From a8968330aff45e0b8cf278f49fa337d5fcb9bfd8 Mon Sep 17 00:00:00 2001
From: Alex AUVOLAT <alex.auvolat@ens.fr>
Date: Fri, 28 Mar 2014 17:09:15 +0100
Subject: Import and compile code for article 6.5

---
 sos-code-article6.5/bootstrap/multiboot.S | 85 +++++++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)
 create mode 100644 sos-code-article6.5/bootstrap/multiboot.S

(limited to 'sos-code-article6.5/bootstrap/multiboot.S')

diff --git a/sos-code-article6.5/bootstrap/multiboot.S b/sos-code-article6.5/bootstrap/multiboot.S
new file mode 100644
index 0000000..546d947
--- /dev/null
+++ b/sos-code-article6.5/bootstrap/multiboot.S
@@ -0,0 +1,85 @@
+/* Copyright (C) 1999  Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; either version 2
+   of the License, or (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+   USA. 
+*/
+
+	
+/* The operating system is booted by Grub, so we almost have nothing
+   to do to boot it. We only have to conform to the Multiboot
+   standard, as defined by the Grub documentation */
+	
+#define ASM 1
+/* The multiboot.h header contains a lot of multiboot standard
+   definitions */
+#include "multiboot.h"
+
+	/* The multiboot header itself. It must come first. */
+.section ".multiboot"
+	/* Multiboot header must be aligned on a 4-byte boundary */
+	.align 4
+multiboot_header:
+  /* magic=        */ .long MULTIBOOT_HEADER_MAGIC
+  /* flags=        */ .long MULTIBOOT_HEADER_FLAGS
+  /* checksum=     */ .long -(MULTIBOOT_HEADER_MAGIC \
+                              +MULTIBOOT_HEADER_FLAGS)
+  /* header_addr=  */ .long multiboot_header
+  /* load_addr=    */ .long __b_load
+  /* load_end_addr=*/ .long __e_load
+  /* bss_end_addr= */ .long __e_kernel
+  /* entry_addr=   */ .long multiboot_entry
+	
+/* Here is the beginning of the code of our operating system */
+.text
+
+.globl start, _start
+start:
+_start:
+multiboot_entry:
+	/* Set up a stack */
+	movl $(stack + MULTIBOOT_STACK_SIZE), %ebp
+	movl %ebp, %esp
+
+	/* Set EFLAGS to 0 */
+	pushl $0
+	/* pop stack into the EFLAGS register */
+	popf
+
+	/* Push the magic and the address on the stack, so that they
+	will be the parameters of the cmain function */
+	pushl %ebx
+	pushl %eax
+
+	/* Call the cmain function (os.c) */
+	call EXT_C(sos_main)
+
+	/* Should never get there */
+loop:
+	hlt
+	jmp loop
+
+/* Here is the stack */
+.section ".init_stack", "aw", @nobits
+.size stack, MULTIBOOT_STACK_SIZE
+stack:
+	.space MULTIBOOT_STACK_SIZE
+
+/* Some data characterizing the stack addresses */
+.data
+	.globl bootstrap_stack_bottom
+bootstrap_stack_bottom: .long stack
+
+	.globl bootstrap_stack_size
+bootstrap_stack_size: .long MULTIBOOT_STACK_SIZE
-- 
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