Re: [colorforth] Booting from HDD
- Subject: Re: [colorforth] Booting from HDD
- From: Nick Maroudas <alice@xxxxxxxxxxxxxxxxxxxxxxx>
- Date: Mon, 17 Mar 2008 11:16:00 +0200
Nick here,
Thanks Ray, for your boot.asm printout (below). It
shows a boot process that has already set up video
4FO2/4117 and copied the 512 byte boot sector before
relocating to "at0:" to copy the remaining code via
floppy then jumping to "start2" via the floppy call
"stop" motor. For comparison, here is JC's boot.asm.
Unlike yours (or Howerd's original CFDOS4 floppy) this
CD version does not set up video before relocating, and
seems to rely on MSDOS or ElTorito (non-emulation
mode) to have copied all of the code before setting up
the Graphic Output Display ("god"). See lines 98, 99 in
JC's version (below). This is a long way from the
simplicity of Chuck's original boot.asm (which one can
consult on JC's site under "as/", together with a very
helpful commentary by John himself). As Albert van der
Horst has just remarked, "CF is simple but this is the
other side of the coin". I find that Howerd's
CFDOS4.blk (simply DeeDee'd onto a floppy) boots a new
Pentium D with no OS apart from BIOS, but John's CFDOS4
CD does not.
IMHO Jason is on the right track: floppy emulation; just
dd a reliable floppy image onto the flash stick
(after all, CF is meant to be self booting). I could
expatiate if anyone is interested.
Caritas,
NickM
JC's boot.asm
http://colorforth.cvs.sourceforge.net/colorforth/colorforth/jc2007/boot.asm?revision=1.69&view=markup
intel_syntax ;# floppy boot segment
2 ;# 0x000-0x400 is BIOS interrupt table
3 ;# 0x400-0x500 is BIOS system information area
4 ;# we can use starting at 0x500
5
6 .equ upper_right, 158 ;# address of upper-right
corner of screen
7 .ifdef LOADBLOCKS
8 ;# this 'ifdef' is only here to trigger the
Makefile to include this number
9 ;# but let's use it to define other constants
while we're at it
10 .equ HEADS, 2
11 .equ SECTORS_PER_TRACK, 18
12 .equ BYTES_PER_CYLINDER, 512 * HEADS *
SECTORS_PER_TRACK
13 .equ LOAD_CYLINDERS, (LOADBLOCKS * 1024) /
BYTES_PER_CYLINDER
14 .if (LOADBLOCKS * 1024) % BYTES_PER_CYLINDER > 0
15 .equ LOAD_CYLINDERS, LOAD_CYLINDERS + 1
16 .endif
17 .endif
18 .macro showprogress
19 .ifdef DEBUGGING
20 call progress
21 .endif
22 .endm
23 .macro shownumber
24 .ifdef DEBUGGING
25 call shownumber
26 .endif
27 .endm
28
29 .org 0 ;# actually 0x7c00, where the BIOS loads
the bootsector
30 start:
31 jmp start0
32 bootmode: ;# this byte after the short jmp above
is normally just padding
33 ;# we will use it to indicate a startup from
MSDOS
34 ;# also to indicate El Torito boot
35 .ifdef EL_TORITO_BOOT
36 .byte 0xfe ;# even number so we can use MSDOS
check odd parity
37 .else
38 .byte 0 ;# pad to offset 3
39 .endif
40 .ascii "cmcf 1.0"
41 bps:
42 .word 512 ;# bytes/sector
43 .byte 1 ;# sector/cluster
44 .word 1 ;# sector reserved
45 .byte 2 ;# fats
46 .word 16*14 ;# root directory entries
47 .word 80 * HEADS * SECTORS_PER_TRACK ;#
sectors
48 .byte 0x0f0 ;# media
49 .word 9 ;# sectors/fat
50 spt:
51 .word SECTORS_PER_TRACK ;# sectors/track
52 heads:
53 .word HEADS ;# heads
54 .long 0 ;# hidden sectors
55 .long 80 * HEADS * SECTORS_PER_TRACK ;#
sectors again
56 drive:
57 .byte 0 ;# drive
58 cylinder: .word 0
59 .align 4
60 ;# forth+icons+blocks 24-LOADBLOCKS ;# number of
cylinders to load (out of 80)
61 ;# needs to be on longword boundary, see nc_ in
color.asm
62 nc: .long LOAD_CYLINDERS
63 gdt: .word gdt_end - gdt0 - 1 ;# GDT limit
64 .long gdt0 + loadaddr ;# pointer to start of
table
65 .align 8
66 gdt0: .word 0, 0, 0, 0 ;# start of table must be
a
null entry
67 .equ code32p, . - gdt0
68 .word 0xffff, 0, 0x9a00, 0xcf ;# 32-bit
protected-mode code
69 .equ data32p, . - gdt0
70 .word 0xffff, 0, 0x9200, 0xcf ;# 32-bit
protected-mode data
71 .equ code16r, . - gdt0
72 .word 0xffff, 0, 0x9a00, 0x00 ;# 16-bit
real-mode code
73 .equ data16r, . - gdt0
74 .word 0xffff, 0, 0x9200, 0x00 ;# 16-bit
real-mode data
75 gdt_end:
76 real_mode_idt:
77 .word 0xffff ;# limit
78 .long 0 ;# base is that of BIOS interrupt
table
79 .code16
80 start0:
81 cmp word ptr cs:0, 0x20cd ;# INT 20h at
start
of .com program header
82 jnz 0f
83 dec byte ptr [cs: bootmode + 0x100]
84 0: cli
85 push cs ;# need to set DS=CS, especially on
VMWare, DS was 0x40
86 pop ds
87 zero ss ;# set stack to something low and out
of the way
88 mov esp, iobuffer + 0x1000
89 call whereami ;# set EBP to load location
90 call relocate ;# move past BIOS stuff and
buffer space
91 mov esp, gods ;# stack pointer now where it
really belongs
92 call whereami ;# set EBP to where we
relocated
93 showprogress
94 data32 call protected_mode
95 .code32
96 call a20 ;# set A20 gate to enable access to
addresses with 1xxxxx
97 mov al, byte ptr bootmode + loadaddr
98 or al, al ;# negative if MSDOS-loaded or
El
Torito non-emulation mode
99 jz 0f ;# otherwise we need to load bootcode
from floppy
100 9: mov esi, godd ;# set up data stack pointer
for 'god' task
101 jmp start1
102 0: mov byte ptr [es: 0xb8000 | (upper_right -
8)], 'P'
103 call unreal_mode
104 .code16
105 ;# fall through to cold-start routine
106 cold:
107 mov edi, loadaddr ;# start by overwriting
this code
108 ;# that's why it's so critical that
'cylinder'
be reset to zero before
109 ;# saving the image; if it's anything but
that, when this block is
110 ;# overwritten, 'cylinder' will be changed,
and cylinders will be skipped
111 ;# in loading, making the bootblock unusable
112 call read
113 inc byte ptr cylinder + loadaddr
114 xor cx, cx
115 mov cl, nc + loadaddr ;# number of cylinders
used
116 dec cx
117 0: push cx
118 call read
119 inc byte ptr cylinder + loadaddr
120 mov dx, word ptr cylinder + loadaddr
121 shownumber
122 pop cx
123 loop 0b
124 showprogress
125 data32 call protected_mode
**********************
Quoting "Ray St. Marie" <ray.stmarie@xxxxxxxxx>:
>... " On Sat, Mar 15, 2008 at 5:25 PM, Ray St. Marie
>... " <ray.stmarie@xxxxxxxxx> wrote:
>... " >
>
>... " > --
>... " > Raymond St. Marie ii,
>... " > colorforthray.info
>... " >
>... "
>... " Microsoft (R) Macro Assembler Version
>... " 6.14.8444 10/12/07 23:04:39
>... " color.asm Page 1 - 1
>... "
>... "
>... " ;colorForth, 2001 Jul 22, Chuck Moore,
>... " Public Domain
>... " ;modified 8/06/01 for 800x600 operation
>... " Terry Loveall, loveall@xxxxxxxxx
>... " ;modified ras20040728 returned to 1024x768
>... " operation for the pentium 4
>... " ;by Ray St. Marie
>... " Rastm2@xxxxxxxxxxxxxxxxxxxxx
>... " .MODEL tiny
>... " .486p
>... " 00000000 only SEGMENT USE32
>... " ASSUME DS:only
>... "
>... " next MACRO adr
>... " dec ECX
>... " jnz adr
>... " ENDM
>... "
>... " DUP_ MACRO
>... " lea ESI, [ESI-4]
>... " mov [ESI], EAX
>... " ENDM
>... "
>... " DROP MACRO
>... " lodsd
>... " ENDM
>... "
>... " ;;hp equ 800
>... " ;;vp equ 600
>... " ;;vesa equ 114h
>... " = 00000400 hp equ 1024
>... " = 00000300 vp equ 768
>... " = 00004117 vesa equ 4117h ; 117h but with
>... " LinearFrameBuffer Bit on
>... " = 00025C00 buffer equ 604*256
>... " include boot.asm ; boot boot0 hard
>... " C ; Floppy boot segment
>... " C
>... " C org 0 ; actually 7c00
>... " 00000000 EB 56 C start: jmp start0
>... " 00000002 90 C nop
>... " C
>... " 00000003 63 6D 63 66 20 C db 'cmcf
>... " 1.0'
>... " 31 2E 30
>... " 0000000B 0200 C dw 512 ;
>... " bytes/sector
>... " 0000000D 01 C db 1 ;
>... " sector/cluster
>... " 0000000E 0001 C dw 1 ; sector
>... " reserved
>... " 00000010 02 C db 2 ; FATs
>... " 00000011 00E0 C dw 16*14 ; root
>... " directory entries
>... " 00000013 0B40 C dw 80*2*18 ;
>... " sectors
>... " 00000015 F0 C db 0F0h ; media
>... " 00000016 0009 C dw 9 ;
>... " sectors/FAT
>... " 00000018 0012 C dw 18 ;
>... " sectors/track
>... " 0000001A 0002 C dw 2 ; heads
>... " 0000001C 00000000 C dd 0 ;
>... " hidden sectors
>... " 00000020 00000B40 C dd 80*2*18 ;
>... " sectors again
>... " 00000024 00 C db 0 ; drive
>... " C ; db 0
>... " C ; db 29h ; signature
>... " C ; dd 44444444h ; serial
>... " C ; db 'COLOR FORTH' ; label
>... " C ; db ' '
>... " C
>... " 00000025 00 C command db 0
>... " 00000026 00 C db 0 ; head,
>... " drive
>... " 00000027 00 C cylinder db 0
>... " 00000028 00 C db 0 ; head
>... " 00000029 01 C db 1 ; sector
>... " 0000002A 02 C db 2 ; 512
>... " bytes/sector
>... " 0000002B 12 C db 18 ;
>... " sectors/track
>... " 0000002C 1B C db 1bh ; gap
>... " 0000002D FF C db 0ffh
>... " C ALIGN 4
>... " 00000030 00000012 C nc dd 18 ;
>... " Forth+Icons+blocks 24-161
>... " 00000034 0017 C gdt dw 17h
>... " 00000036 00000040 R C dd offset
>... " gdt0
>... " C ALIGN 8
>... " 00000040 0000 0000 0000 C gdt0 dw 0, 0, 0,
>... " 0
>... " 0000
>... " 00000048 FFFF 0000 9A00 C dw 0FFFFh,
>... " 0, 9A00h, 0CFh ; code
>... " 00CF
>... " 00000050 FFFF 0000 9200 C dw 0FFFFh,
>... " 0, 9200h, 0CFh ; data
>... " 00CF
>... " C
>... " C ; Code is compiled in Protected
>... " 32-bit mode.
>... " C ; Hence org $-2 to fix 16-bit
>... " words
>... " C ; and 4 hand-assembled instructions.
>... " C ; and EAX and AX exchanged
>... " C ; This code is in Real 16-bit mode
>... " C
>... " 00000058 B8 00004F02 C start0: mov EAX,
>... " 4F02h ; Video mode
>... " C org $-2
>... " 0000005B BB 00004117 C mov EBX,
>... " vesa ; hp*vp rgb: 565
>... " C org $-2
>... " 0000005E CD 10 C int 10h
>... " 00000060 FA C cli
>... " 00000061 66| 33 C0 C xor AX, AX
>... " ; Move code to 0
>... " 00000064 66| 8B D8 C mov BX, AX
>... " 00000067 8C CB C mov EBX, CS
>... " 00000069 8E DB C mov DS, EBX
>... " 0000006B 8E C0 C mov ES, EAX
>... " 0000006D 66| 8B F8 C mov DI, AX
>... " 00000070 66| 8B F0 C mov SI, AX
>... " 00000073 E8 00000000 C call $+5 ;
>... " Where are we? IP+4*CS
>... " C org $-2
>... " 00000076 5E C loc: pop ESI
>... " 00000077 81 EE 00000076 C sub ESI,
>... " offset loc-offset start
>... " C org $-2
>... " 0000007B B9 00000080 C mov ECX,
>... " 512/4
>... " C org $-2
>... " 0000007E F3/ 66| A5 C rep movsw
>... " C ; jmp 0:relocate
>... " 00000081 EA C db 0eah
>... " 00000082 0086 0000 C dw offset
>... " relocate-offset start, 0
>... " C
>... " 00000086 C relocate: ; This code is
>... " executed from 0
>... " 00000086 8E D8 C mov DS, EAX
>... " C ; lgdt fword ptr gdt
>... " 00000088 0F 01 16 C db 0fh, 1, 16h
>... " 0000008B 0034 C dw offset
>... " gdt-offset start
>... " 0000008D B0 01 C mov AL, 1
>... " 0000008F 0F 22 C0 C mov CR0, EAX
>... " C ; jmp 8:protected
>... " 00000092 EA C db 0eah
>... " 00000093 0097 0008 C dw offset
>... " protected-offset start, 8
>... " C
>... " 00000097 C protected: ; Now in Protected
>... " 32-bit mode
>... " 00000097 B0 10 C mov AL, 10h
>... " 00000099 8E D8 C mov DS, EAX
>... " 0000009B 8E C0 C mov ES, EAX
>... " 0000009D 8E D0 C mov SS, EAX
>... " 0000009F BC 000A0000 C mov ESP,
>... " Gods
>... " 000000A4 33 C9 C xor ECX, ECX
>... " C
>... "
>... " --
>... " Raymond St. Marie ii,
>... " colorforthray.info
>... "
>... "
---------------------------------------------------------------------
>... " To unsubscribe, e-mail:
>... " colorforth-unsubscribe@xxxxxxxxxxxxxxxxxx
>... " For additional commands, e-mail:
>... " colorforth-help@xxxxxxxxxxxxxxxxxx
>... " Main web page - http://www.colorforth.com
>... "
--
Dr Nicolas George Maroudas
Avigdor Meiri 9/1
Sea View
Haifa 3 55 00
Israel
Tel +972 048 337 315
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