Hi, John,
Kevin Chen wrote:
> Does anyone see compilation CFLAG problem when
Microblaze hard
> multiplier is turned off?
What's the error message from GCC?
Kevin] There is no error message, it always use -mno-xl-soft-mul,
even when the hardware multiplier is turned off.
> The CFLAG still use the option for hard
multipler.
The logic in config.arch and Rules.mak in intended to
reflect that
MicroBlaze automatically uses HW multipler on V2, V4
and S3 families.
It also sets it if the USE_HW_MUL option is set on the
CPU.
This is a mess, and we've cleaned up for the next
petalinux release.
Kevin] In my design, Spartan3
is used and USE_HW_MUL is set to zero
> I’ve attached the fix. The files’
path follow
>
>
petalinux-dist/linux-2.4.x/arch/microblaze/platform/Rules.make
>
>
petalinux-dist/vendors/config/microblaze/config.arch
> Any comment or other way to fix?
The concern I have with your change is that, in my
understanding and
experience, with MicroBlaze v4.00 at least, EDK
ignores you if you set
USE_HW_MUL=
family.
Kevin] The design uses Microblaze
v4.00b in Spartan3E device, USE_HW_MUL is set to
I don't remember seeing anywhere on a single page, a
complete overview
of HW multiplier instantiation logic for the full
range of FPGA families
and CPU versions, with and without the USE_HW_MUL
parameter. If you can
find such a thing, let me know and we'll fix the
Makefile rules to obey
it! :)
Kevin] In Microblaze
Processor Reference Guide. UG081 v6.3 (doc in EDK
Best Regards,
-
Kevin