From 61d6b06696b7efc6e6bc1df6573ba58e743d6ae3 Mon Sep 17 00:00:00 2001
From: Kevin O'Connor <kevin@koconnor.net>
Date: Sat, 21 Jun 2008 12:15:10 -0400
Subject: Init serial port before using it for debug - also reinit after option
 rom.

Apparently, some VGA option roms will enable serial irqs - this could
    cause problems with spurious irqs from debug messages.
Also, improve debugging of option roms that fail the checksum check.
---
 src/output.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

(limited to 'src/output.c')

diff --git a/src/output.c b/src/output.c
index 054082f..dd647a2 100644
--- a/src/output.c
+++ b/src/output.c
@@ -13,6 +13,25 @@
 #define DEBUG_PORT 0x03f8
 #define DEBUG_TIMEOUT 100000
 
+void
+debug_serial_setup()
+{
+    if (!CONFIG_DEBUG_SERIAL)
+        return;
+    // setup for serial logging: 8N1
+    u8 oldparam, newparam = 0x03;
+    oldparam = inb(DEBUG_PORT+3);
+    outb(newparam, DEBUG_PORT+3);
+    // Disable irqs
+    u8 oldier, newier = 0;
+    oldier = inb(DEBUG_PORT+1);
+    outb(newier, DEBUG_PORT+1);
+
+    if (oldparam != newparam || oldier != newier)
+        dprintf(1, "Changing serial settings was %x/%x now %x/%x\n"
+                , oldparam, oldier, newparam, newier);
+}
+
 static void
 debug_serial(char c)
 {
-- 
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