From 0af8964008cc4fbbbaa55eaaae30ad624bca5e20 Mon Sep 17 00:00:00 2001
From: sbosse <sbosse@uni-bremen.de>
Date: Mon, 14 Oct 2024 23:08:58 +0200
Subject: [PATCH] Mon 14 Oct 23:06:38 CEST 2024

---
 kernel/memorylayout.h | 80 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 kernel/memorylayout.h

diff --git a/kernel/memorylayout.h b/kernel/memorylayout.h
new file mode 100644
index 0000000..1044215
--- /dev/null
+++ b/kernel/memorylayout.h
@@ -0,0 +1,80 @@
+/*
+Copyright (C) 2015-2019 The University of Notre Dame
+This software is distributed under the GNU General Public License.
+See the file LICENSE for details.
+*/
+
+/*
+This file describes the basic memory layout of the machine,
+and is included by both C and assembly code, so it can only
+contain #defines.
+*/
+
+/*
+Note that addresses in 16-bit mode are described as segment+offset,
+where the segment must be aligned on a 16-byte boundary.
+So, BOOTBLOCK_START = BOOTBLOCK_SEGMENT<<4 + BOOTBLOCK_OFFSET
+*/
+
+/*
+The bootblock is loaded at the fixed address of 0x7c00,
+which is a constant defined by the PC hardware.
+*/
+
+#define BOOTBLOCK_START   0x7c00
+#define BOOTBLOCK_SEGMENT 0x07c0
+#define BOOTBLOCK_OFFSET  0x0000
+
+/*
+We choose the initial stack to start at 0xfff0 and grow
+downward.  This stack location is used in the startup code,
+and by the kernel when no process is active.
+*/
+
+#define INTERRUPT_STACK_TOP     0xfff0
+#define INTERRUPT_STACK_SEGMENT 0x0000
+#define INTERRUPT_STACK_OFFSET  0xfff0
+
+/*
+We choose the kernel code to start at 0x10000 (64KB).
+Code is loaded into this location by the bootblock.
+*/
+
+#define KERNEL_START   0x10000
+#define KERNEL_SEGMENT 0x1000
+#define KERNEL_OFFSET  0x0000
+
+/*
+The total size of the kernel (in bytes) is stored at this
+offset, relative to the start of the kernel code.
+The bootblock uses this to decide how much to load from disk.
+*/
+
+#define KERNEL_SIZE_OFFSET 20
+
+/*
+Following the kernel code is a direct mapper memory area
+set aside for kmalloc() which implements a list of small
+memory allocations for internal kernel purposes.
+*/
+
+#define KMALLOC_START  0x100000
+#define KMALLOC_LENGTH 0x100000
+
+/*
+Main memory starts at the 2MB boundary following the kmalloc area.
+This area is tracked by memory.c and used for allocatable pages, which can
+be consumed by either the kernel or user processes.  The end of
+main memory is determined dynamically at bootup time.
+*/
+
+#define MAIN_MEMORY_START  0x200000
+
+/*
+We choose the user-mode address space to begin at 0x80000000,
+and the user-mode stack to start at the top of memory and
+grow down.  Addresses below 0x80000000 are all supervisor mode.
+*/
+
+#define PROCESS_ENTRY_POINT 0x80000000
+#define PROCESS_STACK_INIT  0xfffffff0