Charles,
in message DF2B720CF774D21189EE00805FA7FA220B909B67@nmrusdunsx3.nielsenmedia.com you wrote:
What's so complicated about this? See for example how Abatron ships their BDI2000s - they include a free TFTP server on their floppy disks which is so simple that even a Windoze user can start it.
You're making assumptions here that I don't believe are appropriate:
It is your assumption that I make assumptions, or maybe my lack of skill of the English language, which is not my native language. In any case, I was just trying to suggest alternative solutions.
- You are assuming that Brian's customers are at least as sophisticated as
Abatron customers. Brian's original statement leads me to believe this is not so.
Indeed I think they are. Typing "tftpsrv" (or which other ways there are to start the supplied application "tftpsrv.exe") is IMHO no a big challenge. And this is all you need to do.
- You are assuming that you know more about Brian's customers than either
he or his Marketing group does. Ultimately, it is the responsibility of a company's Marketing group to determine what a customer is capable of and will tolerate.
I don't think I gave any indication of such assumptions.
No, it is not. You are trying to re-invent the wheel.
This is certainly an emphatic statement. The least you could have done here is to prefix it with "IMHO".
Then I will have to prefix all my statements that way. Of course _everything_ I write is just my opinion. Sometime MHO, sometimes MNSHO.
U-boot supports the target-as-client method of downloading but does not support the target-as-server method. I've used both methods a number of times over the years and both have their advantages and disadvantages. Your
Can you please explain the advantages of the boot loader providing server function?
position seems to be that u-boot does everything useful for downloading. Therefore, if u-boot doesn't "do it", then "it" must be a duplication. I disagree. IMHO, target-as-server boot loading is a good idea. The two methods are useful in different circumstances and are not, IMHO, a reinvention.
At the company I work for, we have three different MPC850 designs that work together to form our new system. The boot code in all three units contains a target-as-server (UDP over Ethernet) loader. We use this UDP/Ethernet boot loader in exactly the mode that Brian is referring to above. It
Did you use any standard download protocol, like TFTP, or did you implement your own proprietary download protocol? Maybe you had to implement your own upload tool, too? If so, I see no real advantage of starting your upload application or starting a TFTP server application. IMHO, of course.
The way I see it, one of the benefits of these lists is discussion. To cut off discussion as you did is, IMHO, not productive.
OK, so let's discuss a little of U-Boot design philosophy - as I see it. YMMV.
U-Boot is a Boot Loader, not an OS.
U-Boot shall be powerful to use, yet simple in design to make it easily portable to new boards and architectures.
This means U-Boot will be strictly single-tasking; it will not use virtual memory; it will use polling drivers (versus interrupt driven ones) whenever possible.
U-Boot shall use standard protocols and interfaces whenever possible.
If you implement a TFTP server function within U-Boot, this will block until it's finished (probably after a succesful upload?). OK, you can use a canned command sequence to accept an upload and then start the uploaded image.
But the same can be done when using TFTP on U-Boot.
And if - for example during development - interactive operation is required or wanted, you will have to type to _one_ interface only (U-Boot). Otherwise you have to switch between U-Boot (start server function), host (run upload client), and back to U-Boot (start image or so).
I'm sorry, but IMHO there is no advantage running a server in the boot loader.
Perhaps you might be so kind as to elucidate.
[There _is_ some use for server-like functions in U-Boot: for example, many people have asked why U-Boot does not reply to ICMP messages (ping requests). There is no doubt that this would be a nice feature. On the other hand, think what it needs: you will have to always enable the network interface(s), you will have to deal with situations like when MAC addresses and/or IP addresses are not set, and you will have to deal with incoming network packets at any time - this would make the U-Boot design much more complicated. It _is_ a nice feature, but not worth the effort. IMHO.]
Best regards,
Wolfgang Denk