[gPXE] 512MB Limitation of gPXE ?

[LinuxbyExamples]

Hi Shao,

Thanks very much for your reply. It look likes that I have miss-understand a lot thing :)

I call the image vhd because I did use VirtualBox to create the image (preallocated disk in vhd format). This is the term from virtualbox, I just call it as. 

I use grub4dos because in the image, winxp has been installed with a special driver called winVblock, and I am not sure if memdisk can work with this drivers ?!

The last thing, so there is no limitation about 512MB with gPXE ?! or I have to use memdisk to overcome this ?!

I will try memdisk and feedback soon. 

Brs.

On Oct 18, 2012, at 22:29, "Shao Miller" <sha0.miller at gmail.com> wrote:

> Good day, guy.
> 
> Your config-file LABEL doesn't seem right.  The LABEL should reflect the
> name of the item that you are booting.  You have already booted gpxelinux.0
> and it is gpxelinux.0 that reads the config-file, so "LABEL gpxelinux"
> doesn't make a lot of sense.  I'd suggest using "LABEL winxp", since that is
> what you are booting from gpxelinux.0.
> 
> Back to your problem, is there any reason why you are not using MEMDISK,
> instead of GRUB4DOS?  Please try it and see if there's any difference:
> 
>  LABEL winxp
>    KERNEL http://192.168.100.254/memdisk
>    INITRD http://192.168.100.254/MiniXP350.vhd
>    APPEND raw
> 
> Also note that "Later, grub.exe will map the vhd image into memory" is
> incorrect.  gpxelinux.0 is the program that maps the VHD into memory in your
> current scenario.  GRUB4DOS establishes a very simple mapping of BIOS drive
> 0x80 to the already-mapped VHD image.
> 
> Also: Why are you calling your image a VHD?  If it can be booted by GRUB4DOS
> in the way that you've described, the image is basically just a
> sector-by-sector disk image.  There's no need to confuse things by calling
> it a VHD.
> 
> - Shao Miller
> 
> ________________________________________
> From: gpxe-bounces at etherboot.org [mailto:gpxe-bounces at etherboot.org] On
> Behalf Of LinuxByExamples
> Sent: Thursday, October 18, 2012 09:04
> To: gpxe at etherboot.org
> Subject: [gPXE] 512MB Limitation of gPXE ?
> 
> Hi, 
> 
> This is the first time I use this mailing list, so I am very sorry if I have
> made any mistake.
> 
> Well, here is my case, I have followed this post
> : http://www.linuxbyexamples.net/2012/08/boot-winxp-from-http-server.html
> 
> _ I can use gPXE to download two files : grub.exe and winxp.vhd image by
> http. Later, grub.exe will map the vhd image into memory then successfully
> load the windows xp. The config file look this :
> 
> LABEL gpxelinux
> kernel http://192.168.100.254/grub.exe
> initrd http://192.168.100.254/MiniXP350.vhd
> APPEND --config-file="map (rd)+1 (hd0); map --hook; chainloader
> (hd0,0)/ntldr"
> 
> This works very well.
> 
> _ But when the winxp.vhd image becomes bigger than 512MB ( I added some more
> files and winxp modules into to the image), the loading step fire an error
> tell me that the image can not be loaded ... I then try put the bigger vhd
> image and grub.exe into usb disk and I can boot it well (without using gPXE
> http loading). So, I guess the problem is in gPXE module, it looks like that
> gPXE can not load the image bigger than 512MB ? is this right or I have
> missed something else ?
> 
> I hope you can help to overcome this limitation.
> 
> Thank you guy. 
>