Everything bootable with isolinux works with pxelinux?

this is my question:
all topics open about isolinux and multiboot cd or usb sticks are adoptable with pxelinux?

If I boot erd commander by isolinux on cd, I can have same result by network with pxeboot.

I would say yes, but most probably it will need some "individual" tweaking.

jaclaz

I would say yes, but most probably it will need some "individual" tweaking.

jaclaz

I'd like to create a HDDImage for memdisk from a DOS based ISO cd.

There is some guide for web.
I have read that memdisk for images greater than 2.88 MB is necessary specify cilinders, sectors, etc.
How I can calculate these values?

Either manually or using a tool to create and fdisk/format the image.

Easier would be to use QEMU (possibly with QEMU manager) accompanying tool to create a RAW image, than boot QEMU from a virtual DOS floppy, with the created image as virtual hard disk, and FDISK/FORMAT the image.

Then, all you need is opening the image, virtually mounted with VDK, (optionally through my pseudo_GUI for it, and check it's contents with PTEDIT32 or Beeblebrox.

Be warned that, depending on size of the image, QEMU might "sense" it with a different geometry both from the "default" of CHS Mx64x32 used by VDK and from the "default" Windows 2K/XP one of Nx255x63.

However, since the image has already (done in QEMU) a partiton and format, you can get the actual geometry of the image from the partition data, seen in one of the said utilities.
CHS End sector is the same of number of sectors.
CHS End head +1 = number of heads
CHS End cylinder+1= number of cylinders

You can use the little worksheet posted here:
http://www.boot-land...ions-t2959.html
to verify the data and compare them to actual size of the image.

What I would do is a bit more difficult at first, i.e. creating the image and mounting it in VDK with a given geometry (it is not actually difficult, but needs a little of accuracy), the procedure is explained here:
http://www.911cd.net...o...19056&st=49
(but do read a few posts before too)

The above applies to a HD image, i.e. one that has MBR+Hidden sectors, search on the same thread for other ways to make a filedisk image (a partition only or "superfloppy" image).

For this latter type of image you can also use Imdisk.

jaclaz

Either manually or using a tool to create and fdisk/format the image.

Easier would be to use QEMU (possibly with QEMU manager) accompanying tool to create a RAW image, than boot QEMU from a virtual DOS floppy, with the created image as virtual hard disk, and FDISK/FORMAT the image.

Then, all you need is opening the image, virtually mounted with VDK, (optionally through my pseudo_GUI for it, and check it's contents with PTEDIT32 or Beeblebrox.

Be warned that, depending on size of the image, QEMU might "sense" it with a different geometry both from the "default" of CHS Mx64x32 used by VDK and from the "default" Windows 2K/XP one of Nx255x63.

However, since the image has already (done in QEMU) a partiton and format, you can get the actual geometry of the image from the partition data, seen in one of the said utilities.
CHS End sector is the same of number of sectors.
CHS End head +1 = number of heads
CHS End cylinder+1= number of cylinders

You can use the little worksheet posted here:
http://www.boot-land...ions-t2959.html
to verify the data and compare them to actual size of the image.

What I would do is a bit more difficult at first, i.e. creating the image and mounting it in VDK with a given geometry (it is not actually difficult, but needs a little of accuracy), the procedure is explained here:
http://www.911cd.net...o...19056&st=49
(but do read a few posts before too)

The above applies to a HD image, i.e. one that has MBR+Hidden sectors, search on the same thread for other ways to make a filedisk image (a partition only or "superfloppy" image).

For this latter type of image you can also use Imdisk.

jaclaz

It could have to be more simple find a premade image, inject necessary files and calculate cylinder, sectors, heads.
Are There these images?

Well, there are some "pre-made" images, here:
http://bootcd.narod.ru/images_e.htm

but of course you never find the size "exactly" as you want/need it.

jaclaz

The images seem good. I'm trying to built a simple MSDOS floppy image with a 11.52 MB of size

Hey jaclaz I have tried with 11.52 image.

I have download win98 se floppy disk from bootdisk.com
I have deleted files in image and injected win98 files
I have changed Bootsector in win 95/98 with winimage

Memdisk load but there is some errors (see picture).



These are my code line in default file in pxelinux.cfg directory:

#Floppy Image 50 MB example
MENU LABEL ^12 Floppy Image 50 MB
kernel memdisk c=24 h=122 s=27 floppy
append initrd=fd050000.ima

What's the problem?

The one you tried appears to be the 50 Mb image fd050000.ima

Of course a couple of questions come to my mind :
1) Did the image work as it was (i.e. with the FreeDOS kernel) before you tampered with Winimage?
2) Where did you get that geometry?

c=24 h=122 s=27

The image, as is, appears having a geometry of
CHS 7x255x63

Moreover, it has a F8 "Media descriptor", though it is usually ignored, memdisk might check it (F8 means hard disk, should be F0 for floppy).

jaclaz

The one you tried appears to be the 50 Mb image fd050000.ima

Of course a couple of questions come to my mind :
1) Did the image work as it was (i.e. with the FreeDOS kernel) before you tampered with Winimage?
2) Where did you get that geometry?
The image, as is, appears having a geometry of
CHS 7x255x63

Moreover, it has a F8 "Media descriptor", though it is usually ignored, memdisk might check it (F8 means hard disk, should be F0 for floppy).

jaclaz

I have tried in VMware.
This image come with freedos.
I have tried it in VMware and it hang up during boot.
Here is what I see
Link here

This geometry is automatically suggest from memdisk durint boot.
How I can change media descriptor?

If I am not mistaken (but I remember using a relatively old version) VMWare does not support "superfloppies".

Since you own Winimage, can you experiment with it's "Export to a image with MBR" feature and see what happens in VMware?

Most probably the image geometry will be changed to a nx64x32 one, but all values should be corrected accordingly.

jaclaz

Wow!!

It's boot, but only with windows 98 bootfile.

These are my line in default file:

#Floppy Image 50 MB example
MENU LABEL ^12 Floppy Image 50 MB
kernel memdisk c=24 h=64 s=32 floppy
append initrd=fd050000.ima

the number c is supposed ramdom.
Well, Windows 98 seems want to boot.
I can see the windows logo when it loads.

The files are missed, so after logo there is message.



Instead Freedos stop with a message

Freedos FAT Kernel



I use VMware 6, it supports superfloppy

the number c is supposed ramdom.

Hmmm, more than "random" I would say "wrong":
Given that the filesize is 57,544,192, when you export it from Winimage adding a MBR it becomes 57,671,680 bytes


57,671,680/512=112,640 Sectors
112,640/32=3,520 Heads
3,520/64=55 Cylinders

55x64x32x512=57,671,680

So, I would try with a "c" of 55.

FreeDos is known to be a bit "picky" at booting, and the files in the image are a VERY old release.

Most probably the bootdisk of Windows 98 you used is an "install" disk, that, if I remember correctly, has hardcoded paths to A:, but using a HD image, the boot drive becomes C: .

Try using the image linked to here:
http://www.boot-land...?...ic=3121&hl=
(it is a self-extracting Winimage file, that you can open within winimage)

You should boot in VMware with BOTH the floppy image (booting the VM from it) and the Hard Disk image, and then issue a

sys a: c:

command.

jaclaz

I have tried 6.22 DOS Image and it works great.
So I have changed format: from 1.44 to 2.88 MB and it works.
My problem is how I can create images greater than 2.88 MB?

After I typed command you said before. It seem that c don't exist

here the result

Maybe we need a "re-do from start" approach.

I could well give you a "standard reply #32":
http://www.boot-land...?...c=2587&st=1

but I really have not time to search for my tarots.

If you do not post EXACTLY:
WHICH image you are using (among those downloadable from the BCDW site)
WHICH modifications you made/want to make with Winimage (or any other program)
WHAT you are trying to achieve

It is really impossible for me to help you.

If I can understand properly what you did, and if you follow my suggestions, maybe we can get somewhere, up to now:
1) You said you were using a 11.52 image.
2) But I had to find out that you were using a 50 Mb one.
3) You reported it did not boot, but that booted with Win98 without telling which source floppy image for Win98 you used and which procedure you used to make the downloaded from BCDW site image bootable.
4) I suggested to try making it a HD one.
5) I had to guess which image you were using and suggested you to use a Win98 floppy image I provided you a link for.
6) Accordingly to the above latter two steps, I suggested the procedure to make the HD image bootable with Win 98 files

From what you reported lately you:
a. did not try making the image a HD one
b. did not use the suggested floppy image
c. got a DOS 6.22 1,44 floppy image from somewhere
d. made it 2,88 (why? )
e. used the command I suggested, which resulted in a failure, rather obviously since if you did not change the image to HD like, it will never get a C:\ drive letter, maybe, just maybe, it is B:\ (second floppy)

You might want to read point f. of the "Common sense advice" in Rules:
http://www.boot-land...?act=boardrules]
and act accordingly.

back to the question:

My problem is how I can create images greater than 2.88 MB?

There are two possible answers:
#1. you type some random numbers in Winimage "Change format ->Select Custom Image format -> Edit FAT image size" edit boxes, until, by pure chance, you get a working image the size you want it
#2. you spend a little time trying to learn how images are set/can be calculated, which brings you straight back to:
http://www.boot-land...?...c=3100&st=3


my guess is that answer #1 requires very little attention but lots of time, whilst #2 requires lots of attention and a surprisingly small amount of time.

....decisions....always decisions....



jaclaz

Thx you jaclaz for your help.

I cannot summarize what I did, it will be too long.

Now I'm studyng cylinders, heads and sectors.

My goal is create a memdisk image largest than 2.88 MB
For images larger than 2.88 memdisk supposed it's hard disk image with MBR and partition table.

I'm trying to create a DOSEMU hard disk image so it isn't necessary specify CHS geometry during boot because memdisk give them from image (see here).

I'd like to write a tutorial about how convert a bootable dos based iso file to image compatible with memdisk.

Thx for your precious advices.

Yes, it is possible to make floppy images larger than that, like the ones on the BCDW site, but you will need to give the exact parameters.

The "limit" of autodected floppy size is 3840K, though.

Here you can find geometries for some of the common ones:
http://www.911cd.net...o...c=11096&hl=
http://www.911cd.net...o...c=10853&hl=


jaclaz

@romsempire and jaclaz

For your information, I tried the 11520 MB floppy image and it works with grub4dos by using floppy mapping,
but not with kernel/ramdisk technique:

title fd11520 (fd mapping, OK)

find --set-root /images/fd011520.ima

map --mem /images/fd011520.ima (fd0)

map --hook

chainloader (fd0)+1

rootnoverify (fd0)

 

title fd11520 (memdisk, hang after FreeDos string)

find --set-root /images/fd011520.ima

kernel /images/memdisk

initrd /images/fd011520.ima

Yes, as CLEARLY stated in the documentation, memdisk needs to have the CHS geometry of the image passed for images bigger than 3,932,160 AND the "floppy" parameter:
http://syslinux.zytor.com/memdisk.php

You need to invoke memdisk with something like:

kernel /bootdir/memdisk.gz c=80 h=2 s=18 floppy
initrd /bootdir/image.zip

I never used memdisk with parameters, so I am not sure if it works this way.

jaclaz

Yes, as CLEARLY stated in the documentation, memdisk needs to have the CHS geometry of the image passed for images bigger than 3,932,160 AND the "floppy" parameter:
http://syslinux.zytor.com/memdisk.php

You need to invoke memdisk with something like:
I never used memdisk with parameters, so I am not sure if it works this way.

jaclaz

OK I learn something new. Also I believe that the advantage using memdisk is that it accepts compressed (gzip) image, which
saves space (while floppy mapping method does not support compressed image).

Question: given a compressed (or non-compressed) diskette image, does your mbrbatch.cmd produces the CHS geometry? (although there is no MBR for floppy). This would be useful, to provide to memdisk correct values. The ima file will be produced without CHS knowledge by just using mksparse with
desired diskette size, than use ImDisk to mount it as floppy and format it.

Question: given a compressed (or non-compressed) diskette image, does your mbrbatch.cmd produces the CHS geometry? (although there is no MBR for floppy). This would be useful, to provide to memdisk correct values. The ima file will be produced without CHS knowledge by just using mksparse with
desired diskette size, than use ImDisk to mount it as floppy and format it.

Well, no, the point AFAIK is ALL in the way FORMAT under Win2K/XP works.

In the case of using FORMAT on a "HD-like" image, FORMAT will read the partition data and format the volume according to it's data (hidden sectors and size) BUT it will use, UNLESS the image is mounted with VDK from a .pln descriptor file, the default geometry of VDK (64/32).

IMDISK, on the other hand, can only mount a partition within the image, if you give the proper amount of offset (hidden sectors).

This way FORMAT has NO way to know what you want and just "guesses" some data:
hidden sectors will be 1
Heads and Sectors number will vary depending on size of the image.

For very small images, like floppy or superfloppy ones up to a few megs, FORMAT "guesses" geometry correctly, but for bigger ones, it may not.

MBRbatch, dealing exclusively with MBR's is not (and will never be) able to modify this.

Once and when MBRbatch will be complete and tested, I am planning to write a similar utility for bootsectors, which will probably be able to manage this aspect, or at least by creating a batch to run it with increasing values, to produce tabular data of the various geometries and sizes FORMAT assigns.

jaclaz

What I would do is a bit more difficult at first, i.e. creating the image and mounting it in VDK with a given geometry (it is not actually difficult, but needs a little of accuracy), the procedure is explained here:
http://www.911cd.net...o...19056&st=49
(but do read a few posts before too)

The above applies to a HD image, i.e. one that has MBR+Hidden sectors, search on the same thread for other ways to make a filedisk image (a partition only or "superfloppy" image).

For this latter type of image you can also use Imdisk.

jaclaz

@jaclaz
I desperately searching the mentioned topic (and others) to create customed superfloppy but did not find anything. Could you please point me to the
right topic/post ? Thanks.

@jaclaz
I desperately searching the mentioned topic (and others) to create customed superfloppy but did not find anything. Could you please point me to the
right topic/post ? Thanks.

This one by dennis123123:
http://www.911cd.net...o...19056&st=29
explains how to use filedisk to create a superfloppy type image, and previously I gave a link on 911CD Forum for common small superfloppy sizes.

But as said the problem with superfloppies is that one does not know, until an image is formatted, wich geometry the FORMAT command (or it's equivalent command under different OS or utility) will use for that specific size, nor if the same geometry will be used by the BIOS of the "Real" or "virtual" machine when booting.

Whilst this geometry is "standard" for 1,44Mb and 2,88Mb sizes, i.e. those corresponding to "Real" floppies, all other images can have geometries that may be valid for the format command and for other OS uses, but not "understood" correctly at boot time.

jaclaz