[Voyageurs] Add a basic ps/2 keyboard driver.

sys/voyageurs/keyboard/keyboard_driver.cpp

@@ -0,0 +1,34 @@
+#include "keyboard/keyboard_driver.h"
+
+#include <mammoth/util/debug.h>
+
+void InterruptEnter(void* void_keyboard) {
+  KeyboardDriver* keyboard = static_cast<KeyboardDriver*>(void_keyboard);
+
+  keyboard->InterruptLoop();
+}
+
+KeyboardDriver::KeyboardDriver() { check(ZIrqRegister(kZIrqKbd, &irq_cap_)); }
+
+void KeyboardDriver::RegisterListener(uint64_t port_cap) {
+  listeners_.PushFront(mmth::PortClient::AdoptPort(port_cap));
+}
+
+Thread KeyboardDriver::StartInterruptLoop() {
+  return Thread(InterruptEnter, this);
+}
+
+void KeyboardDriver::InterruptLoop() {
+  dbgln("Interrupt");
+  while (true) {
+    uint8_t scancode;
+    uint64_t num_bytes = 1;
+    uint64_t num_caps = 0;
+    check(ZPortRecv(irq_cap_, &num_bytes, &scancode, &num_caps, nullptr));
+    dbgln("Scan {x}", scancode);
+
+    for (mmth::PortClient& client : listeners_) {
+      client.WriteByte(scancode);
+    }
+  }
+}