From 5813c416cff70e0b773e5151f07bf037fe692679 Mon Sep 17 00:00:00 2001
From: Bad Diode <bd@badd10de.dev>
Date: Mon, 14 Mar 2022 19:12:18 +0100
Subject: [PATCH] Fix TTY cursor and graphics mode

---
 Makefile   |  2 --
 src/main.c | 10 ++++++++++
 src/ppu.c  | 54 +++++++++++++++++++++++++++++++++++++++++++-----------
 3 files changed, 53 insertions(+), 13 deletions(-)

diff --git a/Makefile b/Makefile
index 8c56874..37b3802 100644
--- a/Makefile
+++ b/Makefile
@@ -48,8 +48,6 @@ $(UXN_ROM): $(UXN_ASM)
 	./$(UXN_ASM) $(TAL_SRC) $(UXN_ROM)
 
 run: $(BIN) $(UXN_ROM)
-	# NOTE: This should probably be done on the C code.
-	# echo 0 > /sys/class/graphics/fbcon/cursor_blink
 	./$(BIN) $(UXN_ROM)
 
 clean:
diff --git a/src/main.c b/src/main.c
index fcd42a4..29c4d5e 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,4 +1,5 @@
 #include <errno.h>
+#include <signal.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -24,6 +25,13 @@ static Device *devmouse;
 
 typedef struct timespec Time;
 
+void
+halt(int stub) {
+    (void)stub;
+    set_tty(false);
+    exit(EXIT_SUCCESS);
+}
+
 Time
 time_now(){
     struct timespec t;
@@ -446,6 +454,8 @@ load_rom(char *file_name) {
 
 void
 init_uxn(Uxn *u, char *file_name) {
+    signal(SIGINT, halt);
+
     // Setup UXN memory.
 	uxn_boot(u, calloc(0x10000, sizeof(u8)));
 
diff --git a/src/ppu.c b/src/ppu.c
index ff93ec1..aa99ed8 100644
--- a/src/ppu.c
+++ b/src/ppu.c
@@ -4,6 +4,7 @@
 
 #include <linux/fb.h>
 #include <sys/ioctl.h>
+#include <sys/kd.h>
 #include <sys/mman.h>
 
 #include "ppu.h"
@@ -89,6 +90,46 @@ redraw_screen(void) {
     }
 }
 
+static struct termios prev_t;
+
+void
+set_tty(bool graphics) {
+    // Disable TTY echo and set graphics mode.
+    int tty = open("/dev/tty0", O_RDWR);
+    if (!tty) {
+        fprintf(stderr,"error: couldn't open tty\n");
+        exit(EXIT_FAILURE);
+    }
+
+    if (graphics) {
+        if (ioctl(tty, KDSETMODE, KD_GRAPHICS)) {
+            fprintf(stderr,"error: setting graphics mode failed\n");
+            exit(EXIT_FAILURE);
+        }
+        struct termios t;
+        if (tcgetattr(STDIN_FILENO, &t)) {
+            fprintf(stderr, "error: couldn't disable terminal echo\n");
+            exit(EXIT_FAILURE);
+        }
+        prev_t = t;
+        t.c_lflag &= ~((tcflag_t) ECHO);
+        if (tcsetattr(STDIN_FILENO, TCSANOW, &t)) {
+            fprintf(stderr, "error: couldn't disable terminal echo\n");
+            exit(EXIT_FAILURE);
+        }
+    } else {
+        if (ioctl(tty, KDSETMODE, KD_TEXT)) {
+            fprintf(stderr,"error: setting text mode failed\n");
+            exit(EXIT_FAILURE);
+        }
+        if (tcsetattr(STDIN_FILENO, TCSANOW, &prev_t)) {
+            fprintf(stderr, "error: couldn't restore terminal attributes\n");
+            exit(EXIT_FAILURE);
+        }
+    }
+    close(tty);
+}
+
 int
 ppu_init(void) {
     // Open frambuffer and get the size.
@@ -122,17 +163,8 @@ ppu_init(void) {
         exit(EXIT_FAILURE);
     }
 
-    // Disable echo.
-    struct termios t;
-    if (tcgetattr(STDIN_FILENO, &t)) {
-        fprintf(stderr, "error: couldn't disable terminal echo\n");
-        exit(EXIT_FAILURE);
-    }
-    t.c_lflag &= ~((tcflag_t) ECHO);
-    if (tcsetattr(STDIN_FILENO, TCSANOW, &t)) {
-        fprintf(stderr, "error: couldn't disable terminal echo\n");
-        exit(EXIT_FAILURE);
-    }
+    // Prepare TTY for graphics mode.
+    set_tty(true);
 
     // Initialize default palette.
     palette[0] = 0x444444;