Backup DELL GX280 BIOS and hack it?

[swartz]

Got a few Dell GX280 desktop computers used as test environment. I use free VMware ESXi server on them to test various pieces of software/OSs.
The annoying part is that ESXi keeps displaying error message that allude to CPUIDLimit is being limited. And recommends to disable this feature in BIOS. However Dell bios has no such settings.

Is there a way to add this setting?

Here's the latest bios from Dell:
ftp://ftp.us.dell.com/bios/GX280A08.EXE


Also these machines support upto 4Gb (4x 1Gb) of RAM (according to DELL), which they are equipped with. However none of the OSs I've tried, including Win XP/Vista 32bit (with and without PAE), XP/Vista x64, Ubuntu 32bit/x64 can see all 4gb. Regardless of what OS tried, they only see 3.1Gb of it. BIOS reports that it sees full 4GB.

After doing some research, Memory Hole (aka memory remap, memory hoist) setting may need to be enabled to let them OS's see the memory above 4gb. However, Dell BIOS once again does not have this option.

Can this also be added?

I've tried playing with modbin. However Dell does not provide .bin of their BIOS. I've tried extracting the .rom file from the above exe via
GX280A08.EXE -writeromfile

But modbin can't open it saying it isn't version 6.0.

Is there a way to back up current GX280 bios? From DOS?

Any suggestions would be most welcome!

[bgavin]

Re: Backup DELL GX280 BIOS and hack it?

Modbin has to run from a genuine DOS bootup.
I keep an MS-DOS 6.22 boot cd for just this purpose.
It installs a RAMDRIVE to use as the hard disk.

Modbin works fine here.
Dunno if it will disassemble your Dell bios or not.

If the Dell BIOS is indeed limiting the Intel processor, there will be code in the bios to do so. You will have to dig that out. I hope you speak ASM. You can disassemble it under DEBUG and look for writes to the Intel specific ports.

[swartz]

Re: Backup DELL GX280 BIOS and hack it?

Are you saying that MODBIN can edit live BIOS?

I was hoping to dump the BIOS first and then try to edit it with modbin.
Only then attempt to flash it.

[Wizard]

Re: Backup DELL GX280 BIOS and hack it?

2 reasons for the CPU limiting and memory loss.

1. CPU limit have many reasons: chipsets that is too old or limited on purpose so forces lesser CPUs used. Particularly true like the ZX, LX and VX of old, and 810, 815 etc. And still applies to P4. This SFF system if I assume is limited for heat concerns and not to compete with higher end system by blocking VT for example by way of specifiying max CPU types for example. This was really common in IBM back then as IBM was after reliability and had a habit of iron fist on what machines are should be intended to be. Basically pay up more for what you need more features. Way out back then was build your own and still is.

2. 3.1GB is because this SX280 is not marketed as particular market like you are attempting to do so trying it as server which is not good idea on a limited PC. Look for different systems or build your own using Asus board for example due to fewer limits.

CAUTION! modbin was created for award bios for older boards (pre 2003). I'm not aware of newer bios editors out there for athlon, P4 and later.

Cheers, Wizard

[swartz]

Re: Backup DELL GX280 BIOS and hack it?

GX280 are based on i915 chipset.
CPUID Limit is enforced so that these systems are compatible with pre-WinXP OS's.
I have seen other mobo's on i915 with CPUID Limit option in BIOS.
I think this is a case of DELL being lazy.

When the systems were originally bought, DELL marketed GX280 as supporting the full 4GB. This was very misleading. DELL should be ashamed knowing that the most customer will see is 3.1Gb. I realize if I had a 32bit OS, 3.1GB is a technical limit there. Again I think this is something that could be enabled via BIOS to just remap the extra 1Gb into over 4GB range.

Yes, I realize I'm trying to push the hardware beyond what it was marketed for. CPUID Limit seems like an easy task to add. Its just a register bit change.

Originally systems came with 1x 512Mb DDR2. After stocking on 2GB DDR2 sticks, we found out that full 4GB will not be available. So I improvised and swapped memory for 2x1GB plus 2x512Mb instead of 4x1Gb like we originally planned to have. Good thing there are 4 ram slots. So I (we) can live with 3Gb. However, if there is a chance to enable memory remapping that would be awesome! Maybe these things can support 8Gb? Highly unlikely I know.

[ratdude747]

Re: Backup DELL GX280 BIOS and hack it?

lesson: nevr buy OEM:

Only stuff you can use is what we give you
Employees in tech support no speak english or even engrish
Money is what is needed to fix your problem, money for a new system

thats how i view brand-new oem towers. laptops are another story.

[Topcat]

Re: Backup DELL GX280 BIOS and hack it?

Shove a 64 bit CPU in it and run X64, it will see all of your RAM then. X32 will only see 3gb or so. That's not the fault of the system, its the OS. If the BIOS is reading all 4GB, but the OS isnt, its time to move to a 64 bit setup. As far as the BIOS, I've never tried hacking a Dell BIOS, so I can't help you there.

Nothing wrong with an OEM system if you don't plan on doing anything out of the ordinary with it. They're great daily use systems, but I'd certainly never build a gaming rig around one...

[swartz]

Re: Backup DELL GX280 BIOS and hack it?

Shove a 64 bit CPU in it and run X64, it will see all of your RAM then. X32 will only see 3gb or so. That's not the fault of the system, its the OS. If the BIOS is reading all 4GB, but the OS isnt, its time to move to a 64 bit setup. As far as the BIOS, I've never tried hacking a Dell BIOS, so I can't help you there.

Nothing wrong with an OEM system if you don't plan on doing anything out of the ordinary with it. They're great daily use systems, but I'd certainly never build a gaming rig around one...

I have tried putting Vista x64, Ubuntu x64 on it. It still only sees 3.1Gb of it.
My research indicates that memory above 3.1Gb is reserved for IO devices (PCI, PCIe). BIOS must provide memory remapping option for the remainder of memory to show up in 64bit (or 32bit with PAE) OS. DELL's bios in GX280 does not have memory remapping switch anywhere in BIOS. Hence why I'm looking for a hacked BIOS or tools that would allow me to modify it.

[Per Hansson]

Re: Backup DELL GX280 BIOS and hack it?

As far as I know the Dell's use some properiatry Phoenix BIOS
I have tried to find something that can edit the Precision 470 but run into the same issue as you have...

http://forums.mydigitallife.info/showthread.php?p=75149

[bgavin]

Re: Backup DELL GX280 BIOS and hack it?

I have a bunch of DL380-G5 servers running 8gb and 32-bit Server 2003 with PAE. Dunno if XP will do this or not. Other than video editing, I've not found much need for > 3.4gb real memory. This is the available limit under XP in most cases.

My experience with Modbin is that is reads the bios, makes a backup dump then lets your work on the image file. Once edited to your satisfaction, the image is uploaded back to the BIOS.

Modbin is an old program and may not under the new, larger BIOS. YMMV.

My take is "why bother."

[swartz]

Re: Backup DELL GX280 BIOS and hack it?

I have a bunch of DL380-G5 servers running 8gb and 32-bit Server 2003 with PAE. Dunno if XP will do this or not. Other than video editing, I've not found much need for > 3.4gb real memory. This is the available limit under XP in most cases.

My experience with Modbin is that is reads the bios, makes a backup dump then lets your work on the image file. Once edited to your satisfaction, the image is uploaded back to the BIOS.

Modbin is an old program and may not under the new, larger BIOS. YMMV.

My take is "why bother."

We use the GX280s for VMware's ESXi servers as testing environments for various software and OS's. So 3GB is bordering on hindering performance especially if a whole bunch of OSs are booted and running for testing.
Unfortunately GX280s are low-end consumer PCs and DELL purposely limits its upgrade paths.

[swartz]

Re: Backup DELL GX280 BIOS and hack it?

I have a bunch of DL380-G5 servers running 8gb and 32-bit Server 2003 with PAE. Dunno if XP will do this or not. Other than video editing, I've not found much need for > 3.4gb real memory. This is the available limit under XP in most cases.

My take is "why bother."

We use the GX280s for VMware's ESXi servers as testing environments for various software and OS's. So 3GB is bordering on hindering performance especially if a whole bunch of OSs are booted and running for testing. 1GB extra is not much, but it would come in handy.

Unfortunately, I realize, GX280s are low-end consumer PCs and DELL purposely limits its upgrade paths.

My biggest gripe is that when these were purchased by the university that employs me (way before I started), these GX280's were marketed as having support for full 4Gb of RAM. So when the time came to upgrade (these originally only had 512Mb), we got a nasty surprise.

I'm happy to say that university is contracting local shops to buy new computers in bulk as oppose to buying from DELL and other big companies which limit the upgrade paths or cut support earlier to force you to upgrade.
This makes it harder to support since instead of 1000 of identical boxes, we now have a few groups of 100 or so PCs, with each group being a different PC. But for the most part this has improved our computer support as we can talk to local techs directly as oppose to having to talk to DELL India to have anything resolved.

However as computers in libraries, classrooms, and major offices get upgraded to newer ones, these GX280's are being redirected to labs, grad student offices (some still have PIII boxes to date) and etc. So when a "decommissioned" GX280 comes in, we make them useful once again by upgrading CPUs, RAM, and HDs and put them out for further use. Hence why we have close to 20 of these GX280's in our lab at any given moment.

PS. Stupid 10min limit

[swartz]

Re: Backup DELL GX280 BIOS and hack it?

lesson: nevr buy OEM:

Only stuff you can use is what we give you
Employees in tech support no speak english or even engrish
Money is what is needed to fix your problem, money for a new system

thats how i view brand-new oem towers. laptops are another story.

Unfortunately buying from OEM has both cons and pros. Like everything in life, I guess/
Pros:
I have always have spare parts.
Upgrading and maintaining is easier.
Tech are familiar how to quickly open and fix some common problems.

However, if there is a serious issue and need to phone in... thats quite the experience. DELL's business support was good and we could actually get someone who spoke perfect engrish and was actually capable of analyzing our problems.. Recently when I inquired about this BIOS upgrade for things like memory remapping, and CPUID... I got just another DELL India call center slave... who, lets put it lightly, didn't know his arse from his elbow.

[bgavin]

Re: Backup DELL GX280 BIOS and hack it?

these GX280's were marketed as having support for full 4Gb of RAM.

They do have support for the full 4gb of ram.
Their 32-bit addressing registers can indeed address every last bit of that 4gb.

Windows commandeers some 600mb of that address space for system use.
The ROM BIOS, video BIOS, and so forth have to live somewhere...

You will find that 3.4gb of usable is typical in a 4gb Windows system.
The GX-280 is a four slot RAM configuration.
Each slot will accept a DDR2 1gb or smaller stick.
This is the hardware limitation of the machine, so you are stuck with 4gb.

[gg1978]

Re: Backup DELL GX280 BIOS and hack it?

The 915 chipset doesn't support remapping memory over the PCI address range.. So even if you did successfully hack the BIOS to remap the memory, the i915 northbridge won't do it still leaving you with less than 4Gigs... Even if you put a 64bit OS on there, or a 32bit one that supports PAE you will NOT get access to all 4 Gigs.. I don't think even the later i945 could remap over 4Gigs either.. I think i965 on up do though...

It's not a limitation exclusive to dell.. If you want to bitch about it, blame Intel..

[gg1978]

Re: Backup DELL GX280 BIOS and hack it?

Well, i've just found out something interesting about the i915 chipset, after i downloaded its datasheet from ark.intel.com.. If you go by what ark.intel.com says, supposedly i915 can actually address 8Gigabytes of RAM.. Here's the kicker though, if you actually download the i915 series datasheet, it also says it can address up to 8Gigabytes of Memory.. Here's the thing though, on page 26, towards the bottom.

The (G)MCH supports 32 bit addressing, decoding up to 4GB of the processor's memory address space.. Host-initiated I/O cycles are decoded to Pci Express, DMI, or the (G)MCH.

So there it is.. The chipset can actually address 8GB, but only gives the processor access to 4GB, less what the PCI, PCI express, DMI, etc take away..

I'm curious now.. I'm going to grab the i945 and i965 datasheets, and see what extra gubbins the i965 has in order to actually address and use 4Gigs or more of memory..

[swartz]

Re: Backup DELL GX280 BIOS and hack it?

So there it is.. The chipset can actually address 8GB, but only gives the processor access to 4GB, less what the PCI, PCI express, DMI, etc take away..

Interesting find. Thanx for the FYI.

I'd still like to punch that DELL person that sold us these GX280's and claimed that full 4Gb is in fact supported. And by "supported" I mean usable by OSs/applications.

I did some research of my own. The reason we only see 3.1Gb is because these GX280 have PCIe, which reserves a whole 512Mb chunk of address space additional to a typical 32bit reservation space.

So we wont even see 3.5Gb due to PCIe on the motherboard. But, like I said, we got used to 3Gb limit now. Still, however, that CPUID Limit flag would be nice to disable. So far I have found no way to do so.

Dell officially no longer provides BIOS updates for this series of desktops... well, duh, of course.

[Wizard]

Re: Backup DELL GX280 BIOS and hack it?

Don't punch the Dell. That's NORMAL for big chunk of space taken away depending on board design. *Especially* with OEM. If going with build your own PC, can see anywhere from 3.1 to 3.5GB. Once you are in 8GB with 64bit OSes with DIY PCs and decent models of OEM PCs, then things will work.

Cheers, Wizard

[ratdude747]

Re: Backup DELL GX280 BIOS and hack it?

Nothing wrong with an OEM system if you don't plan on doing anything out of the ordinary with it. They're great daily use systems, but I'd certainly never build a gaming rig around one...

oem means you get less for more

[Wizard]

Re: Backup DELL GX280 BIOS and hack it?

oem means you get less for more

Exactly to both Topcat's and ratdude747's. This is PERFECT use especially in business use. Like I have this 8300 on my bench and Netvista (boss's pc that I bought cheaply for his use) here at work no more or less. But eventually both will get replaced, for example 8300 will be boss's and I upgrade to phenom II 550 stuff since I'm very heavy on PDF and other stuff and boss's is still on PIII 866 box and once in awhile couldn't do anything on a certain website.

That was same reason I had to replace ailing compaq, no badcaps (UCC and Rubies) interestingly and cooling is GOOD with a Pentium Duo E2200 DIY PC using decent board (Asus). Stopped the annoyances (corruptions/crashes) and moved up from 98 to XP so stuff can go along easier for data transfers.

Cheers, Wizard