feat: VKILL line kill, c_iflag ICRNL/IGNCR/INLCR, TCSETSW/TCSETSF

- Add VKILL (Ctrl-U) handling in canonical mode: erases entire
  line buffer with visual backspace feedback
- Add c_iflag bits: ICRNL (default on), IGNCR, INLCR
- Add tty_iflag state variable, default ICRNL enabled
- c_iflag input translation runs before signal/canonical processing
- Replace hardcoded CR→NL conversion with c_iflag-based translation
- TCGETS now returns c_iflag; TCSETS now applies c_iflag mask
- Add TCSETSW (0x5403) and TCSETSF (0x5404) ioctl commands
  (treated same as TCSETS — no output queue to drain/flush)

20/20 smoke tests pass.

diff --git a/include/tty.h b/include/tty.h
index 0ec5089b02a70bd03d3fa1b6fadbe7f2ec29f9ee..c8deb98174461eab26588e857badf8447f96831d 100644 (file)
--- a/include/tty.h
+++ b/include/tty.h
@@ -30,12 +30,20 @@ struct winsize {
     uint16_t ws_ypixel;
 };
 
+/* c_lflag bits */
 enum {
     TTY_ICANON = 0x0002,
     TTY_ECHO   = 0x0008,
     TTY_ISIG   = 0x0001,
 };
 
+/* c_iflag bits */
+enum {
+    TTY_ICRNL  = 0x0100,  /* map CR to NL on input        */
+    TTY_IGNCR  = 0x0080,  /* ignore CR on input            */
+    TTY_INLCR  = 0x0040,  /* map NL to CR on input         */
+};
+
 /* c_oflag bits (POSIX) */
 enum {
     TTY_OPOST = 0x0001,

diff --git a/src/kernel/tty.c b/src/kernel/tty.c
index fe8d65a90cc6888586f0fb3080cf8d3687ca3e9d..fb8b0e425238c95f51ccfb46099169c83bfc1235 100644 (file)
--- a/src/kernel/tty.c
+++ b/src/kernel/tty.c
@@ -26,6 +26,7 @@ static uint32_t canon_tail = 0;
 
 static waitqueue_t tty_wq;
 
+static uint32_t tty_iflag = TTY_ICRNL;
 static uint32_t tty_lflag = TTY_ICANON | TTY_ECHO | TTY_ISIG;
 static uint32_t tty_oflag = TTY_OPOST | TTY_ONLCR;
 static uint8_t tty_cc[NCCS] = {
@@ -205,6 +206,8 @@ static void canon_push(char c) {
 enum {
     TTY_TCGETS = 0x5401,
     TTY_TCSETS = 0x5402,
+    TTY_TCSETSW = 0x5403,
+    TTY_TCSETSF = 0x5404,
     TTY_TIOCGPGRP = 0x540F,
     TTY_TIOCSPGRP = 0x5410,
     TTY_TIOCGWINSZ = 0x5413,
@@ -252,6 +255,7 @@ int tty_ioctl(uint32_t cmd, void* user_arg) {
         struct termios t;
         memset(&t, 0, sizeof(t));
         uintptr_t flags = spin_lock_irqsave(&tty_lock);
+        t.c_iflag = tty_iflag;
         t.c_lflag = tty_lflag;
         t.c_oflag = tty_oflag;
         for (int i = 0; i < NCCS; i++) t.c_cc[i] = tty_cc[i];
@@ -260,10 +264,11 @@ int tty_ioctl(uint32_t cmd, void* user_arg) {
         return 0;
     }
 
-    if (cmd == TTY_TCSETS) {
+    if (cmd == TTY_TCSETS || cmd == TTY_TCSETSW || cmd == TTY_TCSETSF) {
         struct termios t;
         if (copy_from_user(&t, user_arg, sizeof(t)) < 0) return -EFAULT;
         uintptr_t flags = spin_lock_irqsave(&tty_lock);
+        tty_iflag = t.c_iflag & (TTY_ICRNL | TTY_IGNCR | TTY_INLCR);
         tty_lflag = t.c_lflag & (TTY_ICANON | TTY_ECHO | TTY_ISIG);
         tty_oflag = t.c_oflag & (TTY_OPOST | TTY_ONLCR);
         for (int i = 0; i < NCCS; i++) tty_cc[i] = t.c_cc[i];
@@ -288,8 +293,17 @@ int tty_ioctl(uint32_t cmd, void* user_arg) {
 
 void tty_input_char(char c) {
     uintptr_t flags = spin_lock_irqsave(&tty_lock);
+    uint32_t iflag = tty_iflag;
     uint32_t lflag = tty_lflag;
 
+    /* c_iflag input translation */
+    if (c == '\r') {
+        if (iflag & TTY_IGNCR) { spin_unlock_irqrestore(&tty_lock, flags); return; }
+        if (iflag & TTY_ICRNL) c = '\n';
+    } else if (c == '\n') {
+        if (iflag & TTY_INLCR) c = '\r';
+    }
+
     enum { SIGINT_NUM = 2, SIGQUIT_NUM = 3, SIGTSTP_NUM = 20 };
 
     if (lflag & TTY_ISIG) {
@@ -341,7 +355,6 @@ void tty_input_char(char c) {
     }
 
     if ((lflag & TTY_ICANON) == 0) {
-        if (c == '\r') c = '\n';
         canon_push(c);
         wq_wake_one(&tty_wq);
         if (lflag & TTY_ECHO) {
@@ -362,7 +375,17 @@ void tty_input_char(char c) {
         return;
     }
 
-    if (c == '\r') c = '\n';
+    if (tty_cc[VKILL] && (uint8_t)c == tty_cc[VKILL]) {
+        if (lflag & TTY_ECHO) {
+            while (line_len > 0) {
+                line_len--;
+                kprintf("\b \b");
+            }
+        }
+        line_len = 0;
+        spin_unlock_irqrestore(&tty_lock, flags);
+        return;
+    }
 
     if (c == '\n') {
         if (lflag & TTY_ECHO) {