We shall install both bochs and bochs-x packages first to realize further examples in this book.
# sudo apt-get install bochs bochs-x
boot.s
.globl begtext, begdata, begbss, endtext, enddata, endbss
.text
begtext:
.data
begdata:
.bss
begbss:
.text
BOOTSEG=0x07c0
entry start
start:
jmpi go, BOOTSEG
go: mov ax, cs
mov ds, ax
mov es, ax
mov [msg1+17], ah
mov cx, #20
mov dx, #0x1004
mov bx, #0x000c
mov bp, #msg1
mov ax, #0x1301
int 0x10
loop1: jmp loop1
msg1: .ascii "Loading system ..."
.byte 13, 10
.org 510
.word 0xAA55
.text
endtext:
.data
enddata:
.bss
endbss:
# as86 -0 -a -o boot.o boot.s
# ld86 -0 -s -o boot boot.o
# dd bs=32 if=boot of=boot.img skip=1
Now we'll start bochs to test our boot image. However we shall edit the configuration before testing. I tried in this way
# bochs
========================================================================
Bochs x86 Emulator 2.4.2
Build from CVS snapshot on November 12, 2009
========================================================================
00000000000i[ ] LTDL_LIBRARY_PATH not set. using compile time default '/usr/lib/bochs/plugins'
00000000000i[ ] BXSHARE not set. using compile time default '/usr/share/bochs'
00000000000e[ ] Switching off quick start, because no configuration file was found.
------------------------------
Bochs Configuration: Main Menu
------------------------------
This is the Bochs Configuration Interface, where you can describe the
machine that you want to simulate. Bochs has already searched for a
configuration file (typically called bochsrc.txt) and loaded it if it
could be found. When you are satisfied with the configuration, go
ahead and start the simulation.
You can also start bochs with the -q option to skip these menus.
1. Restore factory default configuration
2. Read options from...
3. Edit options
4. Save options to...
5. Restore the Bochs state from...
6. Begin simulation
7. Quit now
Please choose one: [2] 3
------------------
Bochs Options Menu
------------------
0. Return to previous menu
1. Logfile options
2. Log options for all devices
3. Log options for individual devices
4. CPU options
5. Memory options
6. Clock & CMOS options
7. PCI options
8. Bochs Display & Interface options
9. Keyboard & Mouse options
10. Disk options
11. Serial / Parallel / USB options
12. Network card options
13. Sound Blaster 16 options
14. Other options
15. User-defined options
Please choose one: [0] 10
------------------
Bochs Disk Options
------------------
0. Return to previous menu
1. First Floppy Drive
2. Second Floppy Drive
3. ATA channel 0
4. First HD/CD on channel 0
5. Second HD/CD on channel 0
6. ATA channel 1
7. First HD/CD on channel 1
8. Second HD/CD on channel 1
9. ATA channel 2
10. First HD/CD on channel 2 (disabled)
11. Second HD/CD on channel 2 (disabled)
12. ATA channel 3
13. First HD/CD on channel 3 (disabled)
14. Second HD/CD on channel 3 (disabled)
15. Boot Options
Please choose one: [0] 1
------------------
First Floppy Drive
------------------
What type of floppy drive? [none] ?
Type of floppy drive
Valid values are: none, 5.25" 360K, 5.25" 1.2M, 3.5" 720K, 3.5" 1.44M, 3.5" 2.88M
What type of floppy drive? [none] 3.5" 1.44M
Enter new filename, or 'none' for no disk: [none] /home/yenping/workspace/boot.img
What type of floppy media? (auto=detect) [none] ?
Type of floppy media
Valid values are: none, 1.2M, 1.44M, 2.88M, 720K, 360K, 160K, 180K, 320K, auto
What type of floppy media? (auto=detect) [none] 1.44M
Is media inserted in drive? [no] yes
------------------
Bochs Disk Options
------------------
0. Return to previous menu
1. First Floppy Drive
2. Second Floppy Drive
3. ATA channel 0
4. First HD/CD on channel 0
5. Second HD/CD on channel 0
6. ATA channel 1
7. First HD/CD on channel 1
8. Second HD/CD on channel 1
9. ATA channel 2
10. First HD/CD on channel 2 (disabled)
11. Second HD/CD on channel 2 (disabled)
12. ATA channel 3
13. First HD/CD on channel 3 (disabled)
14. Second HD/CD on channel 3 (disabled)
15. Boot Options
Please choose one: [0] 15
------------
Boot Options
------------
0. Return to previous menu
1. Boot drive #1: floppy
2. Boot drive #2: none
3. Boot drive #3: none
4. Skip Floppy Boot Signature Check: no
5. 32-bit OS Loader Hack
Please choose one: [0] 0
------------------
Bochs Disk Options
------------------
0. Return to previous menu
1. First Floppy Drive
2. Second Floppy Drive
3. ATA channel 0
4. First HD/CD on channel 0
5. Second HD/CD on channel 0
6. ATA channel 1
7. First HD/CD on channel 1
8. Second HD/CD on channel 1
9. ATA channel 2
10. First HD/CD on channel 2 (disabled)
11. Second HD/CD on channel 2 (disabled)
12. ATA channel 3
13. First HD/CD on channel 3 (disabled)
14. Second HD/CD on channel 3 (disabled)
15. Boot Options
Please choose one: [0] 0
------------------
Bochs Options Menu
------------------
0. Return to previous menu
1. Logfile options
2. Log options for all devices
3. Log options for individual devices
4. CPU options
5. Memory options
6. Clock & CMOS options
7. PCI options
8. Bochs Display & Interface options
9. Keyboard & Mouse options
10. Disk options
11. Serial / Parallel / USB options
12. Network card options
13. Sound Blaster 16 options
14. Other options
15. User-defined options
Please choose one: [0] 0
------------------------------
Bochs Configuration: Main Menu
------------------------------
This is the Bochs Configuration Interface, where you can describe the
machine that you want to simulate. Bochs has already searched for a
configuration file (typically called bochsrc.txt) and loaded it if it
could be found. When you are satisfied with the configuration, go
ahead and start the simulation.
You can also start bochs with the -q option to skip these menus.
1. Restore factory default configuration
2. Read options from...
3. Edit options
4. Save options to...
5. Restore the Bochs state from...
6. Begin simulation
7. Quit now
Please choose one: [6] 4
Save configuration to what file? To cancel, type 'none'.
[none] myBochs.cfg
00000000000i[ ] write current configuration to myBochs.cfg
Wrote configuration to 'myBochs.cfg'.
------------------------------
Bochs Configuration: Main Menu
------------------------------
This is the Bochs Configuration Interface, where you can describe the
machine that you want to simulate. Bochs has already searched for a
configuration file (typically called bochsrc.txt) and loaded it if it
could be found. When you are satisfied with the configuration, go
ahead and start the simulation.
You can also start bochs with the -q option to skip these menus.
1. Restore factory default configuration
2. Read options from...
3. Edit options
4. Save options to...
5. Restore the Bochs state from...
6. Begin simulation
7. Quit now
Please choose one: [6] 6
Next time, we can start bochs with our config as below.
# bochs -f myBochs.cfg
