Re: [microblaze-uclinux] CONFIG_REGISTER_TASK_PTR

[Yasushi SHOJI <yashi@xxxxxxxxxxxxxxxxx>]

Hi John,

At Wed, 31 Mar 2004 12:02:08 +1000,
John Williams wrote:
[...]
> Long version - it's a hangover from the v850 origins of the microblaze 
> port.  the v850 port (and some others?) dedicates a register to hold the 
> current task pointer, to save the kernel a memory lookup every time it 
> needs it.    At the time I was porting entry.S, I couldn't get it to 
> behave, so moved over to the memory-based version.  I left the register 
> stuff in there for no particularly good reason.
> 
> There are some much easier targets for performance improvement, but if 

a bit off topic, but if you have time (I know, I know), it'd be nice
to have TODO list or stuff-you-want-to-fix list somewhere.

my current list, if i may:

- fix and move boot memory allocator code to arch/microblaze/mm/init.c
  this is half done here. no support for initrd and discon mem. we can
  now cat linux.bin romfs.bin > image.bin to create bootable image.

- toolchain

- 2.6 ;)

> you're keen, you could probably get it going.  I think I chose r31, so 
> you'd add "CFLAGS +=-ffixed-r31" into arch/microblaze/Makefile, to tell 
> mb-gcc that r31 is no longer available.
>
> Then find where we declare the "current" variable (I think in 
> arch/microblaze/kernel/process.c?), put some #define's around that, and 
> so on.

i've done upto there.  but still not working. :< I'll look into a bit more.

Thanks,
--
       yashi
___________________________
microblaze-uclinux mailing list
microblaze-uclinux@itee.uq.edu.au
Project Home Page : http://www.itee.uq.edu.au/~jwilliams/mblaze-uclinux
Mailing List Archive : http://www.itee.uq.edu.au/~listarch/microblaze-uclinux/