diff --git a/src/libultra/io/devmgr.c b/src/libultra/io/devmgr.c
index a40c8c14f9..168ca9b8df 100644
--- a/src/libultra/io/devmgr.c
+++ b/src/libultra/io/devmgr.c
@@ -36,7 +36,7 @@ void __osDevMgrMain(void* arg) {
 
             osRecvMesg(devMgr->acsQueue, &sp6C, OS_MESG_BLOCK);
             __osResetGlobalIntMask(OS_IM_PI);
-            __osEPiRawWriteIo(ioMesg->piHandle, LEO_BM_CTL, transfer->bmCtlShadow | 0x80000000);
+            __osEPiRawWriteIo(ioMesg->piHandle, LEO_BM_CTL, transfer->bmCtlShadow | LEO_BM_CTL_START);
 
         readblock1:
             osRecvMesg(devMgr->evtQueue, &sp70, OS_MESG_BLOCK);
diff --git a/src/libultra/io/viblack.c b/src/libultra/io/viblack.c
index 8b780d5389..60f62aec1c 100644
--- a/src/libultra/io/viblack.c
+++ b/src/libultra/io/viblack.c
@@ -1,9 +1,7 @@
 #include "ultra64.h"
 
 void osViBlack(u8 active) {
-    register u32 saveMask;
-
-    saveMask = __osDisableInt();
+    register u32 saveMask = __osDisableInt();
 
     if (active) {
         __osViNext->state |= VI_STATE_BLACK;
diff --git a/src/libultra/io/vigetnextframebuf.c b/src/libultra/io/vigetnextframebuf.c
index 7e87c5f33d..af6fb3179b 100644
--- a/src/libultra/io/vigetnextframebuf.c
+++ b/src/libultra/io/vigetnextframebuf.c
@@ -1,11 +1,9 @@
 #include "ultra64.h"
 
 void* osViGetNextFramebuffer(void) {
-    register u32 saveMask;
+    register u32 saveMask = __osDisableInt();
     void* buffer;
 
-    saveMask = __osDisableInt();
-
     buffer = __osViNext->buffer;
 
     __osRestoreInt(saveMask);
diff --git a/src/libultra/io/visetmode.c b/src/libultra/io/visetmode.c
index 0e21f9a94a..6117b06a2b 100644
--- a/src/libultra/io/visetmode.c
+++ b/src/libultra/io/visetmode.c
@@ -1,9 +1,7 @@
 #include "ultra64.h"
 
 void osViSetMode(OSViMode* modep) {
-    register u32 saveMask;
-
-    saveMask = __osDisableInt();
+    register u32 saveMask = __osDisableInt();
 
     __osViNext->modep = modep;
     __osViNext->state = VI_STATE_MODE_UPDATED;
diff --git a/src/libultra/io/visetxscale.c b/src/libultra/io/visetxscale.c
index 2a403cffd7..94f192b879 100644
--- a/src/libultra/io/visetxscale.c
+++ b/src/libultra/io/visetxscale.c
@@ -2,9 +2,7 @@
 
 void osViSetXScale(f32 value) {
     register u32 nomValue;
-    register u32 saveMask;
-
-    saveMask = __osDisableInt();
+    register u32 saveMask = __osDisableInt();
 
     __osViNext->x.factor = value;
 
diff --git a/src/libultra/io/visetyscale.c b/src/libultra/io/visetyscale.c
index 0c4b734ba8..093a61fa92 100644
--- a/src/libultra/io/visetyscale.c
+++ b/src/libultra/io/visetyscale.c
@@ -1,9 +1,7 @@
 #include "ultra64.h"
 
 void osViSetYScale(f32 value) {
-    register u32 saveMask;
-
-    saveMask = __osDisableInt();
+    register u32 saveMask = __osDisableInt();
 
     __osViNext->y.factor = value;
 
diff --git a/src/libultra/io/viswapcontext.c b/src/libultra/io/viswapcontext.c
index 0840ce7497..b6e9a8c5f1 100644
--- a/src/libultra/io/viswapcontext.c
+++ b/src/libultra/io/viswapcontext.c
@@ -8,14 +8,12 @@ void __osViSwapContext(void) {
     u32 vstart;
     u32 sp34;
     u32 field;
-    register u32 s2;
 
     field = 0;
     viNext = __osViNext;
     viMode = viNext->modep;
     field = IO_READ(VI_V_CURRENT_LINE_REG) & 1;
-    s2 = osVirtualToPhysical(viNext->buffer);
-    origin = (viMode->fldRegs[field].origin) + s2;
+    origin = osVirtualToPhysical(viNext->buffer) + viMode->fldRegs[field].origin;
     if (viNext->state & VI_STATE_XSCALE_UPDATED) {
         viNext->x.scale |= viMode->comRegs.xScale & ~0xFFF;
     } else {
diff --git a/src/libultra/os/destroythread.c b/src/libultra/os/destroythread.c
index d86a4db6e2..4bb7c9f34d 100644
--- a/src/libultra/os/destroythread.c
+++ b/src/libultra/os/destroythread.c
@@ -1,12 +1,10 @@
 #include "ultra64.h"
 
 void osDestroyThread(OSThread* t) {
-    register u32 saveMask;
+    register u32 saveMask = __osDisableInt();
     register OSThread* pred;
     register OSThread* succ;
 
-    saveMask = __osDisableInt();
-
     if (t == NULL) {
         t = __osRunningThread;
     } else if (t->state != OS_STATE_STOPPED) {
diff --git a/src/libultra/os/jammesg.c b/src/libultra/os/jammesg.c
index 83df63ee96..0baddad1c9 100644
--- a/src/libultra/os/jammesg.c
+++ b/src/libultra/os/jammesg.c
@@ -1,9 +1,7 @@
 #include "ultra64.h"
 
 s32 osJamMesg(OSMesgQueue* mq, OSMesg msg, s32 flag) {
-    register u32 saveMask;
-
-    saveMask = __osDisableInt();
+    register u32 saveMask = __osDisableInt();
 
     while (mq->validCount >= mq->msgCount) {
         if (flag == OS_MESG_BLOCK) {
diff --git a/src/libultra/os/sendmesg.c b/src/libultra/os/sendmesg.c
index bf8166e401..b2ab181095 100644
--- a/src/libultra/os/sendmesg.c
+++ b/src/libultra/os/sendmesg.c
@@ -1,11 +1,9 @@
 #include "ultra64.h"
 
 s32 osSendMesg(OSMesgQueue* mq, OSMesg msg, s32 flags) {
-    register u32 saveMask;
+    register u32 saveMask = __osDisableInt();
     register s32 last;
 
-    saveMask = __osDisableInt();
-
     while (MQ_IS_FULL(mq)) {
         if (flags == OS_MESG_BLOCK) {
             __osRunningThread->state = OS_STATE_WAITING;
diff --git a/src/libultra/os/seteventmesg.c b/src/libultra/os/seteventmesg.c
index b238372530..6f4fb0f97f 100644
--- a/src/libultra/os/seteventmesg.c
+++ b/src/libultra/os/seteventmesg.c
@@ -8,11 +8,9 @@ u32 __osPreNMI = false;
 __OSEventState __osEventStateTab[OS_NUM_EVENTS] ALIGNED(8);
 
 void osSetEventMesg(OSEvent e, OSMesgQueue* mq, OSMesg m) {
-    register u32 saveMask;
+    register u32 saveMask = __osDisableInt();
     __OSEventState* es;
 
-    saveMask = __osDisableInt();
-
     es = &__osEventStateTab[e];
 
     es->messageQueue = mq;
diff --git a/src/libultra/os/setthreadpri.c b/src/libultra/os/setthreadpri.c
index 0a6f3e356d..39ec0d159c 100644
--- a/src/libultra/os/setthreadpri.c
+++ b/src/libultra/os/setthreadpri.c
@@ -1,9 +1,7 @@
 #include "ultra64.h"
 
 void osSetThreadPri(OSThread* thread, OSPri p) {
-    register u32 saveMask;
-
-    saveMask = __osDisableInt();
+    register u32 saveMask = __osDisableInt();
 
     if (thread == NULL) {
         thread = __osRunningThread;