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/user/apps/edit/edit.c

@@ -18,6 +18,8 @@
 #define MAX_LINE  256
 #define PATH_MAX2 260
 #define MSG_MAX   160
+#define MAX_SCREEN_COLS 256
+#define MAX_SCREEN_ROWS 128
 
 #define COL_BG      0x000000u
 #define COL_FG      0xC8C8C8u
@@ -61,8 +63,55 @@ static bool gQuitArmed = false;
 static char gFilename[PATH_MAX2] = "untitled.txt";
 static char gMessage[MSG_MAX] = "ready";
 
+typedef struct SCREEN_CELL {
+    char c;
+    uint32_t fg;
+    uint32_t bg;
+} SCREEN_CELL;
+
+static SCREEN_CELL gScreenCache[MAX_SCREEN_COLS * MAX_SCREEN_ROWS];
+static bool gScreenCacheValid = false;
+
+static void invalidate_screen_cache(void) {
+    gScreenCacheValid = false;
+}
+
+static void update_screen_size(void) {
+    int pxW = 0, pxH = 0;
+    int oldCols = gCols;
+    int oldRows = gRows;
+
+    if (SysScreenGetSize(&pxW, &pxH) == 0 && pxW > 0 && pxH > 0) {
+        gCols = pxW / GLYPH_W;
+        gRows = pxH / GLYPH_H;
+
+        if (gCols < 20) gCols = 20;
+        if (gRows < 5)  gRows = 5;
+        if (gCols > MAX_SCREEN_COLS) gCols = MAX_SCREEN_COLS;
+        if (gRows > MAX_SCREEN_ROWS) gRows = MAX_SCREEN_ROWS;
+    }
+
+    if (gCols != oldCols || gRows != oldRows)
+        invalidate_screen_cache();
+}
+
 static void put_cell(int col, int row, char c, uint32_t fg, uint32_t bg) {
-    SysScreenPutChar(c ? c : ' ', col * GLYPH_W, row * GLYPH_H, fg, bg);
+    if (col < 0 || row < 0 || col >= gCols || row >= gRows)
+        return;
+
+    if (!c) c = ' ';
+
+    if (col < MAX_SCREEN_COLS && row < MAX_SCREEN_ROWS) {
+        SCREEN_CELL* cell = &gScreenCache[row * MAX_SCREEN_COLS + col];
+        if (gScreenCacheValid && cell->c == c && cell->fg == fg && cell->bg == bg)
+            return;
+
+        cell->c = c;
+        cell->fg = fg;
+        cell->bg = bg;
+    }
+
+    SysScreenPutChar(c, col * GLYPH_W, row * GLYPH_H, fg, bg);
 }
 
 static void clear_row(int row, uint32_t bg) {
@@ -151,13 +200,7 @@ static void ensure_visible(void) {
 }
 
 static void render(void) {
-    int pxW = 0, pxH = 0;
-    if (SysScreenGetSize(&pxW, &pxH) == 0 && pxW > 0 && pxH > 0) {
-        gCols = pxW / GLYPH_W;
-        gRows = pxH / GLYPH_H;
-        if (gCols < 20) gCols = 20;
-        if (gRows < 5)  gRows = 5;
-    }
+    update_screen_size();
 
     clamp_cursor();
     ensure_visible();
@@ -172,28 +215,40 @@ static void render(void) {
     append_str(status, sizeof(status), &p, ", Col ");
     append_u32(status, sizeof(status), &p, (uint32_t)(gCx + 1));
 
-    clear_row(0, COL_STATUS);
-    draw_text(0, 0, status, COL_STATUSF, COL_STATUS);
+    size_t statusLen = p;
+    for (int sx = 0; sx < gCols; sx++) {
+        char c = ((size_t)sx < statusLen) ? status[sx] : ' ';
+        put_cell(sx, 0, c, COL_STATUSF, COL_STATUS);
+    }
 
     int textRows = gRows - 2;
     for (int sy = 0; sy < textRows; sy++) {
         int row = sy + 1;
         int li = gTop + sy;
-        clear_row(row, COL_BG);
-        if (li >= gLineCount) continue;
 
-        LINE* ln = &gLines[li];
         for (int sx = 0; sx < gCols; sx++) {
             int ci = gLeft + sx;
-            char c = (ci < ln->len) ? ln->text[ci] : ' ';
-            bool atCursor = (li == gCy && ci == gCx);
+            char c = ' ';
+            bool atCursor = false;
+
+            if (li < gLineCount) {
+                LINE* ln = &gLines[li];
+                c = (ci < ln->len) ? ln->text[ci] : ' ';
+                atCursor = (li == gCy && ci == gCx);
+            }
+
             put_cell(sx, row, c, atCursor ? COL_CURSORF : COL_FG,
                               atCursor ? COL_CURSOR  : COL_BG);
         }
     }
 
-    clear_row(gRows - 1, COL_STATUS);
-    draw_text(0, gRows - 1, gMessage, COL_STATUSF, COL_STATUS);
+    size_t messageLen = strlen(gMessage);
+    for (int sx = 0; sx < gCols; sx++) {
+        char c = ((size_t)sx < messageLen) ? gMessage[sx] : ' ';
+        put_cell(sx, gRows - 1, c, COL_STATUSF, COL_STATUS);
+    }
+
+    gScreenCacheValid = true;
 }
 
 static void insert_char_at_cursor(char c) {
@@ -481,8 +536,10 @@ int main(void) {
     parse_filename_from_cmdline();
     load_file();
     SysScreenClear(COL_BG);
+    invalidate_screen_cache();
     editor_loop();
-    SysScreenClear(COL_BG);
+    SysScreenClear(0x012456);
+    invalidate_screen_cache();
     print("edit: goodbye\n");
     SysExitProcess(0);
     return 0;