[avr-libc-dev] Re: Iotn13.h

[Theodore A. Roth]

On Thu, 20 May 2004, Bruce Graham wrote:

> Ted,
>
> Here is my suggested patch for the header iotn13.h  I did not test it
> very well since I have been unable to run "avr-as" by itself
> successfully.  I seem to be short the right document, which I probably
> have but can't find, or less likely don't have and can't find.
>
> Some things may be controversial:
> (1) When there is no External Memory -- should XRAMEND be 0? or should
> it be equal to RAMEND.  Actually I could go either way and I can't see
> where the symbol is used -- probably in malloc.
> (2) Although PB5 is a handy shorthand, the tradition for bit names seems
> to be:
>     (a) use the data sheet name if a name is given
>     (b) concatenate numbers to the register name if a name is not given
> (3) I was not sure what SPEN referred to in register SPMCSR.  I could
> not find it in the data sheet, nor could I find it in one or two other
> data sheets I checked.  I hope it was just a mistake, but I could
> believe it came form an earlier version of the family.

Attached is what I committed (basically limited to comments only, but
with the fix for SPMEN).

A few notes about your original patch.

  - Please don't add lots of white space at the end of comments.
  - EEAR and EEARH don't need to be undef'd since they are handled by
    avr/io.h.
  - SP and SPL don't need to be undef'd either.

Now, I like the concept you introduced for setting _VECTORS_SIZE, but I
didn't include that change here since it should be done more globally. I
would rather see something like the following.

In avr/io.h:

  /* The value defined in the device io header for _MAX_VECTOR_NUMBER
     should be the highest number used in the SIG_* defines, while
     the value for _VECTOR_INSN_SIZE should be the size of the vector
     instruction in bytes. This will be either 2 (for devices that don't
     support the JMP instruction) or 4 (for devices that can use the JMP
     instruction). */
  #define _VECTORS_SIZE ((_MAX_VECTOR_NUMBER)+1)*_VECTOR_INSN_SIZE

Then in each io*.h file (using iotn13.h as example):

  #define _MAX_VECTOR_NUMBER  9
  #define _VECTOR_INSN_SIZE   2

One last thing about your usage of CVS. I think you are making it more
difficult than it needs to be. It looks like you are trying to work with
a local repository with your own tree structure or a repo for each file
you are working on. This is making it a bit more difficult for you to
generate patches and for me to apply those patches.

Here's the steps you need to take to generate a patch (as unix shell
commands, but it shouldn't be too hard to figure what to do for
windows).

Check out the cvs tree:

  $ cvs -z3 -d:ext:address@hidden:/cvsroot/avr-libc co avr-libc

Go into the tree:

  $ cd avr-libc

Edit files to your hearts content:

  $ vim include/avr/iotn13.h

When you are done editing, generate a patch:

  $ cvs diff -u > my-changes.diff

Look the diff file over and if it looks right, post it to the
avr-libc-dev list.

Notice that I generated the diff file from the top of the tree. This
allows me or anyone else to apply the patch like this:

  $ patch -p0 --dry-run < my-changes.diff

If the --dry-run doesn't spew a bunch of errors, I'll apply it:

  $ patch -p0 < my-changes.diff

Hope that helps.

---
Ted Roth
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