completely redesign how user mode memory is allocated, fix a few smp and scheduler bugs, terminating a process now terminates the process, telemetry, optimize text editor, new font, new color scheme

code/kernel/hal/hal_screen.c

@@ -19,6 +19,9 @@ static int       gCursorX = 0, gCursorY = 0;
 #define FONT_W 8
 #define FONT_H 16
 
+#define SCREEN_DEFAULT_FG 0xCCCCCCu
+#define SCREEN_DEFAULT_BG 0x012456u
+
 // ---------------------------------------------------------------------------
 // 8x16 VGA font - printable ASCII only (glyph 0 = space = 0x20)
 // ---------------------------------------------------------------------------
@@ -113,28 +116,36 @@ static void ScreenBlit(int x, int y, int w, int h, const uint32_t* pixels) {
 static void ScreenGetSize(int* w, int* h) { *w = gWidth; *h = gHeight; }
 
 static void ScreenScroll(int lines) {
-    if (lines <= 0 || lines >= gHeight) { ScreenClear(0); return; }
+    if (lines <= 0)
+        return;
+    if (lines >= gHeight) {
+        ScreenClear(SCREEN_DEFAULT_BG);
+        return;
+    }
 
     size_t rowBytes = (size_t)gStride * sizeof(uint32_t);
     uint32_t* shadow = gBackbuffer ? gBackbuffer : gFb;
 
     memmove(shadow, shadow + lines * gStride,
             (size_t)(gHeight - lines) * rowBytes);
-    // Clear the revealed rows at the bottom.
-    memset(shadow + (gHeight - lines) * gStride, 0,
-           (size_t)lines * rowBytes);
+
+    // Fill the revealed rows with the console background.  Do not memset here:
+    // the background color is not zero.
+    uint32_t* fill = shadow + (gHeight - lines) * gStride;
+    for (int y = 0; y < lines; y++) {
+        for (int x = 0; x < gWidth; x++)
+            fill[y * gStride + x] = SCREEN_DEFAULT_BG;
+    }
 
     ScreenFlushRows(0, gHeight);
 }
 
 static void ScreenPutChar(char c, int x, int y, uint32_t fg, uint32_t bg) {
-    if ((unsigned char)c < 0x20 || (unsigned char)c > 0x7E) c = '?';
-    const uint8_t* glyph = Font8x16 + ((unsigned char)c - 0x20) * 16;
+    const uint8_t* glyph = Font8x16 + ((uint8_t)c * 16);
     for (int row = 0; row < 16; row++) {
         uint8_t bits = glyph[row];
         for (int col = 0; col < 8; col++) {
-            uint32_t color = (bits & (1 << col)) ? fg : bg; // i don't know why, i don't want to know why
-            // i shouldn't have to wonder why but the font is backwards unless we do this terriblness
+            uint32_t color = (bits & (0x80u >> col)) ? fg : bg;
             PutPixelRaw(x + col, y + row, color);
         }
     }
@@ -321,5 +332,5 @@ void HalScreenInitialize(void* (*AllocatePool)(size_t size), uintptr_t fb, int w
     out->PrintChar = ScreenPrintChar;
     out->DrawCursor = HalScreenDrawCursor;
     out->EraseCursor = HalScreenEraseCursor;
-    ScreenClear(0x000000);
+    ScreenClear(SCREEN_DEFAULT_BG);
 }