From 00869bcdc120d5975fa45c6e1ba349bb7a4c85c8 Mon Sep 17 00:00:00 2001
From: Jonas 'Sortie' Termansen <sortie@maxsi.org>
Date: Mon, 30 Apr 2012 17:23:43 +0200
Subject: [PATCH] The PIC can now be deprogrammed and reprogrammed.

---
 sortix/interrupt.cpp | 45 ++++++++++++++++++++++++++++++++------------
 sortix/time.cpp      |  6 +++---
 2 files changed, 36 insertions(+), 15 deletions(-)

diff --git a/sortix/interrupt.cpp b/sortix/interrupt.cpp
index 00a419ac..3bb01d81 100644
--- a/sortix/interrupt.cpp
+++ b/sortix/interrupt.cpp
@@ -87,6 +87,38 @@ const unsigned NUM_INTERRUPTS = 256UL;
 Handler interrupthandlers[NUM_INTERRUPTS];
 void* interrupthandlerptr[NUM_INTERRUPTS];
 
+extern "C" void ReprogramPIC()
+{
+	uint8_t mastermask = 0;
+	uint8_t slavemask = 0;
+	CPU::OutPortB(PIC_MASTER + PIC_COMMAND, PIC_CMD_INIT | PIC_ICW1_ICW4);
+	CPU::OutPortB(PIC_SLAVE + PIC_COMMAND, PIC_CMD_INIT | PIC_ICW1_ICW4);
+	CPU::OutPortB(PIC_MASTER + PIC_DATA, IRQ0);
+	CPU::OutPortB(PIC_SLAVE + PIC_DATA, IRQ8);
+	CPU::OutPortB(PIC_MASTER + PIC_DATA, 0x04); // Slave PIC at IRQ2
+	CPU::OutPortB(PIC_SLAVE + PIC_DATA, 0x02); // Cascade Identity
+	CPU::OutPortB(PIC_MASTER + PIC_DATA, PIC_MODE_8086);
+	CPU::OutPortB(PIC_SLAVE + PIC_DATA, PIC_MODE_8086);
+	CPU::OutPortB(PIC_MASTER + PIC_DATA, mastermask);
+	CPU::OutPortB(PIC_SLAVE + PIC_DATA, slavemask);
+}
+
+extern "C" void DeprogramPIC()
+{
+	uint8_t mastermask = 0;
+	uint8_t slavemask = 0;
+	CPU::OutPortB(PIC_MASTER + PIC_COMMAND, PIC_CMD_INIT | PIC_ICW1_ICW4);
+	CPU::OutPortB(PIC_SLAVE + PIC_COMMAND, PIC_CMD_INIT | PIC_ICW1_ICW4);
+	CPU::OutPortB(PIC_MASTER + PIC_DATA, 0x08);
+	CPU::OutPortB(PIC_SLAVE + PIC_DATA, 0x70);
+	CPU::OutPortB(PIC_MASTER + PIC_DATA, 0x04); // Slave PIC at IRQ2
+	CPU::OutPortB(PIC_SLAVE + PIC_DATA, 0x02); // Cascade Identity
+	CPU::OutPortB(PIC_MASTER + PIC_DATA, PIC_MODE_8086);
+	CPU::OutPortB(PIC_SLAVE + PIC_DATA, PIC_MODE_8086);
+	CPU::OutPortB(PIC_MASTER + PIC_DATA, mastermask);
+	CPU::OutPortB(PIC_SLAVE + PIC_DATA, slavemask);
+}
+
 void Init()
 {
 	initialized = false;
@@ -100,18 +132,7 @@ void Init()
 	}
 
 	// Remap the IRQ table on the PICs.
-	uint8_t mastermask = 0;
-	uint8_t slavemask = 0;
-	CPU::OutPortB(PIC_MASTER + PIC_COMMAND, PIC_CMD_INIT | PIC_ICW1_ICW4);
-	CPU::OutPortB(PIC_SLAVE + PIC_COMMAND, PIC_CMD_INIT | PIC_ICW1_ICW4);
-	CPU::OutPortB(PIC_MASTER + PIC_DATA, IRQ0);
-	CPU::OutPortB(PIC_SLAVE + PIC_DATA, IRQ8);
-	CPU::OutPortB(PIC_MASTER + PIC_DATA, 0x04); // Slave PIC at IRQ2
-	CPU::OutPortB(PIC_SLAVE + PIC_DATA, 0x02); // Cascade Identity
-	CPU::OutPortB(PIC_MASTER + PIC_DATA, PIC_MODE_8086);
-	CPU::OutPortB(PIC_SLAVE + PIC_DATA, PIC_MODE_8086);
-	CPU::OutPortB(PIC_MASTER + PIC_DATA, mastermask);
-	CPU::OutPortB(PIC_SLAVE + PIC_DATA, slavemask);
+	ReprogramPIC();
 
 	RegisterRawHandler(0, isr0, false);
 	RegisterRawHandler(1, isr1, false);
diff --git a/sortix/time.cpp b/sortix/time.cpp
index cd4c86e5..15707af6 100644
--- a/sortix/time.cpp
+++ b/sortix/time.cpp
@@ -54,7 +54,7 @@ namespace Sortix
 			return microsecondssinceboot;
 		}
 
-		void RequestIQR0()
+		extern "C" void RequestIRQ0()
 		{
 			// The value we send to the PIT is the value to divide it's input clock
 			// (1193180 Hz) by, to get our required frequency. Important to note is
@@ -95,7 +95,7 @@ namespace Sortix
 
 			didUglyIRQ0Hack = false;
 
-			RequestIQR0();
+			RequestIRQ0();
 		}
 
 		void OnIRQ0(CPU::InterruptRegisters* Regs, void* /*user*/)
@@ -114,7 +114,7 @@ namespace Sortix
 			// TODO: There is a horrible bug that causes Sortix to only receive
 			// one IRQ0 on my laptop, but it works in virtual machines. But
 			// re-requesting an addtional time seems to work. Hacky and ugly.
-			if ( !didUglyIRQ0Hack ) { RequestIQR0(); didUglyIRQ0Hack = true; }
+			if ( !didUglyIRQ0Hack ) { RequestIRQ0(); didUglyIRQ0Hack = true; }
 		}
 
 		// TODO: Implement all the other useful functions regarding time.