From a9043ebf7209fb4dc9adafa6c71e6482dd4c8794 Mon Sep 17 00:00:00 2001
From: stefan <stefan@315a16e6-25f9-4109-90ae-ca3045a26c18>
Date: Thu, 5 Aug 2010 12:41:38 +0000
Subject: [PATCH] - create GDTs for user applications (ring 3) - rename section
 osstart to multiboot

git-svn-id: http://svn.lfbs.rwth-aachen.de/svn/scc/trunk/MetalSVM@43 315a16e6-25f9-4109-90ae-ca3045a26c18
---
 arch/x86/kernel/entry.asm |  2 +-
 arch/x86/kernel/gdt.c     | 12 +++++++++++-
 link.ld                   |  2 +-
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/entry.asm b/arch/x86/kernel/entry.asm
index 84f179ec..fa90d597 100644
--- a/arch/x86/kernel/entry.asm
+++ b/arch/x86/kernel/entry.asm
@@ -24,7 +24,7 @@
 [BITS 32]
 ; We use a special name to map this section at the begin of our kernel
 ; =>  Multiboot needs its magic number at the begin of the kernel
-SECTION .osstart
+SECTION multiboot
 global start
 start:
     mov esp, _sys_stack     ; This points the stack to our new stack area
diff --git a/arch/x86/kernel/gdt.c b/arch/x86/kernel/gdt.c
index 1b0b1651..78fe7730 100644
--- a/arch/x86/kernel/gdt.c
+++ b/arch/x86/kernel/gdt.c
@@ -34,7 +34,7 @@ struct gdt_ptr {
 	unsigned int base;
 } __attribute__ ((packed));
 
-#define GDT_ENTRIES	3
+#define GDT_ENTRIES	5
 
 struct gdt_entry gdt[GDT_ENTRIES];
 struct gdt_ptr gp;
@@ -94,6 +94,16 @@ void gdt_install(void)
 	 */
 	gdt_set_gate(2, 0, 0xFFFFFFFF, 0x92, 0xCF);
 		
+	/*
+	 * Create code segement for userspace applications (ring 3)
+	 */
+	gdt_set_gate(3, 0, 0xFFFFFFFF, 0xFA, 0xCF);
+
+	/*
+	 * Create data segement for userspace applications (ring 3)
+	 */
+	gdt_set_gate(4, 0, 0xFFFFFFFF, 0xF2, 0xCF);
+
 	/* Flush out the old GDT and install the new changes! */
 	gdt_flush();
 }
diff --git a/link.ld b/link.ld
index e8573ddb..ab752f97 100644
--- a/link.ld
+++ b/link.ld
@@ -6,7 +6,7 @@ SECTIONS
 {
   .text phys : AT(phys) {
     code = .;
-    *(.osstart)
+    *(multiboot)
     *(.text)
     *(.rodata)
     . = ALIGN(4096);