From 872e6f33928d9247bf9901a624611fb6f36190bf Mon Sep 17 00:00:00 2001
From: Drew Galbraith <dgalbraith33@gmail.com>
Date: Wed, 17 May 2023 20:42:59 -0700
Subject: [PATCH] Add a debug output utility.

---
 zion/CMakeLists.txt  |  6 ++++++
 zion/debug/debug.cpp | 13 +++++++++++++
 zion/debug/debug.h   |  3 +++
 zion/zion.cpp        |  6 ++----
 4 files changed, 24 insertions(+), 4 deletions(-)
 create mode 100644 zion/debug/debug.cpp
 create mode 100644 zion/debug/debug.h

diff --git a/zion/CMakeLists.txt b/zion/CMakeLists.txt
index 45734b4..eb74bc5 100644
--- a/zion/CMakeLists.txt
+++ b/zion/CMakeLists.txt
@@ -1,6 +1,12 @@
 add_executable(zion
+  debug/debug.cpp
   zion.cpp)
 
+target_include_directories(zion
+  PRIVATE
+  ${CMAKE_CURRENT_SOURCE_DIR}
+  )
+
 # -c -- Don't run the linker.
 # -nostdlib -- Don't include the standard library.
 # -mabi=sysv -- Explicitly specify the ABI since we will rely on it.
diff --git a/zion/debug/debug.cpp b/zion/debug/debug.cpp
new file mode 100644
index 0000000..856765e
--- /dev/null
+++ b/zion/debug/debug.cpp
@@ -0,0 +1,13 @@
+#include "debug/debug.h"
+
+#include "common/port.h"
+
+#define COM1 0x3f8
+
+void dbgln(const char* str) {
+  while (*str != 0) {
+    outb(COM1, *str);
+    str++;
+  }
+  outb(COM1, '\n');
+}
diff --git a/zion/debug/debug.h b/zion/debug/debug.h
new file mode 100644
index 0000000..634a3b7
--- /dev/null
+++ b/zion/debug/debug.h
@@ -0,0 +1,3 @@
+#pragma once
+
+void dbgln(const char *str);
diff --git a/zion/zion.cpp b/zion/zion.cpp
index 8e59f54..c4d5aab 100644
--- a/zion/zion.cpp
+++ b/zion/zion.cpp
@@ -1,11 +1,9 @@
 #include <stdint.h>
 
-#include "common/port.h"
-
-#define COM1 0x3f8
+#include "debug/debug.h"
 
 extern "C" void zion() {
-  outb(COM1, 'a');
+  dbgln("Hello World!");
 
   while (1)
     ;