PXE details

Essentially correct, although you glossed over the details in the third point. PXE specifies what's in the fetched image and how it is loaded and activated. You create it just so that it contains a bootable sector, and a initial RAMdisk image.

Ah, so PXE shoehorns under the traditional BIOS, in a sense (i.e., wants the BIOS to think it has just read the boot sector off a *real* disk)?

Does it *enforce* this? Or, does it hand-off to some BIOS function that *expects* this?

Thx,

--don

I'm not sure if I understand what you are asking. You need both the traditional BIOS (to initialize the CPU/chipset/memory/peripherals) and the PXE BIOS (to do the networking magic). The details may vary; I think the most common case is that the PXE part is just another code path in the BIOS functionally equivalent to the disk boot sector reading code. The complication in PXE is that it has an elaborate fallback scheme for fetching the boot image, from the most specific image pathname constructed with the specific MAC address of the target to less and less specific ones.

Yes, I'm not worried about the BIOS/PXE part of the thing. That's all in place already.

Rather, my recent question was regarding what (if any) constraints PXE imposes on the actual *image* that it fetches. For example, it *could* want the image to look like a DOS executable (I am not claiming that is the case) with the appropriate signatures, etc.

Or, it could just expect a checksum (which it verifies?) and then it *trustingly* "jumps" to the first instruction expected to reside at the load location, etc.

In other words, do I have to do anything special to

Your earlier description seemed to suggest that.

Ah, that's not a problem -- many X Terminals have similar contortions.

In this case, I will control *all* of the images available so I can force a particular node to fetch a particular image.