how to use bochs

[vinise]

Hy everyone

i've got to write a boot sequence for school... i'm actually using a amaising floppy disk and rebooting a computer over and over again ... i'm getting sick...

anyway i've find bochs but i dont find how to use it right.

i use nasm to make binary file (nasm boots.asm -o boots.bin -f bin)
and dd to transfer it into my flopy (dd if=boot.bin of=/dev/sda0)

how can i do the same with bochs?

[HitmanYesman]

This should do it:

Code: Select all

romimage: file=BIOS-bochs-latest, address=0xf0000 
vgaromimage: file=VGABIOS-lgpl-latest 

floppya: 1_44=a:, status=inserted
 
log: report.log

It essentially boots off whatever is inside the floppy a: drive.

[vinise]

Message: ROM: System BIOS must end at 0xfffff

and if i'm using bochs it's to stop using a real floppy.... how can i create and use img?

[f2]

Message: ROM: System BIOS must end at 0xfffff

Replace address=0xf0000 by address=0xe0000. The size of the Bochs BIOS is 128kb, not 64kb.

and if i'm using bochs it's to stop using a real floppy.... how can i create and use img?

RawWrite can do that.

[vinise]

RawWrite make img out off a floppy...
i want to make img from mine binary file... and boot on my binarry file

[Hangin10]

http://wiki.osdev.org/Virtual_Floppy_Disk

Next time, search the wiki first.

[vinise]

http://wiki.osdev.org/Virtual_Floppy_Disk

Next time, search the wiki first.

very not useful for linux :/

[Combuster]

dd can be used just as well for image files as it can be used for actual devices. But Hangin is right - there are a ton of methods to create images, if only you bothered to search. Shame on you for not finding the first entry in the frequently asked questions.

[vinise]

dd can be used just as well for image files as it can be used for actual devices. But Hangin is right - there are a ton of methods to create images, if only you bothered to search. Shame on you for not finding the first entry in the frequently asked questions.

if you're speaking of this http://wiki.osdev.org/Disk_Images i've seen it and try... but it's not working... i may do something wrong ere is what's im doing:

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dd if=/dev/zero of=floppy.flp bs=512 count=2880
nasm boot1.asm -o boot1.bin -f bin
dd if=boot1.bin of=floppy.flp

cat .bochsrc

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romimage: file=/usr/share/bochs/BIOS-bochs-latest, address=0xe0000
vgaromimage: file=/usr/share/bochs/VGABIOS-lgpl-latest

floppya: 1_44=~/floppy.flp, status=inserted

log: report.log

and when i run bochs i get :
Booting from Floppy...
Boot failed could not read the boot disk

FATAL: No bootable device.

[Thomas]

Hi ,

Code: Select all

dd if=/dev/zero of=floppy.flp bs=512 count=2880
nasm boot1.asm -o boot1.bin -f bin
dd if=boot1.bin of=floppy.flp

Use this instead .

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dd if=boot1.bin of=floppy.flp conv= notrunc seek=0

If you have noticed the size of the floopy img reduces to 512 bytes after your last command . I have to look at the dd manual though , I do not have a linux box at my desk.

--Thomas

[vinise]

hy
i've look the all night...

thanks Thomas... it was a part of the problem but the other part came from my boot sequence

I used to do the boot signature as :

Code: Select all

DB    0x55,0xAA

and it's not working with bochs ... a bit strange... it's working find with a real floppy and a computer
anyway i put

Code: Select all

DW    0x55AA

and it's working just fine


Thanks to every one

[Owen]

One word: Endian

[egos]

Code: Select all

DB    0x55,0xAA

This is right.

Code: Select all

DW    0x55AA

But this is not.