On Mon, 2013-03-04 at 14:12 -0700, Jack Thomasson wrote: 
> On Sunday, 03 Mar 2013 11:33:42 Jeremy Bennett wrote:
> > 1. Could you update the documentation (in the doc folder) to match.
> 
> hmmm, i thought the changes i submitted for doc/or1ksim.texi were sufficient. 
>  what more do you want updated?

Hi Jack,

Apologies - I managed to miss a part of the patch when reviewing it.
These changes are fine, but could you add a small note about how
endianness is dealt with (along the lines you give below) - I can see
this being a possible cause of confusion.

What is missing is the ChangeLog entry. Could you add this.

> > 2. Could you supply a git patch if at all possible. The main repo is at
> > https://github.com/openrisc/or1ksim.
> 
> yep, can do.  i'll wait on the answer regarding the docs before submitting.

Docs will be fine with a note about endianness - look forward to the
patch.

> > One day the problem will go away, when we can drop the or32 branch.
> 
> so maybe i'll submit against just or1k to accelerate the process a tiny bit.

I'm not sure it accelerates things-:( But I'll don the merge into or32.
We're glad to have the patch in any form.

> > I have some questions/commentary on your code. You don't need to do
> > anything about these - it's just to help my understanding.
> > 
> > 1. peripheral/memory.c: I'm curious about the use of "seed" for the file
> > handle name. Personally I'd have defined a variable "fh" (or similar) to
> > avoid confusion.
> 
> i thought about adding another variable as well but realized the file
> is seeding the memory so it works. 
> 
> > 2. peripheral/memory.c: I'm not sure worrying about endianness is a good
> > thing here. I would be inclined to say that the file is just a byte
> > image, and it is up to the user to ensure the sequence of bytes matches
> > the endianness of the machine. It will mean the file can always be used
> > for other tools as a true image of memory for the particular machine. It
> > is trivial for a user to have an external utility to swap byte order to
> > create a new file if that is what they need.
> 
> if i seed memory with a file containing "AbCd" and use a simple
> program like the attached dumpROM.c, i expect to get "AbCd". on my
> x86_64-unknown-linux-gnu host without swabbing i get "dCbA". that will
> be confusing for users not familiar with endianness. we could send
> them haring off through the user manual and the file could be
> converted offline but it seems kinder to the user to do it for them. 
> 
> > 3. Is a straight binary file what you want? Had you considered
> > supporting the image formats used by Verilog $readmemh and $readmemb.
> > Maybe these should be further memory options, "readmemh" and "readmemb"
> > for the future.
> 
> well, to an old Un*x hacker, _ALL_ files are binary :{)}. my source
> data is a pcap file so definitely "straight binary". 
> 
> i am not that familiar with Verilog, barely learning VHDL right now to
> tell the truth, but i did look up these with Google and they are
> definitely not what i want. i agree they deserve to be implemented but
> i expect the endianness problem to show up here as well so better to
> have a correct implementation already coded in memory.c. 
> 
> :{)}

Thanks for all your work. I look forward to merging in the patch very
shortly.

Best wishes,


Jeremy

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