Re: [Freedos-user] Big bootable disk for CD

[Alain M. <al...@po...>]

Em 15-06-2011 11:51, Alain Mouette escreveu:
>
> How can I make a big (6Mb) bootable image to use in the CD?
> This is the only part of the CD that I can read on *any* machine, I am
> using isolinux)

With lots of help fom Eric Auer, I managed to make a bootable image with 
FreeDOS. Here is how I did it:

1) Program needed: NASM, which I got from Debian
$ sudo apt-get install nasm

2) program from Eric for the boot sector:
<http://ericauer.cosmodata.virtuaserver.com.br/soft/specials/sys-freedos-linux.zip>
create a directory ./sys-freedos-linux and expand it there

3) create file of the right size. 5760k was ok for me, there is some 
magic in the size and not everything will be ok. (more studies needed)
$ dd if=/dev/zero of=FreeDOS.img count=11520
11520+0 records in
11520+0 records out
5898240 bytes (5.9 MB) copied, 0.408512 s, 14.4 MB/s

4) Prepare it with a FAT file system
$ sudo mkdosfs -v FreeDOS.img
mkdosfs 3.0.1 (23 Nov 2008)
FreeDOS.img has 64 heads and 32 sectors per track,
logical sector size is 512,
using 0xf8 media descriptor, with 11520 sectors;
file system has 2 12-bit FATs and 4 sectors per cluster.
FAT size is 9 sectors, and provides 2867 clusters.
Root directory contains 512 slots.
Volume ID is 0cbb7ca7, no volume label.

5) compile and write a suitable boot sector. This is a smart script by 
Eric Auer that configures it with the appropiate parameters
$ ./sys-freedos-linux/sys-freedos.pl --disk=FreeDOS.img
DOS boot sector for FreeDOS.img will be created by:
         nasm -o /dev/stdout -dISFAT12 
./sys-freedos-linux/bootsecs/boot.asm
Using FAT12. Partn offset 0, CHS *x64x32  Drive 0, (0x0, 0x29),
SerNo CBB-7CA7, Strings '           ',  'FAT12   '.
Boot sector successfully updated.

6) mount it in a directory
$ mkdir bootimg
$ sudo mount -v -o loop,uid=you,gid=you FreeDOS.img bootimg

7) copy into it KERNEL.SYS, COMMAND.COM and all other files

8) use it just the same way then the image made from a floppy, memdisk 
will recognize it. I used isolinux, here is how I created the iso:
$ mkisofs  -R -v -A "FreeDOS big boot CD" -V FreeDOS-V1.x     \
     -b isolinux/isolinux.bin -c isolinux/boot.cat             \
     -no-emul-boot -boot-load-size 4 -boot-info-table          \
     -o /mnt/dados/Segurver/FreeDOS-V1.x.iso                   \
     /mnt/dados/CDROM

Alain