kernel: Implement reading from /dev/console

kernel/src/arch/x86_64/CPU.cpp

@@ -4,9 +4,11 @@
 #include "arch/Timer.h"
 #include "arch/x86_64/CPU.h"
 #include "arch/x86_64/IO.h"
+#include "fs/devices/ConsoleDevice.h"
 #include "memory/MemoryManager.h"
 #include "sys/Syscall.h"
 #include "thread/Scheduler.h"
+#include "video/TextConsole.h"
 #include <cpuid.h>
 #include <luna/CString.h>
 #include <luna/CircularQueue.h>
@@ -124,7 +126,11 @@ void io_thread()
         while (!scancode_queue.try_pop(scancode)) { kernel_sleep(10); }
 
         char key;
-        if (Keyboard::decode_scancode(scancode).try_set_value(key)) { kdbgln("Read key: %c", key); }
+        if (Keyboard::decode_scancode(scancode).try_set_value(key))
+        {
+            TextConsole::putchar(key);
+            ConsoleDevice::did_press_key(key);
+        }
     }
 }
 

kernel/src/fs/devices/ConsoleDevice.cpp

@@ -1,15 +1,26 @@
 #include "fs/devices/ConsoleDevice.h"
 #include "video/TextConsole.h"
+#include <luna/Buffer.h>
+#include <luna/CString.h>
+
+static Buffer g_console_input;
 
 Result<SharedPtr<Device>> ConsoleDevice::create()
 {
     return (SharedPtr<Device>)TRY(make_shared<ConsoleDevice>());
 }
 
-// FIXME: Read from the keyboard.
-Result<usize> ConsoleDevice::read(u8*, usize, usize) const
+Result<usize> ConsoleDevice::read(u8* buf, usize, usize length) const
 {
-    return 0;
+    if (length > g_console_input.size()) length = g_console_input.size();
+
+    memcpy(buf, g_console_input.data(), length);
+
+    memmove(g_console_input.data(), g_console_input.data() + length, g_console_input.size() - length);
+
+    g_console_input.try_resize(g_console_input.size() - length).release_value();
+
+    return length;
 }
 
 Result<usize> ConsoleDevice::write(const u8* buf, usize, usize length)
@@ -20,5 +31,10 @@ Result<usize> ConsoleDevice::write(const u8* buf, usize, usize length)
 
 bool ConsoleDevice::blocking() const
 {
-    return false;
+    return g_console_input.size() == 0;
+}
+
+void ConsoleDevice::did_press_key(char key)
+{
+    *g_console_input.slice_at_end(1).value() = (u8)key;
 }

kernel/src/fs/devices/ConsoleDevice.h

@@ -11,6 +11,8 @@ class ConsoleDevice : public Device
 
     Result<usize> write(const u8*, usize, usize) override;
 
+    static void did_press_key(char key);
+
     bool blocking() const override;
 
     virtual ~ConsoleDevice() = default;