[ECOS] LX4180

[ECOS] LX4180

[Xavier Wang]

Hi,

I tried to build eCos for Lexra LX4180 which is a MIPS
R3000-like CPU. It seems to be a good start from building
GNU toolchains and eCos for Toshiba TX39. But I found
that TX39 seems to have instructions that are not in the
standard ISA I instruction set, such as Branch Likely and
ISA III cache instructions. So, is it possible to configure
GCC to generate only standard ISA I instructions?

Thanks.

-- Xavier

RE: [ECOS] LX4180

[Jurica Baricevic]

Xavier wrote:
> I tried to build eCos for Lexra LX4180 which is a MIPS
> R3000-like CPU. It seems to be a good start from building
> GNU toolchains and eCos for Toshiba TX39. But I found
> that TX39 seems to have instructions that are not in the
> standard ISA I instruction set, such as Branch Likely and
> ISA III cache instructions. So, is it possible to configure
> GCC to generate only standard ISA I instructions?

Probably the best solution would be to configure GCC to support your
specific processor architecture by default (i.e. I am using
'mipsel-r3041-elf-gcc'). There is also possibility to build GCC for any MIPS
ISA architecture ('mips-any-elf-gcc'). In that case, you should provide GCC
with some specific options (egg '-mcpu=r3000'), when building eCos.

Anyway, since you have intention to run eCos on a R3000 MIPS, you may have
some problems with a 'load delay slot'. Please, check the ecos-discuss
mailing list archive:
http://sources.redhat.com/ml/ecos-discuss/2000-06/msg00003.html
http://sources.redhat.com/ml/ecos-discuss/2000-06/msg00014.html
http://sources.redhat.com/ml/ecos-discuss/2000-06/msg00024.html

Regards,
Jura