multiboot.lisp

   1 ;;;;------------------------------------------------------------------
   2 ;;;;
   3 ;;;;    Copyright (C) 2001-2002, 2004,
   4 ;;;;    Department of Computer Science, University of Tromso, Norway.
   5 ;;;;
   6 ;;;;    For distribution policy, see the accompanying file COPYING.
   7 ;;;;
   8 ;;;; Filename:      multiboot.lisp
   9 ;;;; Description:
  10 ;;;; Author:        Frode Vatvedt Fjeld <frodef@acm.org>
  11 ;;;; Created at:    Wed Jun 12 12:14:12 2002
  12 ;;;;
  13 ;;;; $Id: multiboot.lisp,v 1.5 2004/07/28 14:23:37 ffjeld Exp $
  14 ;;;;
  15 ;;;;------------------------------------------------------------------
  16
  17 (in-package movitz)
  18
  19 ;;;    The layout of the Multiboot header must be as follows:
  20 ;;;
  21 ;;;    Offset  Type    Field Name     Note
  22 ;;;    0       u32     magic          required
  23 ;;;    4       u32     flags          required
  24 ;;;    8       u32     checksum       required
  25 ;;;    12      u32     header_addr    if flags[16] is set
  26 ;;;    16      u32     load_addr      if flags[16] is set
  27 ;;;    20      u32     load_end_addr  if flags[16] is set
  28 ;;;    24      u32     bss_end_addr   if flags[16] is set
  29 ;;;    28      u32     entry_addr     if flags[16] is set
  30 ;;;    32      u32     mode_type      if flags[2] is set
  31 ;;;    36      u32     width          if flags[2] is set
  32 ;;;    40      u32     height         if flags[2] is set
  33 ;;;    44      u32     depth          if flags[2] is set
  34
  35
  36 (defconstant +multiboot-header-magic-value+  #x1BADB002)
  37
  38 (define-binary-class multiboot-header (movitz-heap-object)
  39   ((scan-skip-header
  40     :binary-type lu32
  41     :initform +scan-skip-word+)
  42    (scan-skip-length
  43     :binary-type lu32
  44     :initform 0
  45     :map-binary-write (lambda (x type)
  46                         (declare (ignore x type))
  47                         (- (sizeof 'multiboot-header) 8)))
  48    (magic
  49     :accessor magic
  50     :initform +multiboot-header-magic-value+
  51     :initarg :magic
  52     :binary-type lu32)
  53    (flags
  54     :accessor flags
  55     :initarg :flags
  56     :initform '(:addresses-included)
  57     :binary-type (define-bitfield multiboot-flags (lu32)
  58                    (((:bits)
  59                      ;; Align modules to 4K boundaries?
  60                      :align-modules-4k 0
  61                      ;; Pass memory information to the kernel?
  62                      :pass-memory-info 1
  63                      ;; Pass video modes information to the kernel
  64                      :pass-video-info  2
  65                      ;; Is the address fiels below included in the header?
  66                      :addresses-included 16))))
  67    (checksum
  68     :accessor checksum
  69     :initform (ldb (byte 32 0)
  70                    (- (+ +multiboot-header-magic-value+
  71                          (enum-value 'multiboot-flags '(:addresses-included)))))
  72     :binary-type lu32)
  73    (header-address
  74     ;; Contains the address corresponding to the beginning of the
  75     ;; Multiboot header -- the physical memory location at which the
  76     ;; magic value is supposed to be loaded. This field serves to
  77     ;; "synchronize" the mapping between OS image offsets and physical
  78     ;; memory addresses.
  79     :accessor header-address
  80     :initarg :header-address
  81     :binary-type lu32)
  82    (load-address
  83     ;; Contains the physical address of the beginning of the text
  84     ;; segment. The offset in the OS image file at which to start
  85     ;; loading is defined by the offset at which the header was found,
  86     ;; minus (header_addr - load_addr). load_addr must be less than or
  87     ;; equal to header_addr.
  88     :accessor load-address
  89     :initarg :load-address
  90     :binary-type lu32)
  91    (load-end-address
  92     ;; Contains the physical address of the end of the data segment.
  93     ;; (load_end_addr - load_addr) specifies how much data to load.
  94     ;; This implies that the text and data segments must be
  95     ;; consecutive in the OS image; this is true for existing a.out
  96     ;; executable formats.  If this field is zero, the boot loader
  97     ;; assumes that the text and data segments occupy the whole OS
  98     ;; image file.
  99     :accessor load-end-address
 100     :initarg :load-end-address
 101     :binary-type lu32)
 102    (bss-end-address
 103     ;; Contains the physical address of the end of the bss
 104     ;; segment. The boot loader initializes this area to zero, and
 105     ;; reserves the memory it occupies to avoid placing boot modules
 106     ;; and other data relevant to the operating system in that
 107     ;; area. If this field is zero, the boot loader assumes that no
 108     ;; bss segment is present.
 109     :accessor bss-end-address
 110     :initarg :bss-end-address
 111     :initform 0
 112     :binary-type lu32)
 113    (entry-address
 114     ;; The physical address to which the boot loader should jump in
 115     ;; order to start running the operating system.
 116     :accessor entry-address
 117     :initarg :entry-address
 118     :binary-type lu32)
 119    (video-mode-type
 120     ;; Valid numbers for `mode_type' is 0 for linear graphics mode and
 121     ;; 1 for EGA-standard text mode. Everything else is reserved for
 122     ;; future expansion. Please note that even if you set this field
 123     ;; to indicate that you want a graphics mode, you might get a text
 124     ;; mode.
 125     :accessor video-mode-type
 126     :initarg :video-mode-type
 127     :initform 0
 128     :binary-type lu32)
 129    (video-width
 130     ;; `width' and `height' is specified in pixels, if graphics mode,
 131     ;; or characters in EGA text mode. `depth' is given in bits per
 132     ;; pixel for graphics, or zero for EGA text modes.
 133     :accessor video-width
 134     :initarg :video-width
 135     :initform 0
 136     :binary-type lu32)
 137    (video-height
 138     :accessor video-height
 139     :initarg :video-height
 140     :initform 0
 141     :binary-type lu32)
 142    (video-depth
 143     :accessor video-depth
 144     :initarg :video-depth
 145     :initform 0
 146     :binary-type lu32)))
 147
 148 (defmethod movitz-object-offset ((obj multiboot-header)) 0)