On 2018-02-24 17:21, Paul Koning wrote:


On Feb 23, 2018, at 8:52 PM, Johnny Billquist <b...@softjar.se> wrote:



On 2018-02-24 01:56, Paul Koning wrote:
On Feb 23, 2018, at 5:28 PM, Johnny Billquist <b...@softjar.se> wrote:

...
That's why a MOP load normally consists of asking for a program - which is the 
secondary loader.  It's the secondary (or tertiary) loader that knows how to 
unpack an image and make additional requests.

Hum. Well, that might be, but both will be served through MOP, so it don't make 
much difference if it's the primary or secondary boot. They are served the same 
way.
Almost.  A secondary loader response carries the entire secondary loader in a 
single message, so the bootstrap only needs to handle one message.  Tertiary 
and OS loads are expected to take multiple messages.

Yes. But what difference does that make on the server side? The fact that the 
requested image is small enough to fit into one frame is just a detail that 
makes the client implementation easier.

The difference is that the server is required to answer a request for secondary 
loaded with a single response packet holding the entire response.  For other 
loads, it can deliver the data in pieces, and the size of those pieces it its 
choice.  For the second loader, it does not have that choice.

The MOP servers I know of don't even know about that distinction. They just serve the image. If it fits in one frame, it will come in one frame. If it don't, it won't. The server can't do more than that.

  Johnny

--
Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: b...@softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol
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