Syslinux - Oct 2002 - Does pxelinux work with >1GB RAM?

On machines with 2GB RAM, pxelinux doesn't seem to work for me. With
Intel PXE, I had to limit the memory available to PXE to 768MB RAM.
Has anyone tried pxelinux on machines with >= 1GB RAM? How do I
limit memory to 768MB for pxelinux?


H.J.

H. J. Lu wrote:
> On machines with 2GB RAM, pxelinux doesn't seem to work for me. With
> Intel PXE, I had to limit the memory available to PXE to 768MB RAM.
> Has anyone tried pxelinux on machines with >= 1GB RAM? How do I
> limit memory to 768MB for pxelinux?
> 
It had been run, successfully, on machines with as much as 6 GB of RAM.

	-hpa

On Mon, Oct 07, 2002 at 05:36:35PM -0700, H. Peter Anvin
wrote:
> H. J. Lu wrote:
> > 
> > Although it looks very ugly, moving buffers after the code makes
> > pxelinux to work with Promise BIOS.
> > 
> 
> I actually now remember an earlier bug report where it was also found
> the Promise BIOS scribble on memory it has no business using.
> 
I found the problem. Personally, I believe it is a bug in pxelinu. For
one thing, 0x500 to 0x7c00 is reserved in PXE 2.1 spec. However, it is
not the real problem. pxelinux has

		absolute 5000h          ; Here we keep our BSS stuff
			^^^^^^^^
			Why leaves a hole in memory?

VKernelBuf:     resb vk_size            ; "Current" vkernel 
                alignb 4
AppendBuf       resb max_cmd_len+1      ; append= 
KbdMap          resb 256                ; Keyboard map
BootFile        resb 256                ; Boot file from DHCP packet
PathPrefix      resb 256                ; Path prefix derived from the above
ConfigName      resb 256                ; Configuration file from DHCP option
FKeyName        resb 10*FILENAME_MAX    ; File names for F-key help
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This conflicts with Promose BIOS.

I will send you a patch soon.



H.J.