logger fixes

core/fbcon.c

@@ -26,6 +26,7 @@ enum esc_state {
 
 static struct {
     struct boot_framebuffer fb;
+    uint32_t* back;
     uint32_t fg, bg;
     size_t cols, rows;
     size_t offset_x, offset_y;
@@ -37,6 +38,15 @@ static inline uint8_t* fb_ptr() {
     return HHDM_PTR(fbcon.fb.base);
 }
 
+static inline uint32_t* back_row(size_t y) {
+    return fbcon.back + y * fbcon.fb.width;
+}
+
+static void flush_rect(size_t x, size_t y, size_t w, size_t h) {
+    for (size_t j = 0; j < h; j++)
+        memcpy((uint32_t*)(fb_ptr() + (y + j) * fbcon.fb.pitch) + x, back_row(y + j) + x, w * sizeof(uint32_t));
+}
+
 static uint32_t pack_color(uint32_t rgb) {
     const struct boot_framebuffer* fb = &fbcon.fb;
     uint32_t r = (rgb >> 16) & 0xff;
@@ -48,10 +58,11 @@ static uint32_t pack_color(uint32_t rgb) {
 
 static void fill_rect(size_t x, size_t y, size_t w, size_t h, uint32_t color) {
     for (size_t j = 0; j < h; j++) {
-        uint32_t* row = (uint32_t*)(fb_ptr() + (y + j) * fbcon.fb.pitch) + x;
+        uint32_t* row = back_row(y + j) + x;
         for (size_t i = 0; i < w; i++)
             row[i] = color;
     }
+    flush_rect(x, y, w, h);
 }
 
 static void clear_screen() {
@@ -65,19 +76,25 @@ static void draw_glyph(size_t col, size_t row, uint8_t ch) {
     size_t y = fbcon.offset_y + row * FONT_HEIGHT;
 
     for (size_t j = 0; j < FONT_HEIGHT; j++) {
-        uint32_t* line = (uint32_t*)(fb_ptr() + (y + j) * fbcon.fb.pitch) + x;
+        uint32_t* line = back_row(y + j) + x;
         for (size_t i = 0; i < FONT_WIDTH; i++)
             line[i] = (glyph[j] & (0x80 >> i)) ? fbcon.fg : fbcon.bg;
     }
+    flush_rect(x, y, FONT_WIDTH, FONT_HEIGHT);
 }
 
 static void scroll_up() {
-    const size_t pitch = fbcon.fb.pitch;
+    const size_t width = fbcon.fb.width;
     const size_t text_y = fbcon.offset_y;
     const size_t text_h = fbcon.rows * FONT_HEIGHT;
 
-    memmove(fb_ptr() + text_y * pitch, fb_ptr() + (text_y + FONT_HEIGHT) * pitch, (text_h - FONT_HEIGHT) * pitch);
-    fill_rect(0, text_y + text_h - FONT_HEIGHT, fbcon.fb.width, FONT_HEIGHT, fbcon.bg);
+    memmove(back_row(text_y), back_row(text_y + FONT_HEIGHT), (text_h - FONT_HEIGHT) * width * sizeof(uint32_t));
+    for (size_t j = text_y + text_h - FONT_HEIGHT; j < text_y + text_h; j++) {
+        uint32_t* row = back_row(j);
+        for (size_t i = 0; i < width; i++)
+            row[i] = fbcon.bg;
+    }
+    flush_rect(0, text_y, width, text_h);
 }
 
 static void newline() {
@@ -178,6 +195,10 @@ void fbcon_init(struct boot_info* info) {
             return;
     }
 
+    fbcon.back = mem_alloc(fb->width * fb->height * sizeof(uint32_t), ALLOC_NOZERO);
+    if (!fbcon.back)
+        return;
+
     console_register(&fbcon_con);
 }
 INIT_TASK(fbcon_stage, "core.fbcon", fbcon_init);