From eb934b266052965b9c480d11d6866a994f30731b Mon Sep 17 00:00:00 2001
From: John Hodge <tpg@prelude.mutabah.net>
Date: Wed, 21 Apr 2010 21:11:03 +0800
Subject: [PATCH] Added kernel panic routines to output to the screen on kpanic

---
 Kernel/arch/x86/Makefile  |  2 +-
 Kernel/arch/x86/errors.c  |  1 +
 Kernel/arch/x86/kpanic.c  | 55 +++++++++++++++++++++++++++++++++++++++
 Kernel/arch/x86/mm_virt.c |  2 ++
 Kernel/debug.c            | 29 ++++++++++++++++-----
 Kernel/include/acess.h    | 11 ++++----
 6 files changed, 88 insertions(+), 12 deletions(-)
 create mode 100644 Kernel/arch/x86/kpanic.c

diff --git a/Kernel/arch/x86/Makefile b/Kernel/arch/x86/Makefile
index 708c8dc1..c52e369b 100644
--- a/Kernel/arch/x86/Makefile
+++ b/Kernel/arch/x86/Makefile
@@ -32,4 +32,4 @@ endif
 A_OBJ  = start.ao main.o lib.o desctab.ao errors.o irq.o
 A_OBJ += mm_phys.o mm_virt.o
 A_OBJ += proc.o time.o vm8086.o
-#A_OBJ += gdb_stub.o
+A_OBJ += kpanic.o
diff --git a/Kernel/arch/x86/errors.c b/Kernel/arch/x86/errors.c
index 31c385fc..f5391832 100644
--- a/Kernel/arch/x86/errors.c
+++ b/Kernel/arch/x86/errors.c
@@ -66,6 +66,7 @@ void ErrorHandler(tRegs *Regs)
 		return ;
 	}
 	
+	Debug_KernelPanic();
 	Warning("CPU Error %i - %s, Code: 0x%x",
 		Regs->int_num, csaERROR_NAMES[Regs->int_num], Regs->err_code);
 	Warning(" CS:EIP = 0x%04x:%08x", Regs->cs, Regs->eip);
diff --git a/Kernel/arch/x86/kpanic.c b/Kernel/arch/x86/kpanic.c
new file mode 100644
index 00000000..505f698a
--- /dev/null
+++ b/Kernel/arch/x86/kpanic.c
@@ -0,0 +1,55 @@
+/*
+ * Acess 2 Kernel
+ * By John Hodge (thePowersGang)
+ * - x86 Kernel Panic Handler
+ */
+
+#include <acess.h>
+
+#define	FB	((Uint16 *)(KERNEL_BASE|0xB8000))
+
+ int	giKP_Pos = 0;
+
+/**
+ * \brief Sets the screen mode for a kernel panic
+ */
+void KernelPanic_SetMode()
+{
+	 int	i;
+	// Restore VGA 0xB8000 text mode
+	
+	// Clear Screen
+	for( i = 0; i < 80*25; i++ )
+	{
+		FB[i] = 0x4F00;
+	}
+}
+
+void KernelPanic_PutChar(char Ch)
+{
+	if( giKP_Pos > 80*25 )	return ;
+	switch(Ch)
+	{
+	case '\t':
+		do {
+			FB[giKP_Pos] &= 0xFF00;
+			FB[giKP_Pos++] |= ' ';
+		} while(giKP_Pos & 7);
+		break;
+	
+	case '\n':
+		giKP_Pos += 80;
+	case '\r':
+		giKP_Pos -= giKP_Pos % 80;
+		break;
+	
+	default:
+		if(' ' <= Ch && Ch < 0x7F)
+		{
+			FB[giKP_Pos] &= 0xFF00;
+			FB[giKP_Pos] |= Ch;
+		}
+		giKP_Pos ++;
+		break;
+	}
+}
diff --git a/Kernel/arch/x86/mm_virt.c b/Kernel/arch/x86/mm_virt.c
index cf77b875..db89cc14 100644
--- a/Kernel/arch/x86/mm_virt.c
+++ b/Kernel/arch/x86/mm_virt.c
@@ -214,6 +214,8 @@ void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
 		return ;
 	}
 	
+	Debug_KernelPanic();
+	
 	// -- Check Error Code --
 	if(ErrorCode & 8)
 		Warning("Reserved Bits Trashed!");
diff --git a/Kernel/debug.c b/Kernel/debug.c
index e8e181d5..ac9d6179 100644
--- a/Kernel/debug.c
+++ b/Kernel/debug.c
@@ -11,13 +11,16 @@
 #define	GDB_SERIAL_PORT	0x2F8
 
 // === IMPORTS ===
-extern void Threads_Dump();
+extern void Threads_Dump(void);
+extern void	KernelPanic_SetMode(void);
+extern void	KernelPanic_PutChar(char Ch);
 
 // === GLOBALS ===
  int	gDebug_Level = 0;
  int	giDebug_KTerm = -1;
  int	gbDebug_SerialSetup = 0;
  int	gbGDB_SerialSetup = 0;
+ int	gbDebug_IsKPanic = 0;
 
 // === CODE ===
 int putDebugChar(char ch)
@@ -75,11 +78,16 @@ static void Debug_Putchar(char ch)
 	outb(SERIAL_PORT, ch);
 	#endif
 	
-	if(gbInPutChar)	return ;
-	gbInPutChar = 1;
-	if(giDebug_KTerm != -1)
-		VFS_Write(giDebug_KTerm, 1, &ch);
-	gbInPutChar = 0;
+	if( !gbDebug_IsKPanic )
+	{
+		if(gbInPutChar)	return ;
+		gbInPutChar = 1;
+		if(giDebug_KTerm != -1)
+			VFS_Write(giDebug_KTerm, 1, &ch);
+		gbInPutChar = 0;
+	}
+	else
+		KernelPanic_PutChar(ch);
 }
 
 static void Debug_Puts(char *Str)
@@ -224,6 +232,12 @@ void Debug_Fmt(const char *format, va_list *args)
     }
 }
 
+void Debug_KernelPanic()
+{
+	gbDebug_IsKPanic = 1;
+	KernelPanic_SetMode();
+}
+
 /**
  * \fn void LogF(char *Msg, ...)
  */
@@ -262,6 +276,9 @@ void Warning(char *Fmt, ...)
 void Panic(char *Fmt, ...)
 {
 	va_list	args;
+	
+	Debug_KernelPanic();
+	
 	Debug_Puts("Panic: ");
 	va_start(args, Fmt);
 	Debug_Fmt(Fmt, &args);
diff --git a/Kernel/include/acess.h b/Kernel/include/acess.h
index db2dd964..09c4f517 100644
--- a/Kernel/include/acess.h
+++ b/Kernel/include/acess.h
@@ -115,11 +115,12 @@ extern void	Log_Debug(char *Ident, char *Message, ...);
  * \name Debugging and Errors
  * \{
  */
-extern void	Panic(char *Msg, ...);
-extern void	Warning(char *Msg, ...);
-extern void	Log(char *Fmt, ...);
-extern void	LogV(char *Fmt, va_list Args);
-extern void	LogF(char *Fmt, ...);
+extern void	Debug_KernelPanic();	//!< Initiate a kernel panic
+extern void	Panic(char *Msg, ...);	//!< Print a panic message (initiates a kernel panic)
+extern void	Warning(char *Msg, ...);	//!< Print a warning message
+extern void	LogF(char *Fmt, ...);	//!< Print a log message without a trailing newline
+extern void	Log(char *Fmt, ...);	//!< Print a log message
+extern void	LogV(char *Fmt, va_list Args);	//!< va_list Log message
 extern void	Debug_Enter(char *FuncName, char *ArgTypes, ...);
 extern void	Debug_Log(char *FuncName, char *Fmt, ...);
 extern void	Debug_Leave(char *FuncName, char RetType, ...);
-- 
2.20.1