git a/kinclude/csr.c b/kinclude/csr.c
index 6ac05b8..87f173e 100644
--- a/kinclude/csr.c
+++ b/kinclude/csr.c
@@ -8,10 +8,10 @@
 
 void write_mtimecmp(unsigned long long int mtimecmp)
 {
-    unsigned int lo = mtimecmp;
+    unsigned int lo = mtimecmp & 0xffffffff;
     unsigned int hi = mtimecmp >> 32;
 
-    __asm__ (
+    __asm__ volatile(
          "li t0, %0\n"
          "sw %1, 0(t0)\n"
          "sw %2, 4(t0)" ::
@@ -23,10 +23,10 @@ void write_mtimecmp(unsigned long long int mtimecmp)
 
 void write_mtimecmp(unsigned long long int mtimecmp)
 {
-    unsigned int lower = mtimecmp;
+    unsigned int lower = mtimecmp & 0xffffffff;
     unsigned int higher = mtimecmp >> 32;
 
-    __asm__ (
+    __asm__ volatile(
          "csrw %0, %2\n"
          "csrw %1, %3" ::
          "I"(CSR_MTIMECMP),"I"(CSR_MTIMECMPH),
diff --git a/kinclude/csr.h b/kinclude/csr.h
index 7d9dd5e..e8b94a3 100644
--- a/kinclude/csr.h
+++ b/kinclude/csr.h
@@ -41,7 +41,7 @@ inline __attribute__((always_inline)) unsigned long long int read_time()
 {
     unsigned int lower, higher;
 
-    __asm__ (
+    __asm__ volatile(
          "csrr %0, %2\n"
          "csrr %1, %3\n"
          : "=r"(lower), "=r"(higher)
diff --git a/kinclude/ecall.c b/kinclude/ecall.c
index 98e3ced..ddb7e31 100644
--- a/kinclude/ecall.c
+++ b/kinclude/ecall.c
@@ -131,8 +131,8 @@ void trap_handle_ecall()
         // run the corresponding ecall handler
         optional_int handler_result = ecall_table[code](&regs[REG_A0], pcb);
         // populate registers with return value and error
-        regs[REG_A0] = handler_result.value;
-        regs[REG_A0 + 1] = handler_result.error;
+        regs[REG_A0] = handler_result.error;
+        regs[REG_A0 + 1] = handler_result.value;
     }
 
     // increment pc of this process to move past ecall instruction
diff --git a/kinclude/ktypes.h b/kinclude/ktypes.h
index f67edc8..5bb6b8a 100644
--- a/kinclude/ktypes.h
+++ b/kinclude/ktypes.h
@@ -124,6 +124,10 @@ struct voidptr_stack {
     int size;
 };
 
+inline void* voidptr_stack_pop(struct voidptr_stack* stack) __attribute__((always_inline));
+inline int voidptr_stack_push(struct voidptr_stack* stack, void* ptr) __attribute__((always_inline));
+inline void voidptr_stack_new(struct voidptr_stack* stack, void** data, int size) __attribute__((always_inline));
+
 inline void* voidptr_stack_pop(struct voidptr_stack* stack)
 {
     if (stack->pos == -1)
diff --git a/kinclude/malloc.c b/kinclude/malloc.c
index 89f1997..e275f01 100644
--- a/kinclude/malloc.c
+++ b/kinclude/malloc.c
@@ -1,4 +1,5 @@
 #include "../kernel.h"
+#include "ktypes.h"
 #include "malloc.h"
 #include "ecall.h"
 #include "io.h"
diff --git a/kinclude/sched.c b/kinclude/sched.c
index 89cb29a..0c8ff51 100644
--- a/kinclude/sched.c
+++ b/kinclude/sched.c
@@ -95,8 +95,8 @@ struct process_control_block* scheduler_select_free()
                 if (pcb->waiting_for_process != NULL &&
                     pcb->waiting_for_process->status == PROC_DEAD) {
                     // the requested process exited, so we can set the status code and
-                    pcb->regs[REG_A0] = pcb->waiting_for_process->exit_code;
-                    pcb->regs[REG_A0 + 1] = 0;
+                    pcb->regs[REG_A0] = 0;
+                    pcb->regs[REG_A0 + 1] = pcb->waiting_for_process->exit_code;
                     pcb->status = PROC_RDY;
                     return pcb;
                 }