Linux0.11使用串口进行输入输出

在使用qemu时我们将Linux0.11修改为使用串口作为标准输入输出，从而在文本模式下进行学习调试，补丁如下

diff --git a/Makefile b/Makefile
index 3ca10f3..d418782 100644
--- a/Makefile
+++ b/Makefile
@@ -80,8 +80,10 @@ clean:
     $(Q)rm -f kernel.elf boot/*.o  typescript* info bochsout.txt
     $(Q)for i in init mm fs kernel lib boot; do (cd $$i; make $(S) clean); done
 
-#QEMU_OPS:= -nographic -serial mon:stdio -m 64M -boot a
-QEMU_OPS:= -m 64M -boot a
+run: qemu
+
+QEMU_OPS:= -nographic -serial mon:stdio -m 64M -boot a
+#QEMU_OPS:= -m 64M -boot a
 qemu:
     qemu-system-i386 ${QEMU_OPS} -fda Image  -hda ./rootfs/hdc-0.11.img 
 
diff --git a/init/main.c b/init/main.c
index cd0b564..ce6b355 100644
--- a/init/main.c
+++ b/init/main.c
@@ -264,7 +264,7 @@ void init(void)
     int pid,i;
 
     setup((void *) &drive_info);
-    (void) open("/dev/tty0",O_RDWR,0);
+    (void) open("/dev/tty1",O_RDWR,0);
     (void) dup(0);
     (void) dup(0);
     printf("init current pid is %d\n", getpid());
@@ -295,7 +295,7 @@ void init(void)
             printf("while1 fork current pid is %d\n", getpid());
             close(0);close(1);close(2);
             setsid();
-            (void) open("/dev/tty0",O_RDWR,0);
+            (void) open("/dev/tty1",O_RDWR,0);
             (void) dup(0);
             (void) dup(0);
             _exit(execve("/bin/sh",argv,envp));
diff --git a/kernel/chr_drv/kb.S b/kernel/chr_drv/kb.S
index ffd28cf..ec476b3 100644
--- a/kernel/chr_drv/kb.S
+++ b/kernel/chr_drv/kb.S
@@ -65,7 +65,7 @@ e0_e1:    inb $0x61,%al
     outb %al,$0x61
     movb $0x20,%al
     outb %al,$0x20
-    pushl $0
+    pushl $1
     call do_tty_interrupt
     addl $4,%esp
     pop %es
diff --git a/kernel/chr_drv/tty_io.c b/kernel/chr_drv/tty_io.c
index ed14fa8..6d3a927 100644
--- a/kernel/chr_drv/tty_io.c
+++ b/kernel/chr_drv/tty_io.c
@@ -66,7 +66,7 @@ struct tty_struct tty_table[] = {
         {0, /* no translation */
         0,  /* no translation */
         B2400 | CS8,
-        0,
+        ECHO,
         0,
         INIT_C_CC},
         0,
@@ -79,7 +79,7 @@ struct tty_struct tty_table[] = {
         {0, /* no translation */
         0,  /* no translation */
         B2400 | CS8,
-        0,
+        ECHO,
         0,
         INIT_C_CC},
         0,
diff --git a/kernel/printk.c b/kernel/printk.c
index fe84b2b..6e3e65b 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -45,7 +45,7 @@ int printk(const char *fmt, ...)
         "pop %%fs\n\t"
         "pushl %0\n\t"
         "pushl $buf\n\t"
-        "pushl $0\n\t"
+        "pushl $1\n\t"
         "call tty_write\n\t"
         "addl $8,%%esp\n\t"
         "popl %0\n\t"