kernel

commit f01c70d6731b11269e4e5b6560deae5dfde9e0f4
parent 82084d59718d0cded62a753110d82b3c05f289fc
Author: evenfri <evenfri256@gmail.com>
Date:   Mon,  3 Aug 2026 21:23:10 +0800

fixes, add warnings, add tty scroll

Diffstat:
M
build/cc
 | 
2
++
M
dat.h
 | 
1
+
M
printk.c
 | 
4
+---
M
qemu-iso.sh
 | 
2
+-
M
qemu.sh
 | 
2
+-
M
syscall.c
 | 
2
++
M
tty.c
 | 
23
+++++++++++++++++++++--
M
user/isodir/boot/kernel
 | 
0

M
vfs.c
 | 
3
+++

9 files changed, 32 insertions(+), 7 deletions(-)
diff --git a/build/cc b/build/cc
@@ -5,5 +5,7 @@ exec i686-elf-gcc -c \
   -nostdlib \
   -ffreestanding \
   -fno-builtin \
+  -Wall \
+  -Wextra \
   -I"$kernel" \
   "$@"
diff --git a/dat.h b/dat.h
@@ -61,6 +61,7 @@ typedef void (*int_handler)();
 /* vfs */
 #define stdin 0
 #define stdout 1
+#define EOF (-1)
 
 /* syscalls */
 #define sys_read 0
diff --git a/printk.c b/printk.c
@@ -4,8 +4,6 @@
 #include <dat.h>
 #include <fns.h>
 
-#define EOF (-1)
-
 static char *utoa_hex(unsigned int num, char *buf, size_t bufsize) {
   char *p = buf + bufsize - 1;
   *p = '\0';
@@ -42,7 +40,7 @@ static char *itoa_dec(int num, char *buf, size_t bufsize) {
 }
 
 static bool print(const char* data, size_t length) {
-  if (vfs_write(stdout, (void*) data, length) == EOF)
+  if (vfs_write(stdout, (void*) data, length) == (size_t)EOF)
     return false;
   return true;
 }
diff --git a/qemu-iso.sh b/qemu-iso.sh
@@ -2,7 +2,7 @@
 
 set -e
 iso="./user/os.iso"
-mem="4M"
+mem="16M"
 
 ./iso.sh
 
diff --git a/qemu.sh b/qemu.sh
@@ -2,7 +2,7 @@
 
 set -e
 kernel_bin="o.kernel"
-mem="4M"
+mem="16M"
 
 exec qemu-system-i386 \
   -m "$mem" \
diff --git a/syscall.c b/syscall.c
@@ -9,6 +9,8 @@ void syscall_init() {
 
 int syscall_handler(int num, int arg1, int arg2,
     int arg3, int arg4, int arg5) {
+  (void)arg4;
+  (void)arg5;
   switch (num) {
     case sys_read:
       return vfs_read(arg1, (void*) arg2, arg3);
diff --git a/tty.c b/tty.c
@@ -34,13 +34,31 @@ void tty_init(void) {
   tty_clear();
 }
 
+void tty_scroll(void) {
+  /* move lines to line-1 */
+  for (int row = 1; row < vga_height; row++) {
+    for (int col = 0; col < vga_width; col++) {
+      size_t src_index = row * vga_width + col;
+      size_t dst_index = (row - 1) * vga_width + col;
+      tty_buffer[dst_index] = tty_buffer[src_index];
+    }
+  }
+  /* clear last line*/
+  uint16_t blank = ' ' | (tty_color << 8);
+  for (int col = 0; col < vga_width; col++) {
+    size_t index = (vga_height - 1) * vga_width + col;
+    tty_buffer[index] = blank;
+  }
+}
+
 void tty_putchar(char c) {
   if(c == '\n') {
     tty_row++;
     tty_column = 0;
 
     if (tty_row >= vga_height) {
-      tty_row = 0;
+      tty_scroll();
+      tty_row = vga_height - 1;
     }
   } else if(c == '\b') {
     if (tty_column > 0) {
@@ -52,7 +70,8 @@ void tty_putchar(char c) {
     if (++tty_column == vga_width) {
       tty_column = 0;
       if (++tty_row == vga_height) {
-        tty_row = 0;
+        tty_scroll();
+        tty_row = vga_height - 1;
       }
     }
   }
diff --git a/user/isodir/boot/kernel b/user/isodir/boot/kernel
Binary files differ.
diff --git a/vfs.c b/vfs.c
@@ -9,6 +9,9 @@ size_t vfs_read(unsigned int fd, void *buf, size_t size) {
 
     for (size_t i = 0; i < size; i++) {
       ptr[i] = keyboard_read();
+      if (ptr[i] == '\n') {
+        return EOF;
+      }
       bytes_read++;
     }
     return bytes_read;