[syslinux] MEMDISK El Torito Emulation

[Shao Miller]

Bernd Blaauw wrote:
>
> And DOS so far requires the closed-source "eltorito.sys" driver from
> http://www.nu2.nu/eltorito/
>
Bart Lagerweij (of BartPE, for example) was kind enough to share the 
source for ElTorito.sys with us.  Unfortunately, it was slightly older 
than the most recent version of the driver.  It's simply fantastic that 
he shared it!

As far as "DOS so far requires" goes, this is only if you wish to access 
the .ISO RAM disk from DOS.  If you are simply booting an .ISO which 
itself boots a self-contained floppy or HDD image, then you don't need 
this driver.
>
> Any idea if the ReactOS CD or a (QEMU? Bochs?) emulated harddisk would
> work with Memdisk-ISO?
>
As mentioned elsewhere in this thread (on Friday), an OS like Windows, 
Linux, or ReactOS needs an OS driver to use a MEMDISK.  So the answer is 
yes and no...  Yes, MEMDISK will boot a ReactOS live CD image.  No, 
ReactOS will not find and use the RAM disk without a driver.  If the 
ReactOS live CD _itself_ loads a RAM disk and does not require a CD 
after that point, then you will have success.  As in, if you actually 
booted a physical CD to ReactOS and are able to remove that CD during 
the boot process, then ReactOS must be using its own RAM disk logic, 
regardless of MEMDISK or any other boot method.  I doubt this is the case.

A Windows driver which will currently find MEMDISK HDD images is 
WinVBlock, as Gert mentioned.  I've had one negative report for ReactOS, 
which isn't really that surprising, since ReactOS != Windows.  It would 
be great if you could test it, though!
>
> To go offtopic: can the Syslinux binaries be compressed? UPX
> (upx.sf.net, executable files compressor) chokes on it at least.
>
I just tried compressing and then decompressing the DOS SYSLINUX.COM 
with UPX and had success.

- Shao Miller