From 43d976edd03df9321e528624ba61c40bca64a87c Mon Sep 17 00:00:00 2001
From: Michael Brown <mcb30@etherboot.org>
Date: Wed, 20 Dec 2006 20:28:20 +0000
Subject: [PATCH] Prevent NULL from ever pointing to some real code or data. 
 (This was causing the serial console to ignore input, because it happened to
 end up linked with serial_ischar() at address 0, which core/console.c decided
 was invalid).

---
 src/arch/i386/scripts/i386-kir.lds | 4 ++++
 src/arch/i386/scripts/i386.lds     | 6 ++++++
 2 files changed, 10 insertions(+)

diff --git a/src/arch/i386/scripts/i386-kir.lds b/src/arch/i386/scripts/i386-kir.lds
index 3095b311..401298c9 100644
--- a/src/arch/i386/scripts/i386-kir.lds
+++ b/src/arch/i386/scripts/i386-kir.lds
@@ -64,6 +64,8 @@ SECTIONS {
     . = _text16_link_addr;
     _text16 = .;
 
+    . += 1;			/* Prevent NULL being valid */
+
     .text16 : AT ( _text16_load_offset + __text16 ) {
 	__text16 = .;
 	*(.text.null_trap)
@@ -80,6 +82,8 @@ SECTIONS {
     . = _data16_link_addr;
     _data16 = .;
 
+    . += 1;			/* Prevent NULL being valid */
+
     .rodata16 : AT ( _data16_load_offset + __rodata16 ) {
 	__rodata16 = .;
 	*(.rodata16)
diff --git a/src/arch/i386/scripts/i386.lds b/src/arch/i386/scripts/i386.lds
index 30776092..6adb6b99 100644
--- a/src/arch/i386/scripts/i386.lds
+++ b/src/arch/i386/scripts/i386.lds
@@ -65,6 +65,8 @@ SECTIONS {
     . = _text16_link_addr;
     _text16 = .;
 
+    . += 1;			/* Prevent NULL being valid */
+
     .text16 : AT ( _text16_load_offset + __text16 ) {
 	__text16 = .;
 	*(.text16)
@@ -78,6 +80,8 @@ SECTIONS {
     . = _data16_link_addr;
     _data16 = .;
 
+    . += 1;			/* Prevent NULL being valid */
+
     .rodata16 : AT ( _data16_load_offset + __rodata16 ) {
 	__rodata16 = .;
 	*(.rodata16)
@@ -115,6 +119,8 @@ SECTIONS {
 
     _text = .;
 
+    . += 1;			/* Prevent NULL being valid */
+
     .text : AT ( _textdata_load_offset + __text ) {
 	__text = .;
 	*(.text.null_trap)