Re: [Oslib-devel] Re: makefile in examples directory?

[Bryce D. <br...@tl...>]

On Sun, 7 Oct 2001, luca abeni wrote:
> After unzipping the file, you will have to copy the correct mk/*.mk file in 
> config.mk, and do make install (make all will fail because it does not 
> install the libraries in the correct directory).
> That should produce all the .xtn files in the examples directory.

You're right...the makefile is there.  I was confused because of the
problem that you describe with make all, and then I was expecting a
makefile with a capital M so I didn't ever find it. :)  When I finally 
did make install, it worked.

[bryce@monster oslib]$ make
... lots of successful compiling ...
make[1]: Entering directory
`/usr/users/bryce/tlw/bochs/tstimg/oslib/oslib/examples'
make[1]: *** No rule to make target `mbdemo.xtn', needed by `all'.  Stop.

[bryce@monster oslib]$ make -C examples
make: Entering directory
`/usr/users/bryce/tlw/bochs/tstimg/oslib/oslib/examples'
make: *** No rule to make target `mbdemo.xtn', needed by `all'.  Stop.
make: Leaving directory
`/usr/users/bryce/tlw/bochs/tstimg/oslib/oslib/examples'

[bryce@monster oslib]$ make install
... some more compiling and linking ...
and it worked.

> Let me know if you have other problems.
> (Warning!!! Due to a known bug in oslib - I never had the time to fix it -, 
> the most recent versions of GRUB cannot be used... I am currently using 
> version 0.5.95)

It would be great if you can document this.  It was reported as a
potential bochs bug, and Sandro Magi and I spent quite a bit of time
yesterday wondering if bochs was simulating it right or not.  It seems
like the initial test for the a usable GDT is not good enough, and you
should just set up your own GDT every time.

 /* Test if GDT is usable */
  movl    %gs:0(%ebx),%ecx
  andl    $0x080,%ecx
  jnz     GDT_is_OK

With grub 0.90, it takes the branch and assumes the preexisting GDT is
usable, when in fact it's not.  The GDT limit is 0x27 and you use selector
0x30 (index 6) which is beyond the end of the GDT table.  See my analysis
at

http://sourceforge.net/tracker/index.php?func=detail&aid=468563&group_id=12580&atid=112580

> As a side note, I tried to run some oslib examples on bochs some time ago, 
> but my code uses some strange PIT modes that were not supported by bochs. I 
> see that the current version of bochs implements a more complete PIT model, 
> hence I will try it again, and I'll let you know the results.

Super!  Testing bochs with lots of little open-source examples is a great
way to get things fixed.  So many of our bug reports are problems that
occur millions of cycles into a windows boot or something, so it's nearly
impossible for us to reproduce the conditions exactly.  And in many cases,
it would be illegal for the user to send us disk images for debugging.  
Now that I know about oslib tests, I will probably use them for bochs vs
physical hardware testing as well.

Thanks a lot for your help!
Regards,
Bryce