rosalina: add brightness control menu

sysmodules/rosalina/include/draw.h

@@ -54,6 +54,9 @@
 #define GPU_TRANSFER_CNT            REG32(0x10400C18)
 #define GPU_CMDLIST_CNT             REG32(0x104018F0)
 
+#define LCD_TOP_BRIGHTNESS          REG32(0x10202240)
+#define LCD_BOT_BRIGHTNESS          REG32(0x10202A40)
+
 #define FB_BOTTOM_VRAM_ADDR         ((void *)0x1F48F000) // cached
 #define FB_BOTTOM_VRAM_PA           0x1848F000
 #define FB_BOTTOM_SIZE              (320 * 240 * 2)

sysmodules/rosalina/include/menu.h

@@ -60,6 +60,7 @@ typedef struct Menu {
     MenuItem items[0x40];
 } Menu;
 
+extern bool isN3DS;
 extern bool menuShouldExit;
 extern bool preTerminationRequested;
 extern Handle preTerminationEvent;

sysmodules/rosalina/include/menus.h

@@ -33,6 +33,7 @@
 extern Menu rosalinaMenu;
 
 void RosalinaMenu_TakeScreenshot(void);
+void RosalinaMenu_ChangeScreenBrightness(void);
 void RosalinaMenu_ShowCredits(void);
 void RosalinaMenu_ProcessList(void);
 void RosalinaMenu_PowerOff(void);

sysmodules/rosalina/include/process_patches.h

@@ -30,3 +30,4 @@
 #include "menu.h"
 
 Result OpenProcessByName(const char *name, Handle *h);
+Result PatchProcessByName(const char *name, Result (*func)(u32 size));

sysmodules/rosalina/source/menu.c

@@ -151,7 +151,6 @@ MyThread *menuCreateThread(void)
     return &menuThread;
 }
 
-extern bool isN3DS;
 u32 menuCombo;
 
 void menuThreadMain(void)
@@ -159,7 +158,7 @@ void menuThreadMain(void)
     if(!isN3DS)
     {
         rosalinaMenu.nbItems--;
-        for(u32 i = 6; i <= rosalinaMenu.nbItems; i++)
+        for(u32 i = 7; i <= rosalinaMenu.nbItems; i++)
             rosalinaMenu.items[i] = rosalinaMenu.items[i+1];
     }
     else

sysmodules/rosalina/source/menus.c

@@ -38,12 +38,14 @@
 #include "ifile.h"
 #include "memory.h"
 #include "fmt.h"
+#include "process_patches.h"
 
 Menu rosalinaMenu = {
     "Rosalina menu",
-    .nbItems = 11,
+    .nbItems = 12,
     {
         { "Take screenshot", METHOD, .method = &RosalinaMenu_TakeScreenshot },
+        { "Change screen brightness", METHOD, .method = &RosalinaMenu_ChangeScreenBrightness },
         { "Cheats...", METHOD, .method = &RosalinaMenu_Cheats },
         { "Process list", METHOD, .method = &RosalinaMenu_ProcessList },
         { "Debugger options...", MENU, .menu = &debuggerMenu },
@@ -119,6 +121,109 @@ void RosalinaMenu_Reboot(void)
     while(!menuShouldExit);
 }
 
+static u32 gspPatchAddrN3ds, gspPatchValuesN3ds[2];
+static bool gspPatchDoneN3ds;
+
+static Result RosalinaMenu_PatchN3dsGspForBrightness(u32 size)
+{
+    u32 *off = (u32 *)0x00100000;
+    u32 *end = (u32 *)(0x00100000 + size);
+
+    for (; off < end && (off[0] != 0xE92D4030 || off[1] != 0xE1A04000 || off[2] != 0xE2805C01 || off[3] != 0xE5D0018C); off++);
+
+    if (off >= end) {
+        return -1;
+    }
+
+    gspPatchAddrN3ds = (u32)off;
+    gspPatchValuesN3ds[0] = off[26];
+    gspPatchValuesN3ds[1] = off[50];
+
+    // NOP brightness changing in GSP
+    off[26] = 0xE1A00000;
+    off[50] = 0xE1A00000;
+
+    return 0;
+}
+static Result RosalinaMenu_RevertN3dsGspPatch(u32 size)
+{
+    (void)size;
+
+    u32 *off = (u32 *)gspPatchAddrN3ds;
+    off[26] = gspPatchValuesN3ds[0];
+    off[50] = gspPatchValuesN3ds[1];
+
+    return 0;
+}
+
+void RosalinaMenu_ChangeScreenBrightness(void)
+{
+    Result patchResult = 0;
+    if (isN3DS && !gspPatchDoneN3ds)
+    {
+        patchResult = PatchProcessByName("gsp", RosalinaMenu_PatchN3dsGspForBrightness);
+        gspPatchDoneN3ds = R_SUCCEEDED(patchResult);
+    }
+
+    Draw_Lock();
+    Draw_ClearFramebuffer();
+    Draw_FlushFramebuffer();
+    Draw_Unlock();
+
+    do
+    {
+        // Assume the current brightness for both screens are the same.
+        s32 brightness = (s32)(LCD_TOP_BRIGHTNESS & 0xFF);
+
+        Draw_Lock();
+        Draw_DrawString(10, 10, COLOR_TITLE, "Rosalina menu");
+        u32 posY = 30;
+        posY = Draw_DrawFormattedString(10, posY, COLOR_WHITE, "Current brightness (0..255): %3lu\n\n", brightness);
+        if (R_SUCCEEDED(patchResult))
+        {
+            posY = Draw_DrawString(10, posY, COLOR_WHITE, "Press Up/Down for +-1, Right/Left for +-10.\n");
+            posY = Draw_DrawString(10, posY, COLOR_WHITE, "Press Y to revert the GSP patch and exit.\n\n");
+
+            posY = Draw_DrawString(10, posY, COLOR_RED, "WARNING: \n");
+            posY = Draw_DrawString(10, posY, COLOR_WHITE, "  * very high values might damage your screens\n");
+            posY = Draw_DrawString(10, posY, COLOR_WHITE, "  * normal brightness mngmt. is now broken on N3DS.\nYou'll need to press Y to revert");
+        }
+        else
+            Draw_DrawFormattedString(10, posY, COLOR_WHITE, "Failed to patch GSP (0x%08lx).", (u32)patchResult);
+
+        Draw_FlushFramebuffer();
+        Draw_Unlock();
+
+        u32 pressed = waitInputWithTimeout(1000);
+
+        if ((pressed & DIRECTIONAL_KEYS) && R_SUCCEEDED(patchResult))
+        {
+            if (pressed & KEY_UP)
+                brightness += 1;
+            else if (pressed & KEY_DOWN)
+                brightness -= 1;
+            else if (pressed & KEY_RIGHT)
+                brightness += 10;
+            else if (pressed & KEY_LEFT)
+                brightness -= 10;
+
+            brightness = brightness < 0 ? 0 : brightness;
+            brightness = brightness > 255 ? 255 : brightness;
+            LCD_TOP_BRIGHTNESS = (u32)brightness;
+            LCD_BOT_BRIGHTNESS = (u32)brightness;
+        }
+        else if ((pressed & KEY_Y) && gspPatchDoneN3ds)
+        {
+            patchResult = PatchProcessByName("gsp", RosalinaMenu_RevertN3dsGspPatch);
+            gspPatchDoneN3ds = !R_SUCCEEDED(patchResult);
+            return;
+        }
+        else if (pressed & KEY_B)
+            return;
+    }
+    while (!menuShouldExit);
+}
+
 void RosalinaMenu_PowerOff(void) // Soft shutdown.
 {
     Draw_Lock();

sysmodules/rosalina/source/process_patches.c

@@ -59,7 +59,7 @@ Result OpenProcessByName(const char *name, Handle *h)
     return 0;
 }
 
-/*static u32 ProcessPatchesMenu_PatchUnpatchProcessByName(const char *name, Result (*func)(u32 size))
+Result PatchProcessByName(const char *name, Result (*func)(u32 size))
 {
     Result res;
     Handle processHandle;
@@ -75,4 +75,4 @@ Result OpenProcessByName(const char *name, Handle *h)
 
     svcUnmapProcessMemoryEx(processHandle, 0x00100000, textTotalRoundedSize);
     return res;
-}*/
+}