Added logging module.

Makefile

@@ -73,7 +73,7 @@ qemu: iso
 		-drive if=pflash,format=raw,readonly=on,file=$(OVMF_CODE) \
 		-drive format=raw,file=$(ISO_FILE) \
 		-smp 4 -m 4G -cpu max -s -d unimp,guest_errors,int \
-		-monitor stdio \
+		-serial stdio \
 		-device qemu-xhci -device usb-kbd -audiodev pa,id=snd0 -machine pcspk-audiodev=snd0 -M q35 --no-reboot
 
 qemu-nographic: iso # yo stop allocating so much my pc only has 8G atleast allocate 2G

system/core/src/asm.rs

@@ -0,0 +1,17 @@
+mod asm {
+        pub fn outportb(port: u16, data: u8) {
+                core::arch::naked_asm!(
+                    asm("outb %1, %0" : : "dN" (port), "a" (data));
+                )
+            }
+
+        pub fn inportb(port: u16) {
+                core::arch::naked_asm!(
+                    u8 r;
+                    asm("inb %1, %0" : "=a" (r) : "dN" (port));
+                    return r;
+                )
+
+
+            }
+}

system/core/src/log.rs

@@ -0,0 +1,59 @@
+mod asm;
+use asm::{inportb, outportb};
+
+/*
+How to use:
+log::error(" filepath/file.rs: I don't like this variable "); --> [ERROR]  filepath/file.rs: I don't like this variable.
+log:warning(" filepath/file.rs: I'm so bad at rust."); --> [WARNING]  filepath/file.rs: I'm so bad at rust
+log::info(" filepath/file.rs: I'm so tired, stop with this.") --> [INFO]  filepath/file.rs: I'm so tired of this.
+*/
+
+mod log {
+  fn serial_ready() -> bool {
+    return inportb(0x3F8 + 5) & 0x20 != 0; // check 0x3F8 is able to write.
+  }
+
+  fn serial_write(c: char) {
+    while !serial_ready() {}
+    outportb(0x3F8, c as u8);
+  }
+
+  pub fn init() {
+    outportb(0x3F8 + 1, 0x00); // disable interrupts
+
+    outportb(0x3F8 + 3, 0x80);
+    outportb(0x3F8 + 0, 0x03);
+    outportb(0x3F8 + 1, 0x00);
+    outportb(0x3F8 + 3, 0x03);
+    outportb(0x3F8 + 2, 0xC7);
+
+    outportb(0x3F8 + 4, 0x0B);
+  }
+
+  pub fn print(msg: Option<&str>) {
+    if msg.is_none() { return; }
+
+    for c in msg.unwrap().chars() { // write all characters one by one.. TODO: Add formatting.
+          serial_write(c);
+    }
+
+    serial_write('\n');
+  }
+
+  pub fn error(msg: Option<&str>) {
+    if let Some(txt) = msg {
+      print(Some(&format!("\033[31m [ERROR] \033[0m {}", txt)));
+    }
+  }
+  pub fn warning(msg: Option<&str>) {
+    if let Some(txt) = msg {
+      print(Some(&format!("\033[95m [WARNING] \033[0m {}", txt)));
+    }
+  }
+
+  pub fn info(msg: Option<&str>) {
+    if let Some(txt) = msg {
+      print(Some(&format!("\033[96m [INFO] \033[0m {}", txt)));
+    }
+  }
+}