fix(userland): Fix 'clear' command, backspace keycodes (0x7F/0x08), serial keyboard input & make run target

- Add 'clear' and 'cls' builtin handlers in LazyBox shell
- Output ANSI \033[2J\033[H sequence on tty_clear() to clear serial/UART terminals
- Support both ASCII 0x7F (DEL) and 0x08 (BS) for Backspace in shell and nano editor
- Connect 16550 serial input to keyboard_get_key() on x86_64 for headless terminals
- Add ANSI escape sequence decoding for arrow keys (Up/Down/Left/Right/Home/End/Del)
- Update Makefile 'make run' and 'make qemu' with -display none for smooth terminal execution
- Add 'make run-gui' target for optional graphical SDL/GTK window

Makefile

@@ -53,7 +53,7 @@ ifeq ($(ARCH), x86_64)
     TARGET        = $(IMAGE)
     QEMU_CMD      = qemu-system-x86_64 -drive format=raw,file=$(IMAGE) \
                     -netdev user,id=net0,hostfwd=tcp::2222-:22,hostfwd=tcp::8080-:80 \
-                    -device e1000,netdev=net0 -serial stdio
+                    -device e1000,netdev=net0 -serial stdio -display none
 
 else ifneq ($(filter $(ARCH), aarch64 arm64),)
     CROSS_COMPILE ?= aarch64-linux-gnu-
@@ -375,6 +375,17 @@ $(IMAGE): $(BUILD_DIR)/boot/boot.bin $(BUILD_DIR)/boot/stage2.bin $(BUILD_DIR)/k
 run qemu: $(TARGET)
 	$(QEMU_CMD)
 
+run-gui: $(TARGET)
+ifeq ($(ARCH), x86_64)
+	qemu-system-x86_64 -drive format=raw,file=$(IMAGE) \
+		-netdev user,id=net0,hostfwd=tcp::2222-:22,hostfwd=tcp::8080-:80 \
+		-device e1000,netdev=net0 -serial stdio
+else ifneq ($(filter $(ARCH), aarch64 arm64),)
+	qemu-system-aarch64 -M virt -cpu cortex-a57 -m 128M -kernel $(BUILD_DIR)/kernel.elf -serial stdio
+else
+	qemu-system-arm -M virt -cpu cortex-a15 -m 128M -kernel $(BUILD_DIR)/kernel.elf -serial stdio
+endif
+
 run-server: $(IMAGE)
 	qemu-system-x86_64 -drive format=raw,file=$(IMAGE) \
 		-netdev user,id=net0,hostfwd=tcp::2222-:22,hostfwd=tcp::8080-:80 \

drivers/char/keyboard.c

@@ -2,6 +2,14 @@
 #include <drivers/tty.h>
 #include <arch/arch.h>
 
+#if defined(__x86_64__)
+#include <drivers/serial.h>
+#elif defined(__aarch64__)
+#include <arch/aarch64/uart.h>
+#elif defined(__arm__) || defined(__armv8i__)
+#include <arch/armv8i/uart.h>
+#endif
+
 #define KEYBOARD_DATA_PORT    0x60
 #define KEYBOARD_STATUS_PORT  0x64
 #define KEYBOARD_BUFFER_SIZE  128
@@ -123,14 +131,10 @@ void keyboard_init(void) {
 #endif
 }
 
-#if defined(__aarch64__)
-#include <arch/aarch64/uart.h>
-#elif defined(__arm__) || defined(__armv8i__)
-#include <arch/armv8i/uart.h>
-#endif
-
 bool keyboard_has_key(void) {
-#if defined(__aarch64__) || defined(__arm__) || defined(__armv8i__)
+#if defined(__x86_64__)
+    if (serial_received()) return true;
+#elif defined(__aarch64__) || defined(__arm__) || defined(__armv8i__)
     if (uart_pl011_has_data()) return true;
 #endif
     return buffer_head != buffer_tail;
@@ -140,13 +144,75 @@ uint16_t keyboard_get_key(void) {
     while (!keyboard_has_key()) {
         arch_halt();
     }
-#if defined(__aarch64__) || defined(__arm__) || defined(__armv8i__)
+
+#if defined(__x86_64__)
+    if (serial_received()) {
+        char c = serial_read_char();
+        if ((uint8_t)c == 0x1B) { // Escape sequence
+            for (volatile int t = 0; t < 2000; t++) {
+                if (serial_received()) {
+                    char c2 = serial_read_char();
+                    if (c2 == '[') {
+                        for (volatile int t2 = 0; t2 < 2000; t2++) {
+                            if (serial_received()) {
+                                char c3 = serial_read_char();
+                                if (c3 == 'A') return KEY_UP;
+                                if (c3 == 'B') return KEY_DOWN;
+                                if (c3 == 'C') return KEY_RIGHT;
+                                if (c3 == 'D') return KEY_LEFT;
+                                if (c3 == 'H') return KEY_HOME;
+                                if (c3 == 'F') return KEY_END;
+                                if (c3 == '3') {
+                                    if (serial_received() && serial_read_char() == '~') return KEY_DELETE;
+                                }
+                                break;
+                            }
+                        }
+                    }
+                    break;
+                }
+            }
+            return 0x1B;
+        }
+        if (c == '\r') c = '\n';
+        if ((uint8_t)c == 0x7F || c == 0x08) c = '\b';
+        return (uint16_t)(uint8_t)c;
+    }
+#elif defined(__aarch64__) || defined(__arm__) || defined(__armv8i__)
     if (uart_pl011_has_data()) {
         char c = uart_pl011_getc();
+        if ((uint8_t)c == 0x1B) { // Escape sequence
+            for (volatile int t = 0; t < 2000; t++) {
+                if (uart_pl011_has_data()) {
+                    char c2 = uart_pl011_getc();
+                    if (c2 == '[') {
+                        for (volatile int t2 = 0; t2 < 2000; t2++) {
+                            if (uart_pl011_has_data()) {
+                                char c3 = uart_pl011_getc();
+                                if (c3 == 'A') return KEY_UP;
+                                if (c3 == 'B') return KEY_DOWN;
+                                if (c3 == 'C') return KEY_RIGHT;
+                                if (c3 == 'D') return KEY_LEFT;
+                                if (c3 == 'H') return KEY_HOME;
+                                if (c3 == 'F') return KEY_END;
+                                if (c3 == '3') {
+                                    if (uart_pl011_has_data() && uart_pl011_getc() == '~') return KEY_DELETE;
+                                }
+                                break;
+                            }
+                        }
+                    }
+                    break;
+                }
+            }
+            return 0x1B;
+        }
         if (c == '\r') c = '\n';
+        if ((uint8_t)c == 0x7F || c == 0x08) c = '\b';
         return (uint16_t)(uint8_t)c;
     }
 #endif
+
     uint16_t key = key_buffer[buffer_tail];
     buffer_tail = (buffer_tail + 1) % KEYBOARD_BUFFER_SIZE;
     return key;

drivers/char/tty.c

@@ -1,6 +1,7 @@
 #include <drivers/tty.h>
 #include <drivers/vga.h>
 #include <lib/string.h>
+#include <kernel/printk.h>
 
 typedef struct {
     uint16_t buffer[TTY_HEIGHT][TTY_WIDTH];
@@ -42,7 +43,7 @@ static void tty_scroll(tty_t* t) {
         }
     }
     for (int x = 0; x < TTY_WIDTH; x++) {
-        t->buffer[TTY_HEIGHT - 1][x] = vga_entry(' ', t->current_color);
+        t->buffer[TTY_HEIGHT - 1][x] = vga_entry(' ', t->current_color ? t->current_color : 0x07);
     }
     t->cursor_row = TTY_HEIGHT - 1;
 }
@@ -51,12 +52,15 @@ void tty_clear(void) {
     tty_t* t = &ttys[current_tty];
     for (int y = 0; y < TTY_HEIGHT; y++) {
         for (int x = 0; x < TTY_WIDTH; x++) {
-            t->buffer[y][x] = vga_entry(' ', t->current_color);
+            t->buffer[y][x] = vga_entry(' ', t->current_color ? t->current_color : 0x07);
         }
     }
     t->cursor_row = 0;
     t->cursor_col = 0;
     tty_render_current();
+
+    // Send standard ANSI terminal clear screen sequence to serial / UART
+    printk("\033[2J\033[H");
 }
 
 void tty_set_cursor(int row, int col) {
@@ -74,7 +78,7 @@ void tty_write(const char* data, size_t size) {
     for (size_t i = 0; i < size; i++) {
         char c = data[i];
 
-        // Basic ANSI escape sequence parser (e.g. \033[31m)
+        // ANSI escape sequence parser
         if (c == '\033' && i + 1 < size && data[i + 1] == '[') {
             i += 2;
             int code = 0;
@@ -91,7 +95,7 @@ void tty_write(const char* data, size_t size) {
                 else if (code == 35) t->current_color = 0x05; // Magenta
                 else if (code == 36) t->current_color = 0x03; // Cyan
                 else if (code == 37) t->current_color = 0x07; // White
-                else if (code == 90) t->current_color = 0x08; // Bright Black (Dark Grey)
+                else if (code == 90) t->current_color = 0x08; // Bright Black
                 else if (code == 91) t->current_color = 0x0C; // Bright Red
                 else if (code == 92) t->current_color = 0x0A; // Bright Green
                 else if (code == 93) t->current_color = 0x0E; // Bright Yellow
@@ -102,8 +106,21 @@ void tty_write(const char* data, size_t size) {
             } else if (i < size && data[i] == 'K') {
                 // Clear from cursor to end of line
                 for (int x = t->cursor_col; x < TTY_WIDTH; x++) {
-                    t->buffer[t->cursor_row][x] = vga_entry(' ', t->current_color);
+                    t->buffer[t->cursor_row][x] = vga_entry(' ', t->current_color ? t->current_color : 0x07);
                 }
+            } else if (i < size && data[i] == 'J') {
+                // Clear entire screen buffer
+                for (int y = 0; y < TTY_HEIGHT; y++) {
+                    for (int x = 0; x < TTY_WIDTH; x++) {
+                        t->buffer[y][x] = vga_entry(' ', t->current_color ? t->current_color : 0x07);
+                    }
+                }
+                t->cursor_row = 0;
+                t->cursor_col = 0;
+            } else if (i < size && data[i] == 'H') {
+                // Cursor Home
+                t->cursor_row = 0;
+                t->cursor_col = 0;
             } else if (i < size && data[i] == 'D') {
                 // Move cursor left
                 if (t->cursor_col > 0) t->cursor_col--;
@@ -132,10 +149,10 @@ void tty_write(const char* data, size_t size) {
         } else if (c == '\b') {
             if (t->cursor_col > 0) {
                 t->cursor_col--;
-                t->buffer[t->cursor_row][t->cursor_col] = vga_entry(' ', t->current_color);
+                t->buffer[t->cursor_row][t->cursor_col] = vga_entry(' ', t->current_color ? t->current_color : 0x07);
             }
         } else {
-            t->buffer[t->cursor_row][t->cursor_col] = vga_entry(c, t->current_color);
+            t->buffer[t->cursor_row][t->cursor_col] = vga_entry(c, t->current_color ? t->current_color : 0x07);
             if (++t->cursor_col >= TTY_WIDTH) {
                 t->cursor_col = 0;
                 if (++t->cursor_row >= TTY_HEIGHT) {

include/config/autoconf.h

@@ -2,8 +2,8 @@
 #ifndef _AUTOCONF_H
 #define _AUTOCONF_H
 
-#define CONFIG_ARCH "armv8i"
-#define CONFIG_ARCH_ARMV8I 1
+#define CONFIG_ARCH "x86_64"
+#define CONFIG_ARCH_X86_64 1
 #define CONFIG_BPF_VM 1
 #define CONFIG_DRV_AHCI 1
 #define CONFIG_DRV_ATA 1

kernel/main.c

@@ -195,9 +195,6 @@ static void subos_modular_core_boot(void) {
     printk(ANSI_BRIGHT_GREEN "ACTIVE\n" ANSI_RESET);
 
     // Launch Shell
-#if defined(__x86_64__)
-    tty_clear();
-#endif
     shell_run();
 
     while (1) {

userland/lazybox/nano.c

@@ -287,7 +287,8 @@ int nano_main(int argc, char** argv) {
                 }
                 break;
 
-            case '\b': // Backspace
+            case '\b': // Backspace (0x08)
+            case 0x7F: // DEL
                 if (nano_cursor_col > 0) {
                     memmove(&nano_lines[nano_cursor_row][nano_cursor_col - 1],
                             &nano_lines[nano_cursor_row][nano_cursor_col],

userland/lazybox/shell.c

@@ -287,6 +287,8 @@ static void shell_process(const char* cmd) {
             int idx = (history_head - history_count + i + HISTORY_SIZE) % HISTORY_SIZE;
             printk("  %2d: %s\n", i + 1, history[idx]);
         }
+    } else if (strcmp(argv[0], "clear") == 0 || strcmp(argv[0], "cls") == 0) {
+        tty_clear();
     } else if (strcmp(argv[0], "reboot") == 0) {
         printk(ANSI_YELLOW "Rebooting...\n" ANSI_RESET);
         pit_sleep(200);
@@ -392,7 +394,7 @@ void shell_run(void) {
                 printk("%s%s", prompt, cmd_buffer);
                 continue;
             }
-            if (c == '\b') {
+            if (c == '\b' || (unsigned char)c == 0x7F || c == 0x08) {
                 if (cursor_pos > 0) {
                     for (size_t i = cursor_pos - 1; i < cmd_len - 1; i++) cmd_buffer[i] = cmd_buffer[i + 1];
                     cmd_len--;
@@ -400,6 +402,7 @@ void shell_run(void) {
                     cmd_buffer[cmd_len] = '\0';
                     redraw_line(prompt, cmd_buffer, cmd_len, cursor_pos);
                 }
+                continue;
             } else if (c == '\t') {
                 if (cmd_len > 0) {
                     int matches = 0;