[linuxsh-dev] Re: [linux-sh:01218] GDB configuration?

[Bryan R. <br...@ix...>]

NIIBE Yutaka wrote:

> Umm... how about setting of reflesh rate of BSC?  Is the RAM stable?
> I have experience that when I had problem of setting BSC, I had seen
> such unexpected error.
> --

I spent several hours last night debugging my system and have found
extremely strange problems with the string handling in the stub code. I
ran through dozens of test cases, slightly modifying the code each time,
and what I've found is basically unexplainable:

* Passing string pointers to functions is either broken, or buggy
* The order in which I set bytes in an array affects the end state of
the array

For example,

if I do something like:

foobuff[0]='F';
foobuff[1]='O';
foobuff[2]='O';
foobuff[3]=0;

Then call putpacket(foobuff) the output string is garbled ("F F" maybe);
however if I set byte 1, then byte 0, then byte 2, then byte 3, the
output is fine ("FOO"). There are other mysterious problems similar to
this, such as all the major string routines being broken (mem2hex, etc).

I can think of just two ways of explaining these problems--a really
buggy, broken compiler (which is not the case, I checked the assembly
output) or a problem with the hardware. Since string handling is the
most memory intensive task in the code I think my problems are just the
result of a nasty misconfigured hardware register. I will go back and
verify all of the BSC settings against our internal boot code and the
Hitachi data sheet and hopefully get things running today.

Thanks to everyone for their help,

Bryan Rittmeyer
mailto:br...@ix...