implement prover stdin reading

src/drivers/keyboard.c

@@ -1,5 +1,11 @@
 #include "../include/keyboard.h"
 #include <stdbool.h>
+#include "../include/task.h"
+#include "../include/string.h"
+
+char stdin_buffer[STDIN_BUFFER_SIZE];
+int stdin_pos = 0;
+bool stdin_has_line = false;
 
 unsigned char kbdus[128] =
 {
@@ -87,39 +93,60 @@ bool caps_pressed;
 
 void keyboard_wait();
 
-void handle_keyboard()
-{//3a
-	uint8_t scancode = inb(0x60);
+void handle_keyboard() {
+  uint8_t scancode = inb(0x60);
 
-	if(scancode & 0x80)//key released
-	{
-		scancode = scancode-0x80;
-		if(scancode == 0x2a || scancode == 0x36)
-			shift_pressed = false;
-		//printf("(%X)%c released ", scancode, kbdus[scancode-0x80]);
-	}
-	else//key pressed
-	{
-		if(scancode == 0x2a || scancode == 0x36)
-		{
-			shift_pressed = true;
-			return;
-		}
+  if (scancode & 0x80) {  // Released
+      scancode -= 0x80;
+      if (scancode == 0x2A || scancode == 0x36) shift_pressed = false;
+  } else {  // Pressed
+      if (scancode == 0x2A || scancode == 0x36) {
+          shift_pressed = true;
+          return;
+      }
+      if (scancode == 0x3A) {  // Caps
+          return;
+      }
 
-		if(scancode == 0x3a)
-		{
-			caps_pressed = !caps_pressed;
-			outb(0x60, 0xed);//set LED command
-			keyboard_wait();
-			outb(0x60, caps_pressed << 2);//0 is scroll lock, 1 is numlock, 2 is caps lock
-			return;
-		}
+      char c;
+      if (shift_pressed || caps_pressed) c = kbdus2[scancode];
+      else c = kbdus[scancode];
 
-		if(shift_pressed || caps_pressed)
-			printf("%c", kbdus2[scancode]);
-		else
-			printf("%c", kbdus[scancode]); //printf("(0x%X)%c", scancode, kbdus[scancode]);
-	}
+      if (c == '\b') {  //Backspace
+          if (stdin_pos > 0) {
+              stdin_pos--;
+              printf("\b \b");
+          }
+      } else if (c == '\n') {  // Enter
+          if (stdin_pos < STDIN_BUFFER_SIZE - 1) {
+              stdin_buffer[stdin_pos++] = '\n';
+              printf("\n");
+          }
+          stdin_has_line = true;
+
+          // Wake-up: wake up all Waiting tasks on STDIN
+          scheduler_lock();
+          Process *p = queue;
+          while (p) {
+              if (p->state == Waiting && p->waiting_reason == STDIN) {
+                  p->state = Ready;
+                  p->waiting_reason = NONE;
+              }
+              p = p->next;
+          }
+          scheduler_unlock();
+      } else if (c != 0 && stdin_pos < STDIN_BUFFER_SIZE - 1) {//if printable
+          stdin_buffer[stdin_pos++] = c;
+          printf("%c", c);//echo
+      }
+  }
+}
+
+void init_keyboard()
+{
+  memset(stdin_buffer, 0, STDIN_BUFFER_SIZE);
+  stdin_pos = 0;
+  stdin_has_line = false;
 }
 
 void keyboard_wait()