sys_initial_check OK, documented, error message files debinarised (#437)

* OK

* Symbols and other documentation

* Remove externs

* spec

* More documentation, decompile the texture files,
some uintptr_t and size_t

* Top-of-file comment

* Move symbols back into right order

* Use some defines

* Missed an osTvType and a size_t

* Add missing header to os.h

* Use segment symbol macros

* Remove duplicate header

* Address review suggestions

assets/xml/misc/locerrmsg.xml

@@ -0,0 +1,5 @@
+<Root>
+	<File Name="locerrmsg" Segment="1">
+		<Texture Name="gNotDesignedForSystemErrorTex" OutName="not_designed_for_system_error" Format="i4" Width="208" Height="16" Offset="0x0"/>
+	</File>
+</Root>

assets/xml/misc/memerrmsg.xml

@@ -0,0 +1,6 @@
+<Root>
+	<File Name="memerrmsg" Segment="1">
+		<Texture Name="gExpansionPakNotInstalledErrorTex" OutName="expansion_pak_not_installed_error" Format="i4" Width="128" Height="37" Offset="0x0"/>
+		<Texture Name="gSeeInstructionBookletErrorTex" OutName="see_instruction_booklet_error" Format="i4" Width="128" Height="37" Offset="0x940"/>
+	</File>
+</Root>

include/color.h

@@ -3,6 +3,9 @@
 
 #include "PR/ultratypes.h"
 
+// For checking the alpha bit in an RGBA16 pixel
+#define RGBA16_PIXEL_OPAQUE 1
+
 typedef struct {
     /* 0x0 */ u8 r;
     /* 0x1 */ u8 g;

include/functions.h

@@ -15,9 +15,9 @@ s32 DmaMgr_FindDmaIndex(u32 vromAddr);
 const char* func_800809F4(u32 param_1);
 void DmaMgr_ProcessMsg(DmaRequest* req);
 void DmaMgr_ThreadEntry(void* arg);
-s32 DmaMgr_SendRequestImpl(DmaRequest* request, void* vramStart, u32 vromStart, size_t size, UNK_TYPE4 unused,
+s32 DmaMgr_SendRequestImpl(DmaRequest* request, void* vramStart, uintptr_t vromStart, size_t size, UNK_TYPE4 unused,
                            OSMesgQueue* callback, void* callbackMesg);
-s32 DmaMgr_SendRequest0(void* vramStart, u32 vromStart, size_t size);
+s32 DmaMgr_SendRequest0(void* vramStart, uintptr_t vromStart, size_t size);
 void DmaMgr_Start(void);
 void DmaMgr_Stop(void);
 void* Yaz0_FirstDMA(void);
@@ -356,8 +356,8 @@ const char* strchr(const char* __s, s32 __c);
 size_t strlen(const char* __s);
 void* memcpy(void* __dest, const void* __src, size_t __n);
 void osCreateMesgQueue(OSMesgQueue* mq, OSMesg* msq, s32 count);
-void osInvalICache(void* vaddr, s32 nbytes);
+void osInvalICache(void* vaddr, size_t nbytes);
-void osInvalDCache(void* vaddr, s32 nbytes);
+void osInvalDCache(void* vaddr, size_t nbytes);
 void __osTimerServicesInit(void);
 void __osTimerInterrupt(void);
 void __osSetTimerIntr(OSTime tim);
@@ -3257,10 +3257,10 @@ s32 func_80178A94(s32 param_1, s32 param_2);
 // void func_80178DAC(void);
 // void func_80178E3C(void);
 // void func_80178E7C(void);
-void Check_WriteRGBA16Pixel(u16* buffer, u32 x, u32 y, u16 value);
+// void Check_WriteRGBA16Pixel(u16* buffer, u32 x, u32 y, u32 value);
-void Check_WriteI4Pixel(u16* buffer, u32 x, u32 y, u32 value);
+// void Check_WriteI4Pixel(u16* buffer, u32 x, u32 y, u32 value);
-void Check_DrawI4Texture(u16* buffer, u32 x, u32 y, u32 width, u32 height, u8* texture);
+// void Check_DrawI4Texture(u16* buffer, u32 x, u32 y, u32 width, u32 height, u8* texture);
-void Check_ClearRGBA16(s16* buffer);
+// void Check_ClearRGBA16(u16* buffer);
 // void Check_DrawExpansionPakErrorMessage(void);
 // void Check_DrawRegionLockErrorMessage(void);
 void Check_ExpansionPak(void);

include/os.h

@@ -1,6 +1,7 @@
 #ifndef _OS_H_
 #define _OS_H_
 
+#include "libc/stdint.h"
 #include "libc/stdlib.h"
 #include "ultra64/thread.h"
 #include "ultra64/message.h"
@@ -84,7 +85,7 @@ typedef struct {
 typedef struct {
     /* 0x00 */ OSIoMesgHdr hdr;
     /* 0x08 */ void* dramAddr;
-    /* 0x0C */ u32 devAddr;
+    /* 0x0C */ uintptr_t devAddr;
     /* 0x10 */ size_t size;
     /* 0x14 */ OSPiHandle* piHandle;
 } OSIoMesg; // size = 0x88

include/segment_symbols.h

@@ -1161,7 +1161,9 @@ DECLARE_ROM_SEGMENT(scene_texture_07)
 DECLARE_ROM_SEGMENT(scene_texture_08)
 DECLARE_ROM_SEGMENT(nintendo_rogo_static)
 DECLARE_ROM_SEGMENT(title_static)
+DECLARE_SEGMENT(memerrmsg)
 DECLARE_ROM_SEGMENT(memerrmsg)
+DECLARE_SEGMENT(locerrmsg)
 DECLARE_ROM_SEGMENT(locerrmsg)
 DECLARE_ROM_SEGMENT(parameter_static)
 DECLARE_ROM_SEGMENT(week_static)

include/ultra64/vi.h

@@ -5,14 +5,14 @@
 #include "ultra64/message.h"
 
 /* Special Features */
-#define OS_VI_GAMMA_ON          0x0001
+#define OS_VI_GAMMA_ON          (1 << 0)
-#define OS_VI_GAMMA_OFF         0x0002
+#define OS_VI_GAMMA_OFF         (1 << 1)
-#define OS_VI_GAMMA_DITHER_ON   0x0004
+#define OS_VI_GAMMA_DITHER_ON   (1 << 2)
-#define OS_VI_GAMMA_DITHER_OFF  0x0008
+#define OS_VI_GAMMA_DITHER_OFF  (1 << 3)
-#define OS_VI_DIVOT_ON          0x0010
+#define OS_VI_DIVOT_ON          (1 << 4)
-#define OS_VI_DIVOT_OFF         0x0020
+#define OS_VI_DIVOT_OFF         (1 << 5)
-#define OS_VI_DITHER_FILTER_ON  0x0040
+#define OS_VI_DITHER_FILTER_ON  (1 << 6)
-#define OS_VI_DITHER_FILTER_OFF 0x0080
+#define OS_VI_DITHER_FILTER_OFF (1 << 7)
 
 #define OS_VI_GAMMA         0x08
 #define OS_VI_GAMMA_DITHER  0x04

include/variables.h

@@ -12,7 +12,7 @@ extern u32 osRomBase;
 extern u32 osResetType;
 extern u32 osCicId;
 extern u32 osVersion;
-extern u32 osMemSize;
+extern size_t osMemSize;
 extern s32 osAppNmiBuffer[0x10];
 extern u16 gFramebuffer1[SCREEN_HEIGHT][SCREEN_WIDTH]; // at 0x80000500
 extern u8 D_80025D00[];

include/z64.h

@@ -513,6 +513,13 @@ typedef union {
     F3DVertexNormal normal;
 } F3DVertex; // size = 0x10
 
+// End of RDRAM without the Expansion Pak installed
+#define NORMAL_RDRAM_END 0x80400000
+// End of RDRAM with the Expansion Pak installed
+#define EXPANDED_RDRAM_END 0x80800000
+// Address at the end of normal RDRAM after which is room for a screen buffer
+#define FAULT_FB_ADDRESS (NORMAL_RDRAM_END - sizeof(u16[SCREEN_HEIGHT][SCREEN_WIDTH]))
+
 typedef struct {
     /* 0x00 */ u16* fb;
     /* 0x04 */ u16 w;

spec

@@ -8860,14 +8860,16 @@ beginseg
     name "memerrmsg"
     compress
     romalign 0x1000
-    include "build/baserom/memerrmsg.o"
+    include "build/assets/misc/memerrmsg/memerrmsg.o"
+    number 1
 endseg
 
 beginseg
     name "locerrmsg"
     compress
     romalign 0x1000
-    include "build/baserom/locerrmsg.o"
+    include "build/assets/misc/locerrmsg/locerrmsg.o"
+    number 1
 endseg
 
 beginseg

src/boot_O2_g3/CIC6105.c

@@ -1,6 +1,5 @@
 #include "prevent_bss_reordering.h"
 #include "global.h"
-#include "prevent_bss_reordering.h"
 
 UNK_TYPE4 D_8009BE30;
 UNK_TYPE4 D_8009BE34;

src/boot_O2_g3/fault.c

@@ -714,7 +714,7 @@ void Fault_CommitFB() {
     osViSetYScale(1.0f);
     osViSetMode(&osViModeNtscLan1);
     osViSetSpecialFeatures(0x42); // gama_disable|dither_fliter_enable_aa_mode3_disable
-    osViBlack(0);
+    osViBlack(false);
 
     if (sFaultContext->fb) {
         fb = sFaultContext->fb;

src/boot_O2_g3/fault_drawer.c

@@ -5,7 +5,7 @@ extern const u32 sFaultDrawerFont[];
 
 FaultDrawer* sFaultDrawContext = &sFaultDrawerStruct;
 FaultDrawer sFaultDrawerDefault = {
-    (u16*)0x803DA800,                   // fb - TODO map out buffers in this region and avoid hard-coded pointer
+    (u16*)FAULT_FB_ADDRESS,             // fb
     SCREEN_WIDTH,                       // w
     SCREEN_HEIGHT,                      // h
     16,                                 // yStart

src/boot_O2_g3/idle.c

@@ -19,11 +19,11 @@ OSMesgQueue gPiMgrCmdQ;
 
 void Idle_ClearMemory(void* begin, void* end) {
     if (begin < end) {
-        bzero(begin, (u32)end - (u32)begin);
+        bzero(begin, (uintptr_t)end - (uintptr_t)begin);
     }
 }
 
-void Idle_InitFramebuffer(u32* ptr, u32 numBytes, u32 value) {
+void Idle_InitFramebuffer(u32* ptr, size_t numBytes, u32 value) {
     s32 temp = sizeof(u32);
 
     while (numBytes) {
@@ -36,7 +36,7 @@ void Idle_InitScreen(void) {
     Idle_InitFramebuffer((u32*)gFramebuffer1, 0x25800, 0x00010001);
     ViConfig_UpdateVi(0);
     osViSwapBuffer(gFramebuffer1);
-    osViBlack(0);
+    osViBlack(false);
 }
 
 void Idle_InitMemory(void) {
@@ -52,7 +52,7 @@ void Idle_InitCodeAndMemory(void) {
     DmaRequest dmaReq;
     OSMesgQueue queue;
     OSMesg mesg;
-    u32 oldSize;
+    size_t oldSize;
 
     osCreateMesgQueue(&queue, &mesg, 1);
 
@@ -71,7 +71,7 @@ void Idle_InitCodeAndMemory(void) {
 }
 
 void Main_ThreadEntry(void* arg) {
-    StackCheck_Init(&sIrqMgrStackInfo, sIrqMgrStack, sIrqMgrStack + sizeof(sIrqMgrStack), 0, 256, "irqmgr");
+    StackCheck_Init(&sIrqMgrStackInfo, sIrqMgrStack, sIrqMgrStack + sizeof(sIrqMgrStack), 0, 0x100, "irqmgr");
     IrqMgr_Init(&gIrqMgr, &sIrqMgrStackInfo, Z_PRIORITY_IRQMGR, 1);
     DmaMgr_Start();
     Idle_InitCodeAndMemory();
@@ -87,15 +87,15 @@ void Idle_InitVideo(void) {
     gViConfigYScale = 1.0;
 
     switch (osTvType) {
-        case 1:
+        case OS_TV_NTSC:
             D_8009B290 = 2;
             gViConfigMode = osViModeNtscLan1;
             break;
-        case 2:
+        case OS_TV_MPAL:
             D_8009B290 = 30;
             gViConfigMode = osViModeMpalLan1;
             break;
-        case 0:
+        case OS_TV_PAL:
             D_8009B290 = 44;
             gViConfigMode = osViModeFpalLan1;
             gViConfigYScale = 0.833f;
@@ -108,7 +108,7 @@ void Idle_InitVideo(void) {
 void Idle_ThreadEntry(void* arg) {
     Idle_InitVideo();
     osCreatePiManager(150, &gPiMgrCmdQ, sPiMgrCmdBuff, ARRAY_COUNT(sPiMgrCmdBuff));
-    StackCheck_Init(&sMainStackInfo, sMainStack, sMainStack + sizeof(sMainStack), 0, 1024, "main");
+    StackCheck_Init(&sMainStackInfo, sMainStack, sMainStack + sizeof(sMainStack), 0, 0x400, "main");
     osCreateThread(&gMainThread, Z_THREAD_ID_MAIN, Main_ThreadEntry, arg, sMainStack + sizeof(sMainStack),
                    Z_PRIORITY_MAIN);
     osStartThread(&gMainThread);

src/boot_O2_g3/viconfig.c

@@ -3,13 +3,13 @@
 void ViConfig_UpdateVi(u32 mode) {
     if (mode != 0) {
         switch (osTvType) {
-            case 2:
+            case OS_TV_MPAL:
                 osViSetMode(&osViModeMpalLan1);
                 break;
-            case 0:
+            case OS_TV_PAL:
                 osViSetMode(&osViModePalLan1);
                 break;
-            case 1:
+            case OS_TV_NTSC:
             default:
                 osViSetMode(&osViModeNtscLan1);
                 break;
@@ -47,8 +47,8 @@ void ViConfig_UpdateVi(u32 mode) {
 
 void ViConfig_UpdateBlack(void) {
     if (gViConfigUseDefault != 0) {
-        osViBlack(1);
+        osViBlack(true);
     } else {
-        osViBlack(0);
+        osViBlack(false);
     }
 }

src/boot_O2_g3/z_std_dma.c

@@ -9,12 +9,12 @@ OSMesg sDmaMgrMsgs[32];
 OSThread sDmaMgrThread;
 u8 sDmaMgrStack[0x500];
 
-s32 DmaMgr_DMARomToRam(u32 rom, void* ram, size_t size) {
+s32 DmaMgr_DMARomToRam(uintptr_t rom, void* ram, size_t size) {
     OSIoMesg ioMsg;
     OSMesgQueue queue;
     OSMesg msg[1];
     s32 ret;
-    u32 buffSize = sDmaMgrDmaBuffSize;
+    size_t buffSize = sDmaMgrDmaBuffSize;
 
     osInvalDCache(ram, size);
     osCreateMesgQueue(&queue, msg, ARRAY_COUNT(msg));
@@ -23,7 +23,7 @@ s32 DmaMgr_DMARomToRam(u32 rom, void* ram, size_t size) {
         while (buffSize < size) {
             ioMsg.hdr.pri = 0;
             ioMsg.hdr.retQueue = &queue;
-            ioMsg.devAddr = (u32)rom;
+            ioMsg.devAddr = rom;
             ioMsg.dramAddr = ram;
             ioMsg.size = buffSize;
             ret = osEPiStartDma(gCartHandle, &ioMsg, 0);
@@ -39,9 +39,9 @@ s32 DmaMgr_DMARomToRam(u32 rom, void* ram, size_t size) {
     }
     ioMsg.hdr.pri = 0;
     ioMsg.hdr.retQueue = &queue;
-    ioMsg.devAddr = (u32)rom;
+    ioMsg.devAddr = rom;
     ioMsg.dramAddr = ram;
-    ioMsg.size = (u32)size;
+    ioMsg.size = size;
     ret = osEPiStartDma(gCartHandle, &ioMsg, 0);
     if (ret) {
         goto END;
@@ -109,11 +109,11 @@ const char* func_800809F4(u32 a0) {
 }
 
 void DmaMgr_ProcessMsg(DmaRequest* req) {
-    u32 vrom;
+    uintptr_t vrom;
     void* ram;
     size_t size;
-    u32 romStart;
+    uintptr_t romStart;
-    u32 romSize;
+    size_t romSize;
     DmaEntry* dmaEntry;
     s32 index;
 
@@ -172,7 +172,7 @@ void DmaMgr_ThreadEntry(void* a0) {
     }
 }
 
-s32 DmaMgr_SendRequestImpl(DmaRequest* request, void* vramStart, u32 vromStart, size_t size, UNK_TYPE4 unused,
+s32 DmaMgr_SendRequestImpl(DmaRequest* request, void* vramStart, uintptr_t vromStart, size_t size, UNK_TYPE4 unused,
                            OSMesgQueue* queue, OSMesg msg) {
     if (gIrqMgrResetStatus >= 2) {
         return -2;
@@ -190,7 +190,7 @@ s32 DmaMgr_SendRequestImpl(DmaRequest* request, void* vramStart, u32 vromStart,
     return 0;
 }
 
-s32 DmaMgr_SendRequest0(void* vramStart, u32 vromStart, size_t size) {
+s32 DmaMgr_SendRequest0(void* vramStart, uintptr_t vromStart, size_t size) {
     DmaRequest req;
     OSMesgQueue queue;
     OSMesg msg[1];

src/code/sys_initial_check.c

@@ -1,17 +1,116 @@
+/**
+ * File: sys_initial_check.c
+ * Description: Functions for checking for the presence of the Expansion Pak and the correct TV type (PAL/NTSC/MPAL),
+ * and functions for printing error messages directly to screen if not found or incorrect.
+ *
+ * These checks are some of the first functions run in Main, before even setting up the system heap, and any image files
+ * are DMA'd directly to fixed RAM addresses.
+ */
 #include "global.h"
+#include "misc/locerrmsg/locerrmsg.h"
+#include "misc/memerrmsg/memerrmsg.h"
 
-#pragma GLOBAL_ASM("asm/non_matchings/code/sys_initial_check/Check_WriteRGBA16Pixel.s")
+#define SIZEOF_LOCERRMSG (sizeof(gNotDesignedForSystemErrorTex))
+#define SIZEOF_MEMERRMSG (sizeof(gExpansionPakNotInstalledErrorTex) + sizeof(gSeeInstructionBookletErrorTex))
 
-#pragma GLOBAL_ASM("asm/non_matchings/code/sys_initial_check/Check_WriteI4Pixel.s")
+// Address with enough room after to load either of the error message image files before the fault screen buffer at the
+// end of RDRAM
+#define CHECK_ERRMSG_STATIC_SEGMENT (u8*)(FAULT_FB_ADDRESS - MAX(SIZEOF_LOCERRMSG, SIZEOF_MEMERRMSG))
 
-#pragma GLOBAL_ASM("asm/non_matchings/code/sys_initial_check/Check_DrawI4Texture.s")
+void Check_WriteRGBA16Pixel(u16* buffer, u32 x, u32 y, u32 value) {
+    if (value & RGBA16_PIXEL_OPAQUE) {
+        (&buffer[x])[y * SCREEN_WIDTH] = value;
+    }
+}
 
-#pragma GLOBAL_ASM("asm/non_matchings/code/sys_initial_check/Check_ClearRGBA16.s")
+void Check_WriteI4Pixel(u16* buffer, u32 x, u32 y, u32 value) {
+    Check_WriteRGBA16Pixel(buffer, x, y, value * GPACK_RGBA5551(16, 16, 16, 0) + GPACK_RGBA5551(12, 12, 12, 1));
+}
 
-#pragma GLOBAL_ASM("asm/non_matchings/code/sys_initial_check/Check_DrawExpansionPakErrorMessage.s")
+/**
+ * x and y are the coordinates of the bottom-left corner.
+ */
+void Check_DrawI4Texture(u16* buffer, s32 x, s32 y, s32 width, s32 height, u8* texture) {
+    s32 v;
+    s32 u;
+    u8 pixelPair;
+    u8* pixelPairPtr = texture;
 
-#pragma GLOBAL_ASM("asm/non_matchings/code/sys_initial_check/Check_DrawRegionLockErrorMessage.s")
+    // I4 textures are bitpacked 2 pixels per byte, so this writes a pair of pixels in each iteration using bitmasking.
+    for (v = 0; v < height; v++) {
+        for (u = 0; u < width; u += 2, pixelPairPtr++) {
+            pixelPair = *pixelPairPtr;
+            Check_WriteI4Pixel(buffer, x + u, y + v, pixelPair >> 4);
+            pixelPair = *pixelPairPtr;
+            Check_WriteI4Pixel(buffer, x + u + 1, y + v, pixelPair & 0xF);
+        }
+    }
+}
 
-#pragma GLOBAL_ASM("asm/non_matchings/code/sys_initial_check/Check_ExpansionPak.s")
+void Check_ClearRGBA16(u16* buffer) {
+    u32 x;
+    u32 y;
 
-#pragma GLOBAL_ASM("asm/non_matchings/code/sys_initial_check/Check_RegionIsSupported.s")
+    for (y = 0; y < SCREEN_HEIGHT; y++) {
+        for (x = 0; x < SCREEN_WIDTH; x++) {
+            Check_WriteRGBA16Pixel(buffer, x, y, 1);
+        }
+    }
+}
+
+/**
+ * Draw error message textures directly to a screen buffer at the end of normal RDRAM
+ */
+void Check_DrawExpansionPakErrorMessage(void) {
+    DmaMgr_SendRequest0(CHECK_ERRMSG_STATIC_SEGMENT, SEGMENT_ROM_START(memerrmsg), SEGMENT_SIZE(memerrmsg));
+    Check_ClearRGBA16((u16*)FAULT_FB_ADDRESS);
+    Check_DrawI4Texture((u16*)FAULT_FB_ADDRESS, 96, 71, 128, 37, CHECK_ERRMSG_STATIC_SEGMENT);
+    Check_DrawI4Texture((u16*)FAULT_FB_ADDRESS, 96, 127, 128, 37,
+                        CHECK_ERRMSG_STATIC_SEGMENT + sizeof(gExpansionPakNotInstalledErrorTex));
+    osWritebackDCacheAll();
+    osViSwapBuffer((u16*)FAULT_FB_ADDRESS);
+    osViBlack(false);
+}
+
+/**
+ * Draw error message texture directly to a screen buffer at the end of normal RDRAM
+ */
+void Check_DrawRegionLockErrorMessage(void) {
+    DmaMgr_SendRequest0(CHECK_ERRMSG_STATIC_SEGMENT, SEGMENT_ROM_START(locerrmsg), SEGMENT_SIZE(locerrmsg));
+    Check_ClearRGBA16((u16*)FAULT_FB_ADDRESS);
+    Check_DrawI4Texture((u16*)FAULT_FB_ADDRESS, 56, 112, 208, 16, CHECK_ERRMSG_STATIC_SEGMENT);
+    osWritebackDCacheAll();
+    osViSwapBuffer((u16*)FAULT_FB_ADDRESS);
+    osViBlack(false);
+}
+
+/**
+ * If Expansion pak is not installed, display error message until console is turned off
+ */
+void Check_ExpansionPak(void) {
+    // Expansion pak installed
+    if (osMemSize >= 0x800000) {
+        return;
+    }
+
+    Check_DrawExpansionPakErrorMessage();
+    osDestroyThread(NULL);
+    while (true) {}
+}
+
+/**
+ * If region is not NTSC or MPAL, display error message until console is turned off
+ */
+void Check_RegionIsSupported(void) {
+    s32 regionSupported = false;
+
+    if ((osTvType == OS_TV_NTSC) || (osTvType == OS_TV_MPAL)) {
+        regionSupported = true;
+    }
+
+    if (!regionSupported) {
+        Check_DrawRegionLockErrorMessage();
+        osDestroyThread(NULL);
+        while (true) {}
+    }
+}

src/libultra/io/viblack.c

@@ -8,7 +8,7 @@ void osViBlack(u8 active) {
     if (active) {
         __osViNext->state |= 0x20;
     } else {
-        __osViNext->state &= 0xffdf;
+        __osViNext->state &= ~0x20;
     }
 
     __osRestoreInt(saveMask);

src/libultra/io/visetspecial.c

@@ -3,34 +3,33 @@
 void osViSetSpecialFeatures(u32 func) {
     register u32 saveMask = __osDisableInt();
 
-    if (func & 1) {
+    if (func & OS_VI_GAMMA_ON) {
-        __osViNext->features |= 8;
+        __osViNext->features |= OS_VI_GAMMA;
     }
-    if (func & 2) {
+    if (func & OS_VI_GAMMA_OFF) {
-        __osViNext->features &= ~8;
+        __osViNext->features &= ~OS_VI_GAMMA;
     }
-    if (func & 4) {
+    if (func & OS_VI_GAMMA_DITHER_ON) {
-        __osViNext->features |= 4;
+        __osViNext->features |= OS_VI_GAMMA_DITHER;
     }
-    if (func & 8) {
+    if (func & OS_VI_GAMMA_DITHER_OFF) {
+        __osViNext->features &= ~OS_VI_GAMMA_DITHER;
+    }
+    if (func & OS_VI_DIVOT_ON) {
 
-        __osViNext->features &= ~4;
+        __osViNext->features |= OS_VI_DIVOT;
     }
-    if (func & 0x10) {
+    if (func & OS_VI_DIVOT_OFF) {
 
-        __osViNext->features |= 0x10;
+        __osViNext->features &= ~OS_VI_DIVOT;
     }
-    if (func & 0x20) {
+    if (func & OS_VI_DITHER_FILTER_ON) {
-
+        __osViNext->features |= OS_VI_DITHER_FILTER;
-        __osViNext->features &= ~0x10;
+        __osViNext->features &= ~(OS_VI_UNK100 | OS_VI_UNK200);
     }
-    if (func & 0x40) {
+    if (func & OS_VI_DITHER_FILTER_OFF) {
-        __osViNext->features |= 0x10000;
+        __osViNext->features &= ~OS_VI_DITHER_FILTER;
-        __osViNext->features &= ~0x300;
+        __osViNext->features |= __osViNext->modep->comRegs.ctrl & (OS_VI_UNK100 | OS_VI_UNK200);
-    }
-    if (func & 0x80) {
-        __osViNext->features &= ~0x10000;
-        __osViNext->features |= __osViNext->modep->comRegs.ctrl & 0x300;
     }
     __osViNext->state |= 8;