Fix basic QEMU port

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3357 42af7a65-404d-4744-a932-0658087f49c3

7 files changed, 103 insertions, 436 deletions

diff --git a/nuttx/arch/x86/src/i486/i486_utils.S b/nuttx/arch/x86/src/i486/i486_utils.S
index d94024f78..ee89c0c68 100644
--- a/nuttx/arch/x86/src/i486/i486_utils.S
+++ b/nuttx/arch/x86/src/i486/i486_utils.S
@@ -42,6 +42,8 @@
 
 #include <nuttx/config.h>
 
+	.file	"i486_utils.S"
+
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
@@ -49,73 +51,14 @@
  #define KSEG 0x10
 
 /****************************************************************************
- * Nasm
- ****************************************************************************/
-
-#ifdef CONFIG_X86_NASM
-
-/****************************************************************************
- * Nasm externals
- ****************************************************************************/
-
-global gdt_flush
-global idt_flush
-
-/****************************************************************************
- * Nasm macros
- ****************************************************************************/
-
-/****************************************************************************
- * Nasm .text
- ****************************************************************************/
-
-SECTION .text
-BITS 32
-
-/****************************************************************************
- * Name: gdt_flush
- ****************************************************************************/
-
-gdt_flush:
-    mov		eax, [esp+4]		/* Get the pointer to the GDT, passed as a parameter */
-    lgdt	[eax]				/* Load the new GDT pointer */
-
-    mov		$KSEG, ax 			/* KSEG is the offset in the GDT to our data segment */
-    mov		ax, ds				/* Load all data segment selectors */
-    mov		ax, es
-    mov		ax, fs
-    mov		ax, gs
-    mov		ax, ss
-    jmp		0x08:.gflush		/* 0x08 is the offset to our code segment: Far jump! */
-.gflush:
-    ret
-
-/****************************************************************************
- * Name: idt_flush
- ****************************************************************************/
-
-idt_flush:
-    mov		eax, [esp+4]		/* Get the pointer to the IDT, passed as a parameter */
-    lidt	[eax]				/* Load the IDT pointer */
-    ret
-
-#else /* !CONFIG_X86_NASM (GAS) */
-
-/****************************************************************************
- * GAS
- ****************************************************************************/
-
-	.file	"i486_utils.S"
-
-/****************************************************************************
- * GAS Globals
+ * Globals
  ****************************************************************************/
 
 	.globl	gdt_flush
 	.globl	idt_flush
 
 /****************************************************************************
- * GAS .text
+ * .text
  ****************************************************************************/
 
 	.text
@@ -151,4 +94,3 @@ idt_flush:
     ret
 	.size	idt_flush, . - idt_flush
 	.end
-#endif /* CONFIG_X86_NASM */
diff --git a/nuttx/arch/x86/src/qemu/qemu_fullcontextrestore.S b/nuttx/arch/x86/src/qemu/qemu_fullcontextrestore.S
index 6f15662dd..7d25e9072 100644
--- a/nuttx/arch/x86/src/qemu/qemu_fullcontextrestore.S
+++ b/nuttx/arch/x86/src/qemu/qemu_fullcontextrestore.S
@@ -45,34 +45,36 @@
 #include <arch/irq.h>
 #include "up_internal.h"
 
-/**************************************************************************
- * Pre-processor Definitions
- **************************************************************************/
-
-/**************************************************************************
- * Private Types
- **************************************************************************/
+	.file	"qemu_fullcontextrestore.S"
 
 /**************************************************************************
- * Private Function Prototypes
+ * Pre-processor Definitions
  **************************************************************************/
 
 /**************************************************************************
  * Global Variables
  **************************************************************************/
 
-/**************************************************************************
- * Private Variables
- **************************************************************************/
+/****************************************************************************
+ * Macros
+ ****************************************************************************/
 
-/**************************************************************************
- * Private Functions
- **************************************************************************/
+/* Trace macros, use like trace 'i' to print char to serial port. */
+
+	.macro	trace, ch
+#ifdef CONFIG_DEBUG
+	mov		$0x3f8, %dx
+	mov		$\ch, %al
+	out		%al, %dx
+#endif
+	.endm
 
 /**************************************************************************
  * Public Functions
  **************************************************************************/
 
+	.text
+
 /**************************************************************************
  * Name: up_fullcontextrestore
  *
@@ -81,11 +83,6 @@
  *
  **************************************************************************/
 
-#ifdef CONFIG_X86_NASM
-#  warning "No Nasm support"
-#else
-	.file	"qemu_fullcontextrestore.S"
-	.text
 	.globl	up_fullcontextrestore
 	.type	up_fullcontextrestore, @function
 up_fullcontextrestore:
@@ -105,38 +102,54 @@ up_fullcontextrestore:
 
 	movl	(4*REG_SP)(%eax), %esp
 
-	/* Save the return address, EFLAGS, and the values  as well the
-	 * values of EBX and EAC on the new stack.
+	/* Create an interrupt stack frame for the final iret.
+	 *
+	 * SP Before -> 
+	 *              SS
+	 *              ESP
+	 *              EFLAGS
+	 *              CS
+	 * SP After  -> EIP
 	 */
 
-	movl	(4*REG_EIP)(%eax), %ebx
+	mov		(4*REG_SS)(%eax), %ebx
+	push	%ebx
+	movl	(4*REG_SP)(%eax), %ebx
 	push	%ebx
 	movl	(4*REG_EFLAGS)(%eax), %ebx
 	push	%ebx
+	mov		(4*REG_CS)(%eax), %ebx
+	push	%ebx
+	movl	(4*REG_EIP)(%eax), %ebx
+	push	%ebx
+
+	/* Save the value of EAX on the stack too */
+
 	movl	(4*REG_EAX)(%eax), %ebx
 	push	%ebx
 
 	/* Now restore the remaining registers */
 
-	movl	(4*REG_EDI)(%eax), %edi
 	movl	(4*REG_ESI)(%eax), %esi
+	movl	(4*REG_EDI)(%eax), %edi
 	movl	(4*REG_EBP)(%eax), %ebp
+	movl	(4*REG_EBX)(%eax), %ebx
 	movl	(4*REG_EDX)(%eax), %edx
 	movl	(4*REG_ECX)(%eax), %ecx
-	movl	(4*REG_EBX)(%eax), %ebx
 
-	/* Restore the segment registers */
+	/* Restore the data segment register.  I think there is an issue that will
+	 * need to be address here at some time:  If the register save area is in
+	 * one data segment and the stack is in another, then the above would not
+	 * work (and, conversely, if they are in the same data segment, the
+	 * following is unnecessary and redundant).
+	 */
 
 	mov		(4*REG_DS)(%eax), %ds
-	mov		(4*REG_CS)(%eax), %cs
-	mov		(4*REG_SS)(%eax), %ss
 
-	/* Restore the correct value of EAX, EBX, and the EFLAGS then return */
+	/* Restore the correct value of EAX and then return */
 
 	popl	%eax
-	popf
-	ret
+	iret
 	.size up_fullcontextrestore, . - up_fullcontextrestore
     .end
-#endif /* CONFIG_X86_NASM */
 
diff --git a/nuttx/arch/x86/src/qemu/qemu_head.S b/nuttx/arch/x86/src/qemu/qemu_head.S
index 096705f46..9933d91ff 100755
--- a/nuttx/arch/x86/src/qemu/qemu_head.S
+++ b/nuttx/arch/x86/src/qemu/qemu_head.S
@@ -39,6 +39,8 @@
 

 #include <nuttx/config.h>

 

+	.file	"qemu_head.S"

+

 /****************************************************************************

  * Pre-processor definitions

  ****************************************************************************/

@@ -56,94 +58,35 @@
 #define HEAP_BASE	(STACKBASE+CONFIG_IDLETHREAD_STACKSIZE)

 

 /****************************************************************************

- * Nasm .text

+ * Macros

  ****************************************************************************/

 

-#ifdef CONFIG_X86_NASM

-global		__start						/* Making entry point visible to linker */

-global		g_heapbase					/* The start of the heap */

-extern		os_start					/* os_start is defined elsewhere */

-extern		up_lowsetup					/* up_lowsetup is defined elsewhere */

- 

-/* Setting up the Multiboot header - see GRUB docs for details */

-

-MODULEALIGN	equ	1<<0					/* Align loaded modules on page boundaries */

-MEMINFO		equ	1<<1					/* Provide memory map */

-FLAGS		equ	MODULEALIGN | MEMINFO	/* This is the Multiboot 'flag' field */

-MAGIC		equ	0x1badb002				/* 'magic number' lets bootloader find the header */

-CHECKSUM	equ -(MAGIC + FLAGS)		/* Checksum required */

- 

-section .text

-align 4

-MultiBootHeader:

-	dd		MAGIC

-	dd		FLAGS

-	dd		CHECKSUM

- 

-__start:

-	/* Set up the stack */

-

-	mov		esp, idle_stack + CONFIG_IDLETHREAD_STACKSIZE

-

-	/* Multiboot setup */

+/* Trace macros, use like trace 'i' to print char to serial port. */

 

-	push	eax							/* Pass Multiboot magic number */

-	push	ebx							/* Pass Multiboot info structure */

+	.macro	trace, ch

+#ifdef CONFIG_DEBUG

+	mov		$0x3f8, %dx

+	mov		$\ch, %al

+	out		%al, %dx

+#endif

+	.endm

 

-	/* Initialize and start NuttX */

-

-	call	up_lowsetup					/* Low-level, pre-OS initialization */

-	call	os_start					/* Start NuttX */

- 

-	/* NuttX will not return */

-

-	cli

-hang:

-	hlt									/* Halt machine should NuttX return */

-	jmp		hang

- 

 /****************************************************************************

- * .bss

+ * Global Symbols

  ****************************************************************************/

 

-/* The stack for the IDLE task thread is declared in .bss.  NuttX boots and

- * initializes on the IDLE thread, then at the completion of OS startup, this

- * thread becomes the thread that executes when there is nothing else to

- * do in the system (see up_idle()).

- */

-

-section .bss

-align 4

-idle_stack:

-	resb CONFIG_IDLETHREAD_STACKSIZE

+	.global	__start						/* Making entry point visible to linker */

+	.global	os_start					/* os_start is defined elsewhere */

+	.global	up_lowsetup					/* up_lowsetup is defined elsewhere */

+	.global	g_heapbase					/* The start of the heap */

 

 /****************************************************************************

- * .rodata

+ * .text

  ****************************************************************************/

-

-section .rodata

-

-/* HEAP BASE: _sbss is the start of the BSS region (see ld.script) _ebss is

- * the end of the BSS region (see ld.script). The heap continues from there

- * until the end of memory.

- */

-

-align 4

-g_heapbase:

-	dd	_ebss

-

-#else /* !CONFIG_X86_NASM (GAS) */

-

 /****************************************************************************

- * GAS .text

+ * Multiboot Header

  ****************************************************************************/

 

-	.file	"qemu_head.S"

-	.global	__start						/* Making entry point visible to linker */

-	.global	os_start					/* os_start is defined elsewhere */

-	.global	up_lowsetup					/* up_lowsetup is defined elsewhere */

-	.global	g_heapbase					/* The start of the heap */

-

 	/* Setting up the Multiboot header - see GRUB docs for details */

 

 	.set	ALIGN, 1<<0					/* Align loaded modules on page boundaries */

@@ -158,28 +101,24 @@ g_heapbase:
 	.long	FLAGS

 	.long	CHECKSUM

 

+/****************************************************************************

+ * Name: Start

+ ****************************************************************************/

+

 	.type	__start, @function

 __start:

 	/* Set up the stack */

-        mov     $'a', %ax

-        mov     $0x3f8, %dx

-        outb    %al, %dx

+

 	mov		$(idle_stack + CONFIG_IDLETHREAD_STACKSIZE), %esp

 

 	/* Multiboot setup */

 

 	push	%eax						/* Multiboot magic number */

 	push	%ebx						/* Multiboot data structure */

-        mov     $'b', %ax

-        mov     $0x3f8, %dx

-        outb    %al, %dx

 

 	/* Initialize and start NuttX */

 

 	call	up_lowsetup					/* Low-level, pre-OS initialization */

-        mov     $'c', %ax

-        mov     $0x3f8, %dx

-        outb    %al, %dx

 	call	os_start					/* Start NuttX */

 

 	/* NuttX will not return */

@@ -220,4 +159,3 @@ g_heapbase:
 	.long	_ebss

 	.size	g_heapbase, . - g_heapbase

 	.end

-#endif /* CONFIG_X86_NASM */

diff --git a/nuttx/arch/x86/src/qemu/qemu_irq.c b/nuttx/arch/x86/src/qemu/qemu_irq.c
index f266f6714..b92db7882 100755
--- a/nuttx/arch/x86/src/qemu/qemu_irq.c
+++ b/nuttx/arch/x86/src/qemu/qemu_irq.c
@@ -78,6 +78,8 @@ uint32_t *current_regs;
  * Private Data
  ****************************************************************************/
 
+static struct idt_entry_s idt_entries[256];
+
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
@@ -171,10 +173,7 @@ static void up_idtentry(struct idt_entry_s *entry, uint32_t base,
 
 static inline void up_idtinit(void)
 {
-  /* This uses a ton of stack! */
-
-  struct idt_entry_s idt_entries[256];
-  struct idt_ptr_s   idt_ptr;
+  struct idt_ptr_s idt_ptr;
 
   idt_ptr.limit = sizeof(struct idt_entry_s) * 256 - 1;
   idt_ptr.base  = (uint32_t)&idt_entries;
diff --git a/nuttx/arch/x86/src/qemu/qemu_lowsetup.c b/nuttx/arch/x86/src/qemu/qemu_lowsetup.c
index bbc7f1229..bc5aa52e7 100644
--- a/nuttx/arch/x86/src/qemu/qemu_lowsetup.c
+++ b/nuttx/arch/x86/src/qemu/qemu_lowsetup.c
@@ -52,6 +52,8 @@
  * Private Data
  ****************************************************************************/
 
+static struct gdt_entry_s gdt_entries[5];
+
 /****************************************************************************
  * Private Functions
  ****************************************************************************/
@@ -93,8 +95,7 @@ static void up_gdtentry(struct gdt_entry_s *entry, uint32_t base,
 
 static void up_gdtinit(void)
 {
-  struct gdt_entry_s gdt_entries[5];
-  struct gdt_ptr_s   gdt_ptr;
+  struct gdt_ptr_s gdt_ptr;
 
   up_gdtentry(&gdt_entries[0], 0, 0, 0, 0);                /* Null segment */
   up_gdtentry(&gdt_entries[1], 0, 0xffffffff, 0x9a, 0xcf); /* Code segment */
diff --git a/nuttx/arch/x86/src/qemu/qemu_saveusercontext.S b/nuttx/arch/x86/src/qemu/qemu_saveusercontext.S
index 4e38784a4..ffa1cf7f6 100644
--- a/nuttx/arch/x86/src/qemu/qemu_saveusercontext.S
+++ b/nuttx/arch/x86/src/qemu/qemu_saveusercontext.S
@@ -45,33 +45,31 @@
 #include <arch/irq.h>
 #include "up_internal.h"
 
-/**************************************************************************
- * Private Definitions
- **************************************************************************/
+	.file	"qemu_saveusercontext.S"
 
 /**************************************************************************
- * Private Types
+ * Pre-processor Definitions
  **************************************************************************/
 
-/**************************************************************************
- * Private Function Prototypes
- **************************************************************************/
+/****************************************************************************
+ * Macros
+ ****************************************************************************/
 
-/**************************************************************************
- * Global Variables
- **************************************************************************/
+/* Trace macros, use like trace 'i' to print char to serial port. */
 
-/**************************************************************************
- * Private Variables
- **************************************************************************/
+	.macro	trace, ch
+#ifdef CONFIG_DEBUG
+	mov		$0x3f8, %dx
+	mov		$\ch, %al
+	out		%al, %dx
+#endif
+	.endm
 
 /**************************************************************************
- * Private Functions
+ * .text
  **************************************************************************/
 
-/**************************************************************************
- * Public Functions
- **************************************************************************/
+	.text
 
 /**************************************************************************
  * Name: up_saveusercontext
@@ -95,11 +93,6 @@
  *
  **************************************************************************/
 
-#ifdef CONFIG_X86_NASM
-#  warning "No Nasm support"
-#else
-	.file	"qemu_saveusercontext.S"
-	.text
 	.globl	up_saveusercontext
 	.type	up_saveusercontext, @function
 up_saveusercontext:
@@ -151,4 +144,3 @@ up_saveusercontext:
 	ret
 	.size	up_saveusercontext, . - up_saveusercontext
     .end
-#endif
diff --git a/nuttx/arch/x86/src/qemu/qemu_vectors.S b/nuttx/arch/x86/src/qemu/qemu_vectors.S
index 068ce00c2..a512e1f95 100755
--- a/nuttx/arch/x86/src/qemu/qemu_vectors.S
+++ b/nuttx/arch/x86/src/qemu/qemu_vectors.S
@@ -1,5 +1,5 @@
 /****************************************************************************
- *  arch/x86/src/qemu/qemu_head.S
+ * arch/x86/src/qemu/qemu_head.S
  *
  *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
@@ -43,6 +43,8 @@
 #include <nuttx/config.h>
 #include <arch/irq.h>
 
+	.file	"qemu_vectors.S"
+
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
@@ -50,242 +52,20 @@
 #define KSEG 0x10
 
 /****************************************************************************
- * Nasm .text
- ****************************************************************************/
-
-#ifdef CONFIG_X86_NASM
-
-/****************************************************************************
- * Nasm externals
- ****************************************************************************/
-
-extern irq_handler
-extern isr_handler
-
-/****************************************************************************
- * Nasm macros
+ * .text
  ****************************************************************************/
 
-/* Trace macros, use like trace 'i' to print char to serial port. */
-
-%macro	io_outb 2
-	mov		dx, %1				/* param1 = address, param2 = data. */
-	mov		al, %2
-	out		dx, al
-%endmacro
-
-%macro  trace 1
-	io_outb	0x3f8, %1			/*  diagnostic character */
-%endmacro
-
-/* This macro creates a stub for an ISR which does NOT pass it's own
- * error code (adds a dummy errcode byte).
- */
-
-%macro ISR_NOERRCODE 1
-  global	vector_isr%1
-  vector_isr%1:
-	cli							/* Disable interrupts firstly. */
-	push	byte 0				/* Push a dummy error code. */
-	push	byte %1				/* Push the interrupt number. */
-	jmp		isr_common			/* Go to our common handler code. */
-%endmacro
-
-/* This macro creates a stub for an ISR which passes it's own
- * error code.
- */
-
-%macro ISR_ERRCODE 1
-  global	vector_isr%1
-  vector_isr%1:
-	cli							/* Disable interrupts. */
-	push	byte %1				/* Push the interrupt number */
-	jmp		isr_common
-%endmacro
-
-/* This macro creates a stub for an IRQ - the first parameter is
- * the IRQ number, the second is the ISR number it is remapped to.
- */
+	.text
 
-%macro IRQ 2
-  global	vector_irq%1
-  vector_irq%1:
-	cli
-	push	byte 0
-	push	byte %2
-	jmp		irq_common
-%endmacro
-		
 /****************************************************************************
- * Nasm vectors
- ****************************************************************************/
-
-/* The following will be the vector address programmed into the IDT */
-
-ISR_NOERRCODE		ISR0
-ISR_NOERRCODE		ISR1
-ISR_NOERRCODE		ISR2
-ISR_NOERRCODE		ISR3
-ISR_NOERRCODE		ISR4
-ISR_NOERRCODE		ISR5
-ISR_NOERRCODE		ISR6
-ISR_NOERRCODE		ISR7
-ISR_ERRCODE			ISR8
-ISR_NOERRCODE		ISR9
-ISR_ERRCODE			ISR10
-ISR_ERRCODE			ISR11
-ISR_ERRCODE			ISR12
-ISR_ERRCODE			ISR13
-ISR_ERRCODE			ISR14
-ISR_NOERRCODE		ISR15
-ISR_NOERRCODE		ISR16
-ISR_NOERRCODE		ISR17
-ISR_NOERRCODE		ISR18
-ISR_NOERRCODE		ISR19
-ISR_NOERRCODE		ISR20
-ISR_NOERRCODE		ISR21
-ISR_NOERRCODE		ISR22
-ISR_NOERRCODE		ISR23
-ISR_NOERRCODE		ISR24
-ISR_NOERRCODE		ISR25
-ISR_NOERRCODE		ISR26
-ISR_NOERRCODE		ISR27
-ISR_NOERRCODE		ISR28
-ISR_NOERRCODE		ISR29
-ISR_NOERRCODE		ISR30
-ISR_NOERRCODE		ISR31
-IRQ				 0,	IRQ0
-IRQ				 1,	IRQ1
-IRQ 			 2,	IRQ2
-IRQ				 3,	IRQ3
-IRQ				 4,	IRQ4
-IRQ				 5,	IRQ5
-IRQ				 6,	IRQ6
-IRQ				 7,	IRQ7
-IRQ				 8,	IRQ8
-IRQ				 9,	IRQ9
-IRQ				10,	IRQ10
-IRQ				11,	IRQ11
-IRQ				12,	IRQ12
-IRQ				13,	IRQ13
-IRQ				14,	IRQ14
-IRQ				15,	IRQ15
-
-/****************************************************************************
- * Name: isr_common
- *
- * Description:
- *   This is the common ISR logic. It saves the processor state, sets up for
- *   kernel mode segments, calls the C-level fault handler, and finally
- *   restores the stack frame.
- *
- ****************************************************************************/
-
-isr_common:
-/*	trace	'S' */
-	pusha						/* Pushes edi,esi,ebp,esp,ebx,edx,ecx,eax */
-
-	mov		ax, ds				/* Lower 16-bits of eax = ds. */
-	push	eax					/* Save the data segment descriptor */
-
-	mov		ax, KSEG			/* Load the kernel data segment descriptor */
-	mov		ds, ax
-	mov		es, ax
-	mov		fs, ax
-	mov		gs, ax
-
-	/* The current value of the SP points to the beginning of the state save
-	 * structure.  Save that on the stack as the input parameter to isr_handler.
-	 */
-
-	mov		esp, eax
-	push	eax
-	call	isr_handler
-	jmp		.Lreturn
-
-/****************************************************************************
- * Name: irq_common
- *
- * Description:
- *   This is the common IRQ logic. It saves the processor state, sets up for
- *   kernel mode segments, calls the C-level fault handler, and finally
- *   restores the stack frame.
- *
- ****************************************************************************/
-
-irq_common:
-/*	trace	'R' */
-	pusha						/* Pushes edi,esi,ebp,esp,ebx,edx,ecx,eax */
-
-	mov		ax, ds				/* Lower 16-bits of eax = ds. */
-	push	eax					/* Save the data segment descriptor */
-
-	mov		ax, KSEG			/* Load the kernel data segment descriptor */
-	mov		ds, ax
-	mov		es, ax
-	mov		fs, ax
-	mov		gs, ax
-
-	/* The current value of the SP points to the beginning of the state save
-	 * structure.  Save that on the stack as the input parameter to irq_handler.
-	 */
-
-	mov		esp, eax
-	push	eax
-	call	irq_handler
-
-	/* The common return point for both isr_handler and irq_handler */
-
-.Lreturn:
-	add		4, esp
-
-	/* EAX may possibly hold a pointer to a different regiser save area on
-	 * return.  Are we switching to a new context?
-	 */
-
-	cmp		eax, esp
-	je		.Lnoswitch
-
-	/* A context swith will be performed. EAX holds the address of the new
-	 * register save structure.
-	 *
-	 * 'Jump' to up_fullcontextrestore().  We perform a call here, but that function
-	 * never returns.  The address of the new register save block is the argument
-	 * to the up_fullcontextrestore().
-	 */
-
-	push	eax
-	jmp		up_fullcontext
-
-.Lnoswitch:
-	pop		ebx					/* Reload the original data segment descriptor */
-	mov		ds, bx
-	mov		es, bx
-	mov		fs, bx
-	mov		gs, bx
-
-	popa						/* Pops edi,esi,ebp... */
-	add		esp, 8				/* Cleans up the pushed error code and pushed ISR number */
-	sti
-	iret						/* Pops 5 things at once: CS, EIP, EFLAGS, SS, and ESP */
-
-#else /* !CONFIG_X86_NASM (GAS) */
-
-/****************************************************************************
- * GAS .text
- ****************************************************************************/
-
-	.file	"qemu_vectors.S"
-
-/****************************************************************************
- * GAS globals
+ * Globals
  ****************************************************************************/
 
 	.globl	irq_handler
 	.globl	isr_handler
 
 /****************************************************************************
- * GAS macros
+ * Macros
  ****************************************************************************/
 
 /* Trace macros, use like trace 'i' to print char to serial port. */
@@ -334,7 +114,10 @@ vector_irq\irqno:
 	jmp		isr_common			/* Go to the common handler code. */
 	.endm
 
-	/* The following will be the vector address programmed into the IDT */
+/****************************************************************************
+ * IDT Vectors
+ ****************************************************************************/
+/* The following will be the vector addresses programmed into the IDT */
 
 	ISR_NOERRCODE		ISR0
 	ISR_NOERRCODE		ISR1
@@ -487,4 +270,3 @@ irq_common:
 	iret						/* Pops 5 things at once: CS, EIP, EFLAGS, SS, and ESP */
 	.size	irq_common, . - irq_common
 	.end
-#endif /* CONFIG_X86_NASM */