From c055a2f6a9778f93a8f09b6d820d2504d3fa2601 Mon Sep 17 00:00:00 2001
From: Benji Dial <Benji3.141@gmail.com>
Date: Thu, 26 Dec 2019 18:21:44 -0500
Subject: keyboard skeleton, skeleton, rcs, etc

---
 src/kernel/serial.asm | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

(limited to 'src/kernel/serial.asm')

diff --git a/src/kernel/serial.asm b/src/kernel/serial.asm
index 6318bc5..2213fd8 100644
--- a/src/kernel/serial.asm
+++ b/src/kernel/serial.asm
@@ -17,7 +17,9 @@
 
 global send_byte
 global read_byte
+global poll_port
 
+section .text
 send_byte:;void send_byte(uint8_t value, uint8_t port)
   push ebp
   mov ebp, esp
@@ -77,5 +79,29 @@ read_byte:;uint8_t read_byte(uint8_t port)
   leave
   ret
 
+poll_port:;bool poll_port(uint8_t port)
+  push ebp
+  mov ebp, esp
+
+  xor eax, eax
+
+  xor ecx, ecx
+  mov cl, byte [ebp + 8];port
+
+  test cl, 0xfc
+  jnz .leave
+
+  shl cl, 1
+  mov dx, word [ecx + com_ports]
+
+  or dx, 5
+
+  in al, dx
+  and al, 0x01
+
+.leave:
+  leave
+  ret
+
 section .rodata
 com_ports dw 0x03f8, 0x02f8, 0x03e8, 0x02e8
\ No newline at end of file
-- 
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