Memstuff (#1164)

* Un-fake a couple of matches in memory manip functions

* Document fmodf

* Un-fake a couple of matches in memory manip functions

* Document fmodf

* Rename functions and files

* Document memmove, memsets, memcpys

* Format

* Sort out some missing sizeofs

* Name fmodf

* Rename local variables

* size_t

* Use COBRA_SHADOW_TEX_SIZE

* Review

* Tweak the Doxyfile to remove @brief requirement

* Roman's review

* Fix a bug comment

* Change fmodf

23 files changed, 288 insertions, 214 deletions

diff --git a/Doxyfile b/Doxyfile
index 8d98f6bf9..08b276377 100644
--- a/Doxyfile
+++ b/Doxyfile
@@ -187,7 +187,7 @@ SHORT_NAMES            = NO
 # description.)
 # The default value is: NO.
 
-JAVADOC_AUTOBRIEF      = NO
+JAVADOC_AUTOBRIEF      = YES
 
 # If the QT_AUTOBRIEF tag is set to YES then doxygen will interpret the first
 # line (until the first dot) of a Qt-style comment as the brief description. If
diff --git a/Makefile b/Makefile
index bc09cee21..71d707cec 100644
--- a/Makefile
+++ b/Makefile
@@ -192,9 +192,9 @@ build/src/code/fault.o: OPTFLAGS := -O2 -g3
 build/src/code/fault_drawer.o: CFLAGS += -trapuv
 build/src/code/fault_drawer.o: OPTFLAGS := -O2 -g3
 build/src/code/ucode_disas.o: OPTFLAGS := -O2 -g3
-build/src/code/code_801068B0.o: OPTFLAGS := -g
-build/src/code/code_80106860.o: OPTFLAGS := -g
 build/src/code/fmodf.o: OPTFLAGS := -g
+build/src/code/__osMemset.o: OPTFLAGS := -g
+build/src/code/__osMemmove.o: OPTFLAGS := -g
 
 build/src/libultra/libc/absf.o: OPTFLAGS := -O2 -g3
 build/src/libultra/libc/sqrt.o: OPTFLAGS := -O2 -g3
diff --git a/include/functions.h b/include/functions.h
index 7387e3b70..d19313603 100644
--- a/include/functions.h
+++ b/include/functions.h
@@ -114,7 +114,7 @@ void osUnmapTLBAll(void);
 s32 osEPiStartDma(OSPiHandle* handle, OSIoMesg* mb, s32 direction);
 const char* strchr(const char* str, s32 ch);
 u32 strlen(const char* str);
-void* memcpy(void* dst, const void* src, u32 size);
+void* memcpy(void* dst, const void* src, size_t size);
 void osInvalICache(void* vaddr, s32 nbytes);
 void osCreateMesgQueue(OSMesgQueue* mq, OSMesg* msg, s32 count);
 void osInvalDCache(void* vaddr, s32 nbytes);
@@ -828,7 +828,7 @@ void func_800645A0(GlobalContext* globalCtx, CutsceneContext* csCtx);
 void Cutscene_HandleEntranceTriggers(GlobalContext* globalCtx);
 void Cutscene_HandleConditionalTriggers(GlobalContext* globalCtx);
 void Cutscene_SetSegment(GlobalContext* globalCtx, void* segment);
-void* MemCopy(void* dest, void* src, s32 size);
+void* MemCpy(void* dest, const void* src, s32 len);
 void GetItem_Draw(GlobalContext* globalCtx, s16 drawId);
 void SoundSource_InitAll(GlobalContext* globalCtx);
 void SoundSource_UpdateAll(GlobalContext* globalCtx);
@@ -907,7 +907,7 @@ s32 Environment_IsForcedSequenceDisabled(void);
 void Environment_PlayStormNatureAmbience(GlobalContext* globalCtx);
 void Environment_StopStormNatureAmbience(GlobalContext* globalCtx);
 void Environment_WarpSongLeave(GlobalContext* globalCtx);
-void Lib_MemSet(u8* dest, size_t size, u8 val);
+void Lib_MemSet(u8* dest, size_t len, u8 val);
 f32 Math_CosS(s16 angle);
 f32 Math_SinS(s16 angle);
 s32 Math_ScaledStepToS(s16* pValue, s16 target, s16 step);
@@ -2278,8 +2278,8 @@ void guMtxF2L(MtxF* m1, Mtx* m2);
 u32* osViGetCurrentFramebuffer(void);
 s32 __osSpSetPc(void* pc);
 f32 absf(f32);
-void* func_80106860(void* ptr, s32 val, size_t size);
-void* func_801068B0(void* dst, void* src, size_t size);
+void* __osMemset(void* dest, s32 val, size_t len);
+void* __osMemmove(void* dest, const void* src, size_t len);
 void Message_UpdateOcarinaGame(GlobalContext* globalCtx);
 u8 Message_ShouldAdvance(GlobalContext* globalCtx);
 void Message_CloseTextbox(GlobalContext*);
diff --git a/spec b/spec
index a136ce2e4..8573f3510 100644
--- a/spec
+++ b/spec
@@ -510,8 +510,8 @@ beginseg
     include "build/src/libultra/libc/sqrt.o"
     include "build/src/libultra/libc/absf.o"
     include "build/src/code/fmodf.o"
-    include "build/src/code/code_80106860.o"
-    include "build/src/code/code_801068B0.o"
+    include "build/src/code/__osMemset.o"
+    include "build/src/code/__osMemmove.o"
     include_data_with_rodata "build/src/code/z_message_PAL.o"
     include "build/src/code/z_game_over.o"
     include "build/src/code/z_construct.o"
diff --git a/src/code/__osMalloc.c b/src/code/__osMalloc.c
index ddf3024fa..30e99cecb 100644
--- a/src/code/__osMalloc.c
+++ b/src/code/__osMalloc.c
@@ -122,7 +122,7 @@ void __osMallocAddBlock(Arena* arena, void* start, s32 size) {
         size2 = (size - diff) & ~0xF;
 
         if (size2 > (s32)sizeof(ArenaNode)) {
-            func_80106860(firstNode, BLOCK_UNINIT_MAGIC, size2); // memset
+            __osMemset(firstNode, BLOCK_UNINIT_MAGIC, size2);
             firstNode->next = NULL;
             firstNode->prev = NULL;
             firstNode->size = size2 - sizeof(ArenaNode);
@@ -151,7 +151,7 @@ void ArenaImpl_RemoveAllBlocks(Arena* arena) {
     iter = arena->head;
     while (iter != NULL) {
         next = ArenaImpl_GetNextBlock(iter);
-        func_80106860(iter, BLOCK_UNINIT_MAGIC, iter->size + sizeof(ArenaNode)); // memset
+        __osMemset(iter, BLOCK_UNINIT_MAGIC, iter->size + sizeof(ArenaNode));
         iter = next;
     }
 
@@ -228,7 +228,7 @@ void* __osMalloc_NoLockDebug(Arena* arena, u32 size, const char* file, s32 line)
             ArenaImpl_SetDebugInfo(iter, file, line, arena);
             alloc = (void*)((u32)iter + sizeof(ArenaNode));
             if (arena->flag & FILL_ALLOCBLOCK) {
-                func_80106860(alloc, BLOCK_ALLOC_MAGIC, size);
+                __osMemset(alloc, BLOCK_ALLOC_MAGIC, size);
             }
 
             break;
@@ -288,7 +288,7 @@ void* __osMallocRDebug(Arena* arena, u32 size, const char* file, s32 line) {
             ArenaImpl_SetDebugInfo(iter, file, line, arena);
             allocR = (void*)((u32)iter + sizeof(ArenaNode));
             if (arena->flag & FILL_ALLOCBLOCK) {
-                func_80106860(allocR, BLOCK_ALLOC_MAGIC, size);
+                __osMemset(allocR, BLOCK_ALLOC_MAGIC, size);
             }
 
             break;
@@ -339,7 +339,7 @@ void* __osMalloc_NoLock(Arena* arena, u32 size) {
             ArenaImpl_SetDebugInfo(iter, NULL, 0, arena);
             alloc = (void*)((u32)iter + sizeof(ArenaNode));
             if (arena->flag & FILL_ALLOCBLOCK) {
-                func_80106860(alloc, BLOCK_ALLOC_MAGIC, size);
+                __osMemset(alloc, BLOCK_ALLOC_MAGIC, size);
             }
             break;
         }
@@ -398,7 +398,7 @@ void* __osMallocR(Arena* arena, u32 size) {
             ArenaImpl_SetDebugInfo(iter, NULL, 0, arena);
             alloc = (void*)((u32)iter + sizeof(ArenaNode));
             if (arena->flag & FILL_ALLOCBLOCK) {
-                func_80106860(alloc, BLOCK_ALLOC_MAGIC, size);
+                __osMemset(alloc, BLOCK_ALLOC_MAGIC, size);
             }
             break;
         }
@@ -442,7 +442,7 @@ void __osFree_NoLock(Arena* arena, void* ptr) {
     ArenaImpl_SetDebugInfo(node, NULL, 0, arena);
 
     if (arena->flag & FILL_FREEBLOCK) {
-        func_80106860((u32)node + sizeof(ArenaNode), BLOCK_FREE_MAGIC, node->size);
+        __osMemset((u32)node + sizeof(ArenaNode), BLOCK_FREE_MAGIC, node->size);
     }
 
     newNext = next;
@@ -454,7 +454,7 @@ void __osFree_NoLock(Arena* arena, void* ptr) {
 
         node->size += next->size + sizeof(ArenaNode);
         if (arena->flag & FILL_FREEBLOCK) {
-            func_80106860(next, BLOCK_FREE_MAGIC, sizeof(ArenaNode));
+            __osMemset(next, BLOCK_FREE_MAGIC, sizeof(ArenaNode));
         }
         node->next = newNext;
         next = newNext;
@@ -467,7 +467,7 @@ void __osFree_NoLock(Arena* arena, void* ptr) {
         prev->next = next;
         prev->size += node->size + sizeof(ArenaNode);
         if (arena->flag & FILL_FREEBLOCK) {
-            func_80106860(node, BLOCK_FREE_MAGIC, sizeof(ArenaNode));
+            __osMemset(node, BLOCK_FREE_MAGIC, sizeof(ArenaNode));
         }
     }
 }
@@ -512,7 +512,7 @@ void __osFree_NoLockDebug(Arena* arena, void* ptr, const char* file, s32 line) {
     ArenaImpl_SetDebugInfo(node, file, line, arena);
 
     if (arena->flag & FILL_FREEBLOCK) {
-        func_80106860((u32)node + sizeof(ArenaNode), BLOCK_FREE_MAGIC, node->size);
+        __osMemset((u32)node + sizeof(ArenaNode), BLOCK_FREE_MAGIC, node->size);
     }
 
     newNext = node->next;
@@ -524,7 +524,7 @@ void __osFree_NoLockDebug(Arena* arena, void* ptr, const char* file, s32 line) {
 
         node->size += next->size + sizeof(ArenaNode);
         if (arena->flag & FILL_FREEBLOCK) {
-            func_80106860(next, BLOCK_FREE_MAGIC, sizeof(ArenaNode));
+            __osMemset(next, BLOCK_FREE_MAGIC, sizeof(ArenaNode));
         }
         node->next = newNext;
         next = newNext;
@@ -537,7 +537,7 @@ void __osFree_NoLockDebug(Arena* arena, void* ptr, const char* file, s32 line) {
         prev->next = next;
         prev->size += node->size + sizeof(ArenaNode);
         if (arena->flag & FILL_FREEBLOCK) {
-            func_80106860(node, BLOCK_FREE_MAGIC, sizeof(ArenaNode));
+            __osMemset(node, BLOCK_FREE_MAGIC, sizeof(ArenaNode));
         }
     }
 }
@@ -590,7 +590,7 @@ void* __osRealloc(Arena* arena, void* ptr, u32 newSize) {
                 }
                 node->next = newNext;
                 node->size = newSize;
-                func_801068B0(newNext, next, sizeof(ArenaNode)); // memcpy
+                __osMemmove(newNext, next, sizeof(ArenaNode));
             } else {
                 // "Allocate a new memory block and move the contents"
                 osSyncPrintf("新たにメモリブロックを確保して内容を移動します\n");
diff --git a/src/code/__osMemmove.c b/src/code/__osMemmove.c
new file mode 100644
index 000000000..892fee5ee
--- /dev/null
+++ b/src/code/__osMemmove.c
@@ -0,0 +1,33 @@
+#include "global.h"
+
+/**
+ * memmove: copies `len` bytes from memory starting at `src` to memory starting at `dest`.
+ *
+ * Unlike memcpy(), the regions of memory may overlap.
+ *
+ * @param dest address of start of buffer to write to
+ * @param src address of start of buffer to read from
+ * @param len number of bytes to copy.
+ *
+ * @return dest
+ */
+void* __osMemmove(void* dest, const void* src, size_t len) {
+    u8* d = dest;
+    const u8* s = src;
+
+    if (d == s) {
+        return dest;
+    }
+    if (d < s) {
+        while (len--) {
+            *d++ = *s++;
+        }
+    } else {
+        d += len - 1;
+        s += len - 1;
+        while (len--) {
+            *d-- = *s--;
+        }
+    }
+    return dest;
+}
diff --git a/src/code/__osMemset.c b/src/code/__osMemset.c
new file mode 100644
index 000000000..703d3a8c1
--- /dev/null
+++ b/src/code/__osMemset.c
@@ -0,0 +1,21 @@
+#include "global.h"
+
+/**
+ * memset: sets `len` bytes to `val` starting at address `dest`.
+ *
+ * @see There are two other memsets in this codebase, Lib_MemSet(), MemSet()
+ *
+ * @param dest address to start at
+ * @param val value to write (s32, but interpreted as u8)
+ * @param len number of bytes to write
+ *
+ * @return dest
+ */
+void* __osMemset(void* dest, s32 val, size_t len) {
+    u8* ptr = dest;
+
+    while (len--) {
+        *ptr++ = val;
+    }
+    return dest;
+}
diff --git a/src/code/audio_heap.c b/src/code/audio_heap.c
index 4ba1cff41..3dc51979c 100644
--- a/src/code/audio_heap.c
+++ b/src/code/audio_heap.c
@@ -1021,7 +1021,7 @@ void* AudioHeap_AllocPermanent(s32 tableType, s32 id, u32 size) {
     gAudioContext.permanentCache[index].size = size;
 
     //! @bug UB: missing return. "ret" is in v0 at this point, but doing an
-    // explicit return uses an additional register.
+    //! explicit return uses an additional register.
 #ifdef AVOID_UB
     return ret;
 #endif
diff --git a/src/code/code_80069420.c b/src/code/code_80069420.c
index 3d656cfb0..6dd0a94f4 100644
--- a/src/code/code_80069420.c
+++ b/src/code/code_80069420.c
@@ -1,23 +1,47 @@
 #include "global.h"
 
-void* MemCopy(void* dest, void* src, s32 size) {
-    u8* destu = (u8*)dest;
-    u8* srcu = (u8*)src;
+/**
+ * memcpy: copies `len` bytes from memory starting at `src` to memory starting at `dest`. Expects the memory
+ * specified by `src` and `dest` to not overlap.
+ *
+ * @see libultra also has a memcpy().
+ *
+ * @param dest address of start of buffer writing to
+ * @param src address of start of buffer to read from
+ * @param len number of bytes to copy. (`s32` rather than the standard `size_t`)
+ *
+ * @return dest
+ */
+void* MemCpy(void* dest, const void* src, s32 len) {
+    u8* d = dest;
+    const u8* s = src;
 
-    while (size > 0) {
-        *destu++ = *srcu++;
-        size--;
+    while (len > 0) {
+        *d++ = *s++;
+        len--;
     }
 
     return dest;
 }
 
-void* MemSet(void* dest, s32 val, s32 size) {
-    u8* destu = (u8*)dest;
-    s32 s = size;
+/**
+ * memset: sets `len` bytes to `val` starting at address `dest`.
+ *
+ * @see There are two other memsets in this codebase, Lib_MemSet(), __osMemset().
+ * This one is unused.
+ *
+ * @param dest address to start at
+ * @param val value to write (`s32`, but interpreted as `u8`)
+ * @param len number of bytes to write. (`s32` rather than the standard `size_t`)
+ *
+ * @return dest
+ */
+void* MemSet(void* dest, s32 val, s32 len) {
+    u8* d = dest;
+    s32 s = len;
 
     while (s > 0) {
-        *destu++ = val;
+        *d++ = val;
         s--;
     }
 
diff --git a/src/code/code_80106860.c b/src/code/code_80106860.c
deleted file mode 100644
index 4c1b8480b..000000000
--- a/src/code/code_80106860.c
+++ /dev/null
@@ -1,12 +0,0 @@
-#include "global.h"
-
-// memset used in __osMalloc, z_quake, z_view, and z_camera
-void* func_80106860(void* ptr, s32 val, size_t size) {
-    u8* sp4 = ptr;
-    register s32 a3;
-
-    for (a3 = size--; a3 != 0; a3 = size--) {
-        *sp4++ = val;
-    }
-    return ptr;
-}
diff --git a/src/code/code_801068B0.c b/src/code/code_801068B0.c
deleted file mode 100644
index d673cc5e0..000000000
--- a/src/code/code_801068B0.c
+++ /dev/null
@@ -1,24 +0,0 @@
-#include "global.h"
-
-// memmove used in __osMalloc.c
-void* func_801068B0(void* dst, void* src, size_t size) {
-    u8* spC = dst;
-    u8* sp8 = src;
-    register s32 a3;
-
-    if (spC == sp8) {
-        return dst;
-    }
-    if (spC < sp8) {
-        for (a3 = size--; a3 != 0; a3 = size--) {
-            *spC++ = *sp8++;
-        }
-    } else {
-        spC += size - 1;
-        sp8 += size - 1;
-        for (a3 = size--; a3 != 0; a3 = size--) {
-            *spC-- = *sp8--;
-        }
-    }
-    return dst;
-}
diff --git a/src/code/fmodf.c b/src/code/fmodf.c
index 6cc69dd87..e1e386223 100644
--- a/src/code/fmodf.c
+++ b/src/code/fmodf.c
@@ -1,12 +1,27 @@
 #include "global.h"
 
+/**
+ * Computes one `x` modulo `y` for floats.
+ *
+ * Acts like the standard C fmodf except does not handle Infinity. See https://en.cppreference.com/w/c/numeric/math/fmod
+ * for the details. It summarizes this function as follows:
+ * "The floating-point remainder of the division operation x/y calculated by this function is exactly the value x - n*y,
+ * where n is x/y with its fractional part truncated.
+ *
+ * The returned value has the same sign as x and is less or equal to y in magnitude."
+ *
+ * @param x dividend
+ * @param y modulus
+ *
+ * @return f32 0.0f if y is 0.0f, or x modulo y otherwise
+ */
 f32 fmodf(f32 x, f32 y) {
-    s32 quot;
+    s32 n;
 
     if (y == 0.0f) {
         return 0.0f;
     }
-    quot = x / y;
+    n = x / y;
 
-    return x - (quot * y);
+    return x - (n * y);
 }
diff --git a/src/code/z_camera.c b/src/code/z_camera.c
index 74af46b0f..cc2c65b54 100644
--- a/src/code/z_camera.c
+++ b/src/code/z_camera.c
@@ -6793,7 +6793,7 @@ void Camera_Init(Camera* camera, View* view, CollisionContext* colCtx, GlobalCon
     s16 curUID;
     s16 j;
 
-    func_80106860(camera, 0, sizeof(*camera));
+    __osMemset(camera, 0, sizeof(Camera));
     if (sInitRegs) {
         for (i = 0; i < sOREGInitCnt; i++) {
             OREG(i) = sOREGInit[i];
diff --git a/src/code/z_demo.c b/src/code/z_demo.c
index 3b6e42327..9e58d7b69 100644
--- a/src/code/z_demo.c
+++ b/src/code/z_demo.c
@@ -1571,9 +1571,9 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
     s32 cutsceneEndFrame;
     s16 j;
 
-    MemCopy(&totalEntries, cutscenePtr, 4);
+    MemCpy(&totalEntries, cutscenePtr, 4);
     cutscenePtr += 4;
-    MemCopy(&cutsceneEndFrame, cutscenePtr, 4);
+    MemCpy(&cutsceneEndFrame, cutscenePtr, 4);
     cutscenePtr += 4;
 
     if ((cutsceneEndFrame < csCtx->frames) && (csCtx->state != CS_STATE_UNSKIPPABLE_EXEC)) {
@@ -1587,7 +1587,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
     }
 
     for (i = 0; i < totalEntries; i++) {
-        MemCopy(&cmdType, cutscenePtr, 4);
+        MemCpy(&cmdType, cutscenePtr, 4);
         cutscenePtr += 4;
 
         if (cmdType == -1) {
@@ -1596,7 +1596,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
 
         switch (cmdType) {
             case CS_CMD_MISC:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     func_80064824(globalCtx, csCtx, (void*)cutscenePtr);
@@ -1604,7 +1604,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
                 }
                 break;
             case CS_CMD_SET_LIGHTING:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     Cutscene_Command_SetLighting(globalCtx, csCtx, (void*)cutscenePtr);
@@ -1612,7 +1612,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
                 }
                 break;
             case CS_CMD_PLAYBGM:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     Cutscene_Command_PlayBGM(globalCtx, csCtx, (void*)cutscenePtr);
@@ -1620,7 +1620,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
                 }
                 break;
             case CS_CMD_STOPBGM:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     Cutscene_Command_StopBGM(globalCtx, csCtx, (void*)cutscenePtr);
@@ -1628,7 +1628,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
                 }
                 break;
             case CS_CMD_FADEBGM:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     Cutscene_Command_FadeBGM(globalCtx, csCtx, (void*)cutscenePtr);
@@ -1636,7 +1636,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
                 }
                 break;
             case CS_CMD_09:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     Cutscene_Command_09(globalCtx, csCtx, (void*)cutscenePtr);
@@ -1644,7 +1644,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
                 }
                 break;
             case CS_CMD_SETTIME:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     func_80065134(globalCtx, csCtx, (void*)cutscenePtr);
@@ -1652,7 +1652,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
                 }
                 break;
             case CS_CMD_SET_PLAYER_ACTION:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     cmd = (CsCmdBase*)cutscenePtr;
@@ -1680,7 +1680,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
             case 138:
             case 139:
             case 144:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     cmd = (CsCmdBase*)cutscenePtr;
@@ -1708,7 +1708,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
             case 125:
             case 131:
             case 141:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     cmd = (CsCmdBase*)cutscenePtr;
@@ -1732,7 +1732,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
             case 121:
             case 126:
             case 132:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     cmd = (CsCmdBase*)cutscenePtr;
@@ -1755,7 +1755,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
             case 108:
             case 127:
             case 133:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     cmd = (CsCmdBase*)cutscenePtr;
@@ -1774,7 +1774,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
             case 83:
             case 128:
             case 135:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     cmd = (CsCmdBase*)cutscenePtr;
@@ -1791,7 +1791,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
             case 90:
             case 129:
             case 136:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     cmd = (CsCmdBase*)cutscenePtr;
@@ -1809,7 +1809,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
             case 115:
             case 130:
             case 137:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     cmd = (CsCmdBase*)cutscenePtr;
@@ -1826,7 +1826,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
             case 114:
             case 134:
             case 142:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     cmd = (CsCmdBase*)cutscenePtr;
@@ -1837,7 +1837,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
                 }
                 break;
             case CS_CMD_SET_ACTOR_ACTION_9:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     cmd = (CsCmdBase*)cutscenePtr;
@@ -1848,7 +1848,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
                 }
                 break;
             case CS_CMD_SET_ACTOR_ACTION_10:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     cmd = (CsCmdBase*)cutscenePtr;
@@ -1882,7 +1882,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
                 cutscenePtr += 8;
                 break;
             case CS_CMD_TEXTBOX:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     cmd = (CsCmdBase*)cutscenePtr;
@@ -1898,7 +1898,7 @@ void Cutscene_ProcessCommands(GlobalContext* globalCtx, CutsceneContext* csCtx,
                 cutscenePtr += 8;
                 break;
             default:
-                MemCopy(&cmdEntries, cutscenePtr, 4);
+                MemCpy(&cmdEntries, cutscenePtr, 4);
                 cutscenePtr += 4;
                 for (j = 0; j < cmdEntries; j++) {
                     cutscenePtr += 0x30;
diff --git a/src/code/z_lib.c b/src/code/z_lib.c
index 90df45b91..524d58a0a 100644
--- a/src/code/z_lib.c
+++ b/src/code/z_lib.c
@@ -1,10 +1,25 @@
 #include "global.h"
 
-void Lib_MemSet(u8* dest, size_t size, u8 val) {
-    u32 i;
+/**
+ * memset: sets `len` bytes to `val` starting at address `dest`.
+ *
+ * Unlike normal memset,
+ * - `dest` is a `u8*` already,
+ * - does not return `dest`,
+ * - the arguments are in a different order,
+ * - `val` is a `u8` instead of the standard `s32`.
+ *
+ * @see There are two other memsets in this codebase, __osMemset(), MemSet()
+ *
+ * @param dest address to start at
+ * @param len number of bytes to write
+ * @param val value to write
+ */
+void Lib_MemSet(u8* dest, size_t len, u8 val) {
+    size_t i;
 
     // clang-format off
-    for (i = 0; i < size; i++) { *dest++ = val; }
+    for (i = 0; i < len; i++) { *dest++ = val; }
     // clang-format on
 }
 
diff --git a/src/code/z_message_PAL.c b/src/code/z_message_PAL.c
index c5b316f46..eb5320926 100644
--- a/src/code/z_message_PAL.c
+++ b/src/code/z_message_PAL.c
@@ -2619,8 +2619,8 @@ void Message_DrawMain(GlobalContext* globalCtx, Gfx** p) {
                     osSyncPrintf("録音終了！！！！！！！！！録音終了\n");
                     osSyncPrintf(VT_FGCOL(YELLOW));
                     osSyncPrintf("\n====================================================================\n");
-                    MemCopy(gSaveContext.scarecrowCustomSong, gScarecrowCustomSongPtr,
-                            sizeof(gSaveContext.scarecrowCustomSong));
+                    MemCpy(gSaveContext.scarecrowCustomSong, gScarecrowCustomSongPtr,
+                           sizeof(gSaveContext.scarecrowCustomSong));
                     for (i = 0; i < ARRAY_COUNT(gSaveContext.scarecrowCustomSong); i++) {
                         osSyncPrintf("%d, ", gSaveContext.scarecrowCustomSong[i]);
                     }
@@ -2682,8 +2682,8 @@ void Message_DrawMain(GlobalContext* globalCtx, Gfx** p) {
                                            &gSfxDefaultFreqAndVolScale, &gSfxDefaultReverb);
                     osSyncPrintf(VT_FGCOL(YELLOW));
                     osSyncPrintf("\n====================================================================\n");
-                    MemCopy(gSaveContext.scarecrowSpawnSong, gScarecrowSpawnSongPtr,
-                            sizeof(gSaveContext.scarecrowSpawnSong));
+                    MemCpy(gSaveContext.scarecrowSpawnSong, gScarecrowSpawnSongPtr,
+                           sizeof(gSaveContext.scarecrowSpawnSong));
                     for (i = 0; i < ARRAY_COUNT(gSaveContext.scarecrowSpawnSong); i++) {
                         osSyncPrintf("%d, ", gSaveContext.scarecrowSpawnSong[i]);
                     }
diff --git a/src/code/z_quake.c b/src/code/z_quake.c
index cd1fac1d1..257d6627b 100644
--- a/src/code/z_quake.c
+++ b/src/code/z_quake.c
@@ -152,7 +152,7 @@ QuakeRequest* Quake_AddImpl(Camera* cam, u32 callbackIdx) {
     s16 idx = Quake_GetFreeIndex();
     QuakeRequest* req = &sQuakeRequest[idx];
 
-    func_80106860(req, 0, sizeof(QuakeRequest)); // memset
+    __osMemset(req, 0, sizeof(QuakeRequest));
     req->cam = cam;
     req->camPtrIdx = cam->thisIdx;
     req->callbackIdx = callbackIdx;
diff --git a/src/code/z_sram.c b/src/code/z_sram.c
index 923f7d5b1..1277b06ea 100644
--- a/src/code/z_sram.c
+++ b/src/code/z_sram.c
@@ -322,7 +322,7 @@ void Sram_OpenSave(SramContext* sramCtx) {
     i = gSramSlotOffsets[gSaveContext.fileNum];
     osSyncPrintf("ぽいんと＝%x(%d)\n", i, gSaveContext.fileNum); // "Point="
 
-    MemCopy(&gSaveContext, sramCtx->readBuff + i, sizeof(Save));
+    MemCpy(&gSaveContext, sramCtx->readBuff + i, sizeof(Save));
 
     osSyncPrintf(VT_FGCOL(YELLOW));
     osSyncPrintf("SCENE_DATA_ID = %d   SceneNo = %d\n", gSaveContext.savedSceneNum,
@@ -397,7 +397,7 @@ void Sram_OpenSave(SramContext* sramCtx) {
         osSyncPrintf(VT_FGCOL(BLUE));
         osSyncPrintf("\n====================================================================\n");
 
-        MemCopy(gScarecrowCustomSongPtr, gSaveContext.scarecrowCustomSong, sizeof(gSaveContext.scarecrowCustomSong));
+        MemCpy(gScarecrowCustomSongPtr, gSaveContext.scarecrowCustomSong, sizeof(gSaveContext.scarecrowCustomSong));
 
         ptr = (u8*)gScarecrowCustomSongPtr;
         for (i = 0; i < ARRAY_COUNT(gSaveContext.scarecrowCustomSong); i++, ptr++) {
@@ -412,7 +412,7 @@ void Sram_OpenSave(SramContext* sramCtx) {
         osSyncPrintf(VT_FGCOL(GREEN));
         osSyncPrintf("\n====================================================================\n");
 
-        MemCopy(gScarecrowSpawnSongPtr, gSaveContext.scarecrowSpawnSong, sizeof(gSaveContext.scarecrowSpawnSong));
+        MemCpy(gScarecrowSpawnSongPtr, gSaveContext.scarecrowSpawnSong, sizeof(gSaveContext.scarecrowSpawnSong));
 
         ptr = gScarecrowSpawnSongPtr;
         for (i = 0; i < ARRAY_COUNT(gSaveContext.scarecrowSpawnSong); i++, ptr++) {
@@ -537,7 +537,7 @@ void Sram_VerifyAndLoadAllSaves(FileChooseContext* fileChooseCtx, SramContext* s
     for (slotNum = 0; slotNum < 3; slotNum++) {
         offset = gSramSlotOffsets[slotNum];
         osSyncPrintf("ぽいんと＝%x(%d)    SAVE_MAX=%d\n", offset, gSaveContext.fileNum, sizeof(Save));
-        MemCopy(&gSaveContext, sramCtx->readBuff + offset, sizeof(Save));
+        MemCpy(&gSaveContext, sramCtx->readBuff + offset, sizeof(Save));
 
         oldChecksum = gSaveContext.checksum;
         gSaveContext.checksum = 0;
@@ -555,7 +555,7 @@ void Sram_VerifyAndLoadAllSaves(FileChooseContext* fileChooseCtx, SramContext* s
             // checksum didnt match, try backup save
             osSyncPrintf("ＥＲＲＯＲ！！！ ＝ %x(%d)\n", gSramSlotOffsets[slotNum], slotNum);
             offset = gSramSlotOffsets[slotNum + 3];
-            MemCopy(&gSaveContext, sramCtx->readBuff + offset, sizeof(Save));
+            MemCpy(&gSaveContext, sramCtx->readBuff + offset, sizeof(Save));
 
             oldChecksum = gSaveContext.checksum;
             gSaveContext.checksum = 0;
@@ -635,48 +635,45 @@ void Sram_VerifyAndLoadAllSaves(FileChooseContext* fileChooseCtx, SramContext* s
     osSyncPrintf("SAVECT=%x, NAME=%x, LIFE=%x, ITEM=%x,  64DD=%x,  HEART=%x\n", DEATHS, NAME, HEALTH_CAP, QUEST, N64DD,
                  DEFENSE);
 
-    MemCopy(&fileChooseCtx->deaths[0], sramCtx->readBuff + SLOT_OFFSET(0) + DEATHS, sizeof(fileChooseCtx->deaths[0]));
-    MemCopy(&fileChooseCtx->deaths[1], sramCtx->readBuff + SLOT_OFFSET(1) + DEATHS, sizeof(fileChooseCtx->deaths[0]));
-    MemCopy(&fileChooseCtx->deaths[2], sramCtx->readBuff + SLOT_OFFSET(2) + DEATHS, sizeof(fileChooseCtx->deaths[0]));
-
-    MemCopy(&fileChooseCtx->fileNames[0], sramCtx->readBuff + SLOT_OFFSET(0) + NAME,
-            sizeof(fileChooseCtx->fileNames[0]));
-    MemCopy(&fileChooseCtx->fileNames[1], sramCtx->readBuff + SLOT_OFFSET(1) + NAME,
-            sizeof(fileChooseCtx->fileNames[0]));
-    MemCopy(&fileChooseCtx->fileNames[2], sramCtx->readBuff + SLOT_OFFSET(2) + NAME,
-            sizeof(fileChooseCtx->fileNames[0]));
-
-    MemCopy(&fileChooseCtx->healthCapacities[0], sramCtx->readBuff + SLOT_OFFSET(0) + HEALTH_CAP,
-            sizeof(fileChooseCtx->healthCapacities[0]));
-    MemCopy(&fileChooseCtx->healthCapacities[1], sramCtx->readBuff + SLOT_OFFSET(1) + HEALTH_CAP,
-            sizeof(fileChooseCtx->healthCapacities[0]));
-    MemCopy(&fileChooseCtx->healthCapacities[2], sramCtx->readBuff + SLOT_OFFSET(2) + HEALTH_CAP,
-            sizeof(fileChooseCtx->healthCapacities[0]));
-
-    MemCopy(&fileChooseCtx->questItems[0], sramCtx->readBuff + SLOT_OFFSET(0) + QUEST,
-            sizeof(fileChooseCtx->questItems[0]));
-    MemCopy(&fileChooseCtx->questItems[1], sramCtx->readBuff + SLOT_OFFSET(1) + QUEST,
-            sizeof(fileChooseCtx->questItems[0]));
-    MemCopy(&fileChooseCtx->questItems[2], sramCtx->readBuff + SLOT_OFFSET(2) + QUEST,
-            sizeof(fileChooseCtx->questItems[0]));
-
-    MemCopy(&fileChooseCtx->n64ddFlags[0], sramCtx->readBuff + SLOT_OFFSET(0) + N64DD,
-            sizeof(fileChooseCtx->n64ddFlags[0]));
-    MemCopy(&fileChooseCtx->n64ddFlags[1], sramCtx->readBuff + SLOT_OFFSET(1) + N64DD,
-            sizeof(fileChooseCtx->n64ddFlags[0]));
-    MemCopy(&fileChooseCtx->n64ddFlags[2], sramCtx->readBuff + SLOT_OFFSET(2) + N64DD,
-            sizeof(fileChooseCtx->n64ddFlags[0]));
-
-    MemCopy(&fileChooseCtx->defense[0], sramCtx->readBuff + SLOT_OFFSET(0) + DEFENSE,
-            sizeof(fileChooseCtx->defense[0]));
-    MemCopy(&fileChooseCtx->defense[1], sramCtx->readBuff + SLOT_OFFSET(1) + DEFENSE,
-            sizeof(fileChooseCtx->defense[0]));
-    MemCopy(&fileChooseCtx->defense[2], sramCtx->readBuff + SLOT_OFFSET(2) + DEFENSE,
-            sizeof(fileChooseCtx->defense[0]));
-
-    MemCopy(&fileChooseCtx->health[0], sramCtx->readBuff + SLOT_OFFSET(0) + HEALTH, sizeof(fileChooseCtx->health[0]));
-    MemCopy(&fileChooseCtx->health[1], sramCtx->readBuff + SLOT_OFFSET(1) + HEALTH, sizeof(fileChooseCtx->health[0]));
-    MemCopy(&fileChooseCtx->health[2], sramCtx->readBuff + SLOT_OFFSET(2) + HEALTH, sizeof(fileChooseCtx->health[0]));
+    MemCpy(&fileChooseCtx->deaths[0], sramCtx->readBuff + SLOT_OFFSET(0) + DEATHS, sizeof(fileChooseCtx->deaths[0]));
+    MemCpy(&fileChooseCtx->deaths[1], sramCtx->readBuff + SLOT_OFFSET(1) + DEATHS, sizeof(fileChooseCtx->deaths[0]));
+    MemCpy(&fileChooseCtx->deaths[2], sramCtx->readBuff + SLOT_OFFSET(2) + DEATHS, sizeof(fileChooseCtx->deaths[0]));
+
+    MemCpy(&fileChooseCtx->fileNames[0], sramCtx->readBuff + SLOT_OFFSET(0) + NAME,
+           sizeof(fileChooseCtx->fileNames[0]));
+    MemCpy(&fileChooseCtx->fileNames[1], sramCtx->readBuff + SLOT_OFFSET(1) + NAME,
+           sizeof(fileChooseCtx->fileNames[0]));
+    MemCpy(&fileChooseCtx->fileNames[2], sramCtx->readBuff + SLOT_OFFSET(2) + NAME,
+           sizeof(fileChooseCtx->fileNames[0]));
+
+    MemCpy(&fileChooseCtx->healthCapacities[0], sramCtx->readBuff + SLOT_OFFSET(0) + HEALTH_CAP,
+           sizeof(fileChooseCtx->healthCapacities[0]));
+    MemCpy(&fileChooseCtx->healthCapacities[1], sramCtx->readBuff + SLOT_OFFSET(1) + HEALTH_CAP,
+           sizeof(fileChooseCtx->healthCapacities[0]));
+    MemCpy(&fileChooseCtx->healthCapacities[2], sramCtx->readBuff + SLOT_OFFSET(2) + HEALTH_CAP,
+           sizeof(fileChooseCtx->healthCapacities[0]));
+
+    MemCpy(&fileChooseCtx->questItems[0], sramCtx->readBuff + SLOT_OFFSET(0) + QUEST,
+           sizeof(fileChooseCtx->questItems[0]));
+    MemCpy(&fileChooseCtx->questItems[1], sramCtx->readBuff + SLOT_OFFSET(1) + QUEST,
+           sizeof(fileChooseCtx->questItems[0]));
+    MemCpy(&fileChooseCtx->questItems[2], sramCtx->readBuff + SLOT_OFFSET(2) + QUEST,
+           sizeof(fileChooseCtx->questItems[0]));
+
+    MemCpy(&fileChooseCtx->n64ddFlags[0], sramCtx->readBuff + SLOT_OFFSET(0) + N64DD,
+           sizeof(fileChooseCtx->n64ddFlags[0]));
+    MemCpy(&fileChooseCtx->n64ddFlags[1], sramCtx->readBuff + SLOT_OFFSET(1) + N64DD,
+           sizeof(fileChooseCtx->n64ddFlags[0]));
+    MemCpy(&fileChooseCtx->n64ddFlags[2], sramCtx->readBuff + SLOT_OFFSET(2) + N64DD,
+           sizeof(fileChooseCtx->n64ddFlags[0]));
+
+    MemCpy(&fileChooseCtx->defense[0], sramCtx->readBuff + SLOT_OFFSET(0) + DEFENSE, sizeof(fileChooseCtx->defense[0]));
+    MemCpy(&fileChooseCtx->defense[1], sramCtx->readBuff + SLOT_OFFSET(1) + DEFENSE, sizeof(fileChooseCtx->defense[0]));
+    MemCpy(&fileChooseCtx->defense[2], sramCtx->readBuff + SLOT_OFFSET(2) + DEFENSE, sizeof(fileChooseCtx->defense[0]));
+
+    MemCpy(&fileChooseCtx->health[0], sramCtx->readBuff + SLOT_OFFSET(0) + HEALTH, sizeof(fileChooseCtx->health[0]));
+    MemCpy(&fileChooseCtx->health[1], sramCtx->readBuff + SLOT_OFFSET(1) + HEALTH, sizeof(fileChooseCtx->health[0]));
+    MemCpy(&fileChooseCtx->health[2], sramCtx->readBuff + SLOT_OFFSET(2) + HEALTH, sizeof(fileChooseCtx->health[0]));
 
     osSyncPrintf("f_64dd=%d, %d, %d\n", fileChooseCtx->n64ddFlags[0], fileChooseCtx->n64ddFlags[1],
                  fileChooseCtx->n64ddFlags[2]);
@@ -741,11 +738,11 @@ void Sram_InitSave(FileChooseContext* fileChooseCtx, SramContext* sramCtx) {
 
     offset = gSramSlotOffsets[gSaveContext.fileNum];
     osSyncPrintf("I=%x no=%d\n", offset, gSaveContext.fileNum);
-    MemCopy(sramCtx->readBuff + offset, &gSaveContext, sizeof(Save));
+    MemCpy(sramCtx->readBuff + offset, &gSaveContext, sizeof(Save));
 
     offset = gSramSlotOffsets[gSaveContext.fileNum + 3];
     osSyncPrintf("I=%x no=%d\n", offset, gSaveContext.fileNum + 3);
-    MemCopy(sramCtx->readBuff + offset, &gSaveContext, sizeof(Save));
+    MemCpy(sramCtx->readBuff + offset, &gSaveContext, sizeof(Save));
 
     SsSram_ReadWrite(OS_K1_TO_PHYSICAL(0xA8000000), sramCtx->readBuff, SRAM_SIZE, OS_WRITE);
 
@@ -755,20 +752,20 @@ void Sram_InitSave(FileChooseContext* fileChooseCtx, SramContext* sramCtx) {
 
     j = gSramSlotOffsets[gSaveContext.fileNum];
 
-    MemCopy(&fileChooseCtx->deaths[gSaveContext.fileNum], sramCtx->readBuff + j + DEATHS,
-            sizeof(fileChooseCtx->deaths[0]));
-    MemCopy(&fileChooseCtx->fileNames[gSaveContext.fileNum], sramCtx->readBuff + j + NAME,
-            sizeof(fileChooseCtx->fileNames[0]));
-    MemCopy(&fileChooseCtx->healthCapacities[gSaveContext.fileNum], sramCtx->readBuff + j + HEALTH_CAP,
-            sizeof(fileChooseCtx->healthCapacities[0]));
-    MemCopy(&fileChooseCtx->questItems[gSaveContext.fileNum], sramCtx->readBuff + j + QUEST,
-            sizeof(fileChooseCtx->questItems[0]));
-    MemCopy(&fileChooseCtx->n64ddFlags[gSaveContext.fileNum], sramCtx->readBuff + j + N64DD,
-            sizeof(fileChooseCtx->n64ddFlags[0]));
-    MemCopy(&fileChooseCtx->defense[gSaveContext.fileNum], sramCtx->readBuff + j + DEFENSE,
-            sizeof(fileChooseCtx->defense[0]));
-    MemCopy(&fileChooseCtx->health[gSaveContext.fileNum], sramCtx->readBuff + j + HEALTH,
-            sizeof(fileChooseCtx->health[0]));
+    MemCpy(&fileChooseCtx->deaths[gSaveContext.fileNum], sramCtx->readBuff + j + DEATHS,
+           sizeof(fileChooseCtx->deaths[0]));
+    MemCpy(&fileChooseCtx->fileNames[gSaveContext.fileNum], sramCtx->readBuff + j + NAME,
+           sizeof(fileChooseCtx->fileNames[0]));
+    MemCpy(&fileChooseCtx->healthCapacities[gSaveContext.fileNum], sramCtx->readBuff + j + HEALTH_CAP,
+           sizeof(fileChooseCtx->healthCapacities[0]));
+    MemCpy(&fileChooseCtx->questItems[gSaveContext.fileNum], sramCtx->readBuff + j + QUEST,
+           sizeof(fileChooseCtx->questItems[0]));
+    MemCpy(&fileChooseCtx->n64ddFlags[gSaveContext.fileNum], sramCtx->readBuff + j + N64DD,
+           sizeof(fileChooseCtx->n64ddFlags[0]));
+    MemCpy(&fileChooseCtx->defense[gSaveContext.fileNum], sramCtx->readBuff + j + DEFENSE,
+           sizeof(fileChooseCtx->defense[0]));
+    MemCpy(&fileChooseCtx->health[gSaveContext.fileNum], sramCtx->readBuff + j + HEALTH,
+           sizeof(fileChooseCtx->health[0]));
 
     osSyncPrintf("f_64dd[%d]=%d\n", gSaveContext.fileNum, fileChooseCtx->n64ddFlags[gSaveContext.fileNum]);
     osSyncPrintf("heart_status[%d]=%d\n", gSaveContext.fileNum, fileChooseCtx->defense[gSaveContext.fileNum]);
@@ -781,14 +778,14 @@ void Sram_EraseSave(FileChooseContext* fileChooseCtx, SramContext* sramCtx) {
     Sram_InitNewSave();
 
     offset = gSramSlotOffsets[fileChooseCtx->selectedFileIndex];
-    MemCopy(sramCtx->readBuff + offset, &gSaveContext, sizeof(Save));
+    MemCpy(sramCtx->readBuff + offset, &gSaveContext, sizeof(Save));
     SsSram_ReadWrite(OS_K1_TO_PHYSICAL(0xA8000000) + offset, &gSaveContext, SLOT_SIZE, OS_WRITE);
 
-    MemCopy(&fileChooseCtx->n64ddFlags[fileChooseCtx->selectedFileIndex], sramCtx->readBuff + offset + N64DD,
-            sizeof(fileChooseCtx->n64ddFlags[0]));
+    MemCpy(&fileChooseCtx->n64ddFlags[fileChooseCtx->selectedFileIndex], sramCtx->readBuff + offset + N64DD,
+           sizeof(fileChooseCtx->n64ddFlags[0]));
 
     offset = gSramSlotOffsets[fileChooseCtx->selectedFileIndex + 3];
-    MemCopy(sramCtx->readBuff + offset, &gSaveContext, sizeof(Save));
+    MemCpy(sramCtx->readBuff + offset, &gSaveContext, sizeof(Save));
     SsSram_ReadWrite(OS_K1_TO_PHYSICAL(0xA8000000) + offset, &gSaveContext, SLOT_SIZE, OS_WRITE);
 
     osSyncPrintf("ＣＬＥＡＲ終了\n");
@@ -802,32 +799,32 @@ void Sram_CopySave(FileChooseContext* fileChooseCtx, SramContext* sramCtx) {
                  gSramSlotOffsets[fileChooseCtx->copyDestFileIndex]);
 
     offset = gSramSlotOffsets[fileChooseCtx->selectedFileIndex];
-    MemCopy(&gSaveContext, sramCtx->readBuff + offset, sizeof(Save));
+    MemCpy(&gSaveContext, sramCtx->readBuff + offset, sizeof(Save));
 
     offset = gSramSlotOffsets[fileChooseCtx->copyDestFileIndex];
-    MemCopy(sramCtx->readBuff + offset, &gSaveContext, sizeof(Save));
+    MemCpy(sramCtx->readBuff + offset, &gSaveContext, sizeof(Save));
 
     offset = gSramSlotOffsets[fileChooseCtx->copyDestFileIndex + 3];
-    MemCopy(sramCtx->readBuff + offset, &gSaveContext, sizeof(Save));
+    MemCpy(sramCtx->readBuff + offset, &gSaveContext, sizeof(Save));
 
     SsSram_ReadWrite(OS_K1_TO_PHYSICAL(0xA8000000), sramCtx->readBuff, SRAM_SIZE, OS_WRITE);
 
     offset = gSramSlotOffsets[fileChooseCtx->copyDestFileIndex];
 
-    MemCopy(&fileChooseCtx->deaths[fileChooseCtx->copyDestFileIndex], sramCtx->readBuff + offset + DEATHS,
-            sizeof(fileChooseCtx->deaths[0]));
-    MemCopy(&fileChooseCtx->fileNames[fileChooseCtx->copyDestFileIndex], sramCtx->readBuff + offset + NAME,
-            sizeof(fileChooseCtx->fileNames[0]));
-    MemCopy(&fileChooseCtx->healthCapacities[fileChooseCtx->copyDestFileIndex], sramCtx->readBuff + offset + HEALTH_CAP,
-            sizeof(fileChooseCtx->healthCapacities[0]));
-    MemCopy(&fileChooseCtx->questItems[fileChooseCtx->copyDestFileIndex], sramCtx->readBuff + offset + QUEST,
-            sizeof(fileChooseCtx->questItems[0]));
-    MemCopy(&fileChooseCtx->n64ddFlags[fileChooseCtx->copyDestFileIndex], sramCtx->readBuff + offset + N64DD,
-            sizeof(fileChooseCtx->n64ddFlags[0]));
-    MemCopy(&fileChooseCtx->defense[fileChooseCtx->copyDestFileIndex], sramCtx->readBuff + offset + DEFENSE,
-            sizeof(fileChooseCtx->defense[0]));
-    MemCopy(&fileChooseCtx->health[fileChooseCtx->copyDestFileIndex], (sramCtx->readBuff + offset) + HEALTH,
-            sizeof(fileChooseCtx->health[0]));
+    MemCpy(&fileChooseCtx->deaths[fileChooseCtx->copyDestFileIndex], sramCtx->readBuff + offset + DEATHS,
+           sizeof(fileChooseCtx->deaths[0]));
+    MemCpy(&fileChooseCtx->fileNames[fileChooseCtx->copyDestFileIndex], sramCtx->readBuff + offset + NAME,
+           sizeof(fileChooseCtx->fileNames[0]));
+    MemCpy(&fileChooseCtx->healthCapacities[fileChooseCtx->copyDestFileIndex], sramCtx->readBuff + offset + HEALTH_CAP,
+           sizeof(fileChooseCtx->healthCapacities[0]));
+    MemCpy(&fileChooseCtx->questItems[fileChooseCtx->copyDestFileIndex], sramCtx->readBuff + offset + QUEST,
+           sizeof(fileChooseCtx->questItems[0]));
+    MemCpy(&fileChooseCtx->n64ddFlags[fileChooseCtx->copyDestFileIndex], sramCtx->readBuff + offset + N64DD,
+           sizeof(fileChooseCtx->n64ddFlags[0]));
+    MemCpy(&fileChooseCtx->defense[fileChooseCtx->copyDestFileIndex], sramCtx->readBuff + offset + DEFENSE,
+           sizeof(fileChooseCtx->defense[0]));
+    MemCpy(&fileChooseCtx->health[fileChooseCtx->copyDestFileIndex], (sramCtx->readBuff + offset) + HEALTH,
+           sizeof(fileChooseCtx->health[0]));
 
     osSyncPrintf("f_64dd[%d]=%d\n", gSaveContext.fileNum, fileChooseCtx->n64ddFlags[gSaveContext.fileNum]);
     osSyncPrintf("heart_status[%d]=%d\n", gSaveContext.fileNum, fileChooseCtx->defense[gSaveContext.fileNum]);
@@ -851,7 +848,7 @@ void Sram_InitSram(GameState* gameState, SramContext* sramCtx) {
         if (sZeldaMagic[i + SRAM_HEADER_MAGIC] != sramCtx->readBuff[i + SRAM_HEADER_MAGIC]) {
             osSyncPrintf("ＳＲＡＭ破壊！！！！！！\n"); // "SRAM destruction! ! ! ! ! !"
             gSaveContext.language = sramCtx->readBuff[SRAM_HEADER_LANGUAGE];
-            MemCopy(sramCtx->readBuff, sZeldaMagic, sizeof(sZeldaMagic));
+            MemCpy(sramCtx->readBuff, sZeldaMagic, sizeof(sZeldaMagic));
             sramCtx->readBuff[SRAM_HEADER_LANGUAGE] = gSaveContext.language;
             Sram_WriteSramHeader(sramCtx);
         }
diff --git a/src/code/z_view.c b/src/code/z_view.c
index 9ed5fad57..0a847ef49 100644
--- a/src/code/z_view.c
+++ b/src/code/z_view.c
@@ -24,7 +24,7 @@ View* View_New(GraphicsContext* gfxCtx) {
     View* view = SystemArena_MallocDebug(sizeof(View), "../z_view.c", 285);
 
     if (view != NULL) {
-        func_80106860(view, 0, sizeof(View)); // memset
+        __osMemset(view, 0, sizeof(View));
         View_Init(view, gfxCtx);
     }
 
diff --git a/src/libultra/libc/string.c b/src/libultra/libc/string.c
index bf059094f..37091ab83 100644
--- a/src/libultra/libc/string.c
+++ b/src/libultra/libc/string.c
@@ -21,7 +21,7 @@ u32 strlen(const char* str) {
     return ptr - str;
 }
 
-void* memcpy(void* dst, const void* src, u32 size) {
+void* memcpy(void* dst, const void* src, size_t size) {
     u8* _dst = dst;
     const u8* _src = src;
 
diff --git a/src/overlays/actors/ovl_Bg_Jya_Cobra/z_bg_jya_cobra.c b/src/overlays/actors/ovl_Bg_Jya_Cobra/z_bg_jya_cobra.c
index 2ea13e616..ef46bb261 100644
--- a/src/overlays/actors/ovl_Bg_Jya_Cobra/z_bg_jya_cobra.c
+++ b/src/overlays/actors/ovl_Bg_Jya_Cobra/z_bg_jya_cobra.c
@@ -264,7 +264,7 @@ void BgJyaCobra_UpdateShadowFromSide(BgJyaCobra* this) {
     Vec3f spD4;
     Vec3f spC8;
     Vec3f spBC;
-    u8* temp_s2;
+    u8* shadowTex;
     s32 temp_x;
     s32 temp_z;
     s32 x;
@@ -275,8 +275,8 @@ void BgJyaCobra_UpdateShadowFromSide(BgJyaCobra* this) {
     s32 l;
     s16 rotY;
 
-    temp_s2 = ALIGN16((s32)(&this->shadowTexture));
-    Lib_MemSet(temp_s2, 0x1000, 0);
+    shadowTex = COBRA_SHADOW_TEX_PTR(this);
+    Lib_MemSet(shadowTex, COBRA_SHADOW_TEX_SIZE, 0);
 
     Matrix_RotateX((M_PI / 4), MTXMODE_NEW);
     rotY = !(this->dyna.actor.params & 3) ? (this->dyna.actor.shape.rot.y + 0x4000)
@@ -303,7 +303,7 @@ void BgJyaCobra_UpdateShadowFromSide(BgJyaCobra* this) {
                     for (l = 0; l < 11; l++) {
                         temp_x = x - 5 + l;
                         if (!(temp_x & ~0x3F)) {
-                            temp_s2[temp_z + temp_x] |= D_8089731C[k][l];
+                            shadowTex[temp_z + temp_x] |= D_8089731C[k][l];
                         }
                         if (1) {}
                     }
@@ -331,7 +331,7 @@ void BgJyaCobra_UpdateShadowFromSide(BgJyaCobra* this) {
                     for (l = 0; l < 3; l++) {
                         temp_x = x - 1 + l;
                         if (!(temp_x & ~0x3F)) {
-                            temp_s2[temp_z + temp_x] |= D_80897398[k][l];
+                            shadowTex[temp_z + temp_x] |= D_80897398[k][l];
                         }
                     }
                 }
@@ -340,13 +340,13 @@ void BgJyaCobra_UpdateShadowFromSide(BgJyaCobra* this) {
     }
 
     for (i = 0; i < 0x40; i++) {
-        temp_s2[0 * 0x40 + i] = 0;
-        temp_s2[0x3F * 0x40 + i] = 0;
+        shadowTex[0 * 0x40 + i] = 0;
+        shadowTex[0x3F * 0x40 + i] = 0;
     }
 
     for (j = 1; j < 0x3F; j++) {
-        temp_s2[j * 0x40 + 0] = 0;
-        temp_s2[j * 0x40 + 0x3F] = 0;
+        shadowTex[j * 0x40 + 0] = 0;
+        shadowTex[j * 0x40 + 0x3F] = 0;
     }
     if (D_80897398[0][0]) {}
 }
@@ -360,15 +360,15 @@ void BgJyaCobra_UpdateShadowFromTop(BgJyaCobra* this) {
     s32 j;
     s32 i_copy;
     s32 counter;
-    u8* temp_s0;
+    u8* shadowTex;
     u8* sp40;
 
     for (i = 0; i < 0x40; i++) {
         sp58[i] = SQ(i - 31.5f);
     }
 
-    sp40 = temp_s0 = (u8*)ALIGN16((u32)(&this->shadowTexture));
-    Lib_MemSet(temp_s0, 0x1000, 0);
+    sp40 = shadowTex = COBRA_SHADOW_TEX_PTR(this);
+    Lib_MemSet(shadowTex, COBRA_SHADOW_TEX_SIZE, 0);
 
     for (i = 0; i != 0x40; i++) {
         f32 temp_f12 = sp58[i];
@@ -385,12 +385,12 @@ void BgJyaCobra_UpdateShadowFromTop(BgJyaCobra* this) {
     for (i_copy = 0x780, counter = 0; counter < 4; counter++, i_copy += 0x40) {
         i = i_copy;
         for (j = 4; j < 0x3C; j++) {
-            if (temp_s0[i_copy + j] < D_80897518[counter]) {
-                temp_s0[i_copy + j] = D_80897518[counter];
+            if (shadowTex[i_copy + j] < D_80897518[counter]) {
+                shadowTex[i_copy + j] = D_80897518[counter];
             }
         }
-        temp_s0[i + 0x3C] = 0x20;
-        temp_s0[i + 0x3] = 0x20;
+        shadowTex[i + 0x3C] = 0x20;
+        shadowTex[i + 0x3] = 0x20;
     }
 }
 
@@ -419,7 +419,7 @@ void BgJyaCobra_Init(Actor* thisx, GlobalContext* globalCtx) {
 
     // "(jya cobra)"
     osSyncPrintf("(jya コブラ)(arg_data 0x%04x)(act %x)(txt %x)(txt16 %x)\n", this->dyna.actor.params, this,
-                 &this->shadowTexture, ALIGN16((s32)(&this->shadowTexture)));
+                 &this->shadowTextureBuffer, COBRA_SHADOW_TEX_PTR(this));
 }
 
 void BgJyaCobra_Destroy(Actor* thisx, GlobalContext* globalCtx) {
@@ -590,9 +590,9 @@ void BgJyaCobra_DrawShadow(BgJyaCobra* this, GlobalContext* globalCtx) {
     gSPMatrix(POLY_XLU_DISP++, Matrix_NewMtx(globalCtx->state.gfxCtx, "../z_bg_jya_cobra.c", 994),
               G_MTX_NOPUSH | G_MTX_LOAD | G_MTX_MODELVIEW);
 
-    gDPLoadTextureBlock(POLY_XLU_DISP++, ALIGN16((s32)(&this->shadowTexture)), G_IM_FMT_I, G_IM_SIZ_8b, 0x40, 0x40, 0,
-                        G_TX_NOMIRROR | G_TX_CLAMP, G_TX_NOMIRROR | G_TX_CLAMP, G_TX_NOMASK, G_TX_NOMASK, G_TX_NOLOD,
-                        G_TX_NOLOD);
+    gDPLoadTextureBlock(POLY_XLU_DISP++, COBRA_SHADOW_TEX_PTR(this), G_IM_FMT_I, G_IM_SIZ_8b, COBRA_SHADOW_TEX_WIDTH,
+                        COBRA_SHADOW_TEX_HEIGHT, 0, G_TX_NOMIRROR | G_TX_CLAMP, G_TX_NOMIRROR | G_TX_CLAMP, G_TX_NOMASK,
+                        G_TX_NOMASK, G_TX_NOLOD, G_TX_NOLOD);
 
     gSPDisplayList(POLY_XLU_DISP++, sShadowDL);
 
diff --git a/src/overlays/actors/ovl_Bg_Jya_Cobra/z_bg_jya_cobra.h b/src/overlays/actors/ovl_Bg_Jya_Cobra/z_bg_jya_cobra.h
index f9ad1e6c5..b7006632f 100644
--- a/src/overlays/actors/ovl_Bg_Jya_Cobra/z_bg_jya_cobra.h
+++ b/src/overlays/actors/ovl_Bg_Jya_Cobra/z_bg_jya_cobra.h
@@ -8,6 +8,11 @@ struct BgJyaCobra;
 
 typedef void (*BgJyaCobraActionFunc)(struct BgJyaCobra*, GlobalContext*);
 
+#define COBRA_SHADOW_TEX_WIDTH 64
+#define COBRA_SHADOW_TEX_HEIGHT 64
+#define COBRA_SHADOW_TEX_SIZE (COBRA_SHADOW_TEX_WIDTH * COBRA_SHADOW_TEX_HEIGHT * G_IM_SIZ_8b_BYTES)
+#define COBRA_SHADOW_TEX_PTR(this) (u8*)ALIGN16((u32)(&this->shadowTextureBuffer))
+
 typedef struct BgJyaCobra {
     /* 0x0000 */ DynaPolyActor dyna;
     /* 0x0164 */ BgJyaCobraActionFunc actionFunc;
@@ -21,7 +26,7 @@ typedef struct BgJyaCobra {
     /* 0x0180 */ Vec3f unk_180;
     /* 0x018C */ f32 unk_18C;
     /* 0x0190 */ f32 unk_190;
-    /* 0x0194 */ u8 shadowTexture[0x1010];
+    /* 0x0194 */ u8 shadowTextureBuffer[COBRA_SHADOW_TEX_SIZE / sizeof(u8) + 0xF]; // Extra space to allow aligning actual texture to 0x10
 } BgJyaCobra; // size = 0x11A4
 
 #endif
diff --git a/src/overlays/gamestates/ovl_file_choose/z_file_choose.c b/src/overlays/gamestates/ovl_file_choose/z_file_choose.c
index 12501d6c9..b7b3706cf 100644
--- a/src/overlays/gamestates/ovl_file_choose/z_file_choose.c
+++ b/src/overlays/gamestates/ovl_file_choose/z_file_choose.c
@@ -193,7 +193,7 @@ void FileChoose_UpdateMainMenu(GameState* thisx) {
                 this->newFileNameCharCount = 0;
                 this->nameEntryBoxPosX = 120;
                 this->nameEntryBoxAlpha = 0;
-                MemCopy(&this->fileNames[this->buttonIndex][0], &emptyName, 8);
+                MemCpy(&this->fileNames[this->buttonIndex][0], &emptyName, sizeof(emptyName));
             } else if (this->n64ddFlags[this->buttonIndex] == this->n64ddFlag) {
                 Audio_PlaySoundGeneral(NA_SE_SY_FSEL_DECIDE_L, &gSfxDefaultPos, 4, &gSfxDefaultFreqAndVolScale,
                                        &gSfxDefaultFreqAndVolScale, &gSfxDefaultReverb);