[ECOS] Porting RedBoot to NEC V850 platform

[ECOS] Porting RedBoot to NEC V850 platform

[Stephan Eisvogel]

Hi all,

I'm in the process of putting eCos 2.xx onto the NEC startWARE V850/SA1
development board to evaluate its capabilities as a RTOS. Our lab has
so far been using MULTI2K from GHS and a NEC V850 ICE for development,
but we want to try out GNU together with RedBoot. I get to work on eCos
for the V850 as an internship project.

Now, I realize nobody has ported RedBoot to V850, and I'm willing to
do this myself, but I can't find documentation on how to go about this.
I'm also relatively new to eCos. I really could use maybe a top 10 list
of things that have to be done to get RedBoot over to V850, maybe one
of the long-time developers can help me here?

Thank you in advance,
Stephan

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Re: [ECOS] Porting RedBoot to NEC V850 platform

[Nick Garnett]

Stephan Eisvogel <eisvogsn@iis.fhg.de> writes:

> Hi all,
> 
> I'm in the process of putting eCos 2.xx onto the NEC startWARE V850/SA1
> development board to evaluate its capabilities as a RTOS. Our lab has
> so far been using MULTI2K from GHS and a NEC V850 ICE for development,
> but we want to try out GNU together with RedBoot. I get to work on eCos
> for the V850 as an internship project.
> 
> Now, I realize nobody has ported RedBoot to V850, and I'm willing to
> do this myself, but I can't find documentation on how to go about this.
> I'm also relatively new to eCos. I really could use maybe a top 10 list
> of things that have to be done to get RedBoot over to V850, maybe one
> of the long-time developers can help me here?
> 
> Thank you in advance,
> Stephan

The HAL porting guide should contain most of what you want to
know. The basic technique it advocates is to port RedBoot first, then
do eCos.

You can find it here:

http://sources.redhat.com/ecos/docs-latest/ref/hal-porting-guide.html


-- 
Nick Garnett                    eCos Kernel Architect
http://www.ecoscentric.com/     The eCos and RedBoot experts


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Re: [ECOS] Porting RedBoot to NEC V850 platform

[Jonathan Larmour]

Stephan Eisvogel wrote:
> Hi all,
> 
> I'm in the process of putting eCos 2.xx onto the NEC startWARE V850/SA1
> development board to evaluate its capabilities as a RTOS. Our lab has
> so far been using MULTI2K from GHS and a NEC V850 ICE for development,
> but we want to try out GNU together with RedBoot. I get to work on eCos
> for the V850 as an internship project.
> 
> Now, I realize nobody has ported RedBoot to V850, and I'm willing to
> do this myself, but I can't find documentation on how to go about this.
> I'm also relatively new to eCos. I really could use maybe a top 10 list
> of things that have to be done to get RedBoot over to V850, maybe one
> of the long-time developers can help me here?

To add to what Nick said, the reason RedBoot wasn't ported before was 
primarily because V850 targets tend to be memory constrained, and the V850 
isn't a particularly whizzy chip anyway. Certainly be aware of the former, 
depending on your target.

After that consideration, it probably doesn't need much at all to run 
RedBoot. If you are memory-constrained, you may want to look at various 
options to constrain the memory size and set those in the .ecm files. Also 
depending on the result you may need to increase the amount of reserved 
RAM for the ROM monitor in the MLT RAM startup files.

Note, before you get too excited about various things mentioning V850 ICE 
debug support, don't get too happy.... it required a Red Hat proprietary 
bit of software that was never (AFAIK) released. Sorry.

Jifl
-- 
eCosCentric    http://www.eCosCentric.com/    The eCos and RedBoot experts
--[ "You can complain because roses have thorns, or you ]--
--[  can rejoice because thorns have roses." -Lincoln   ]-- Opinions==mine


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[ECOS] Re: Porting RedBoot to NEC V850 platform

[Stephan Eisvogel]

Hi!

Thanks so much for all the input, I really appreciate it! Let me add
a few things:

Jonathan: I'll try gdb stub first and let you know if it works or if
problems did show up (I'm reading the list through the WWW archive on
http://sources.redhat.com/ml/ecos-discuss/ so I may be a bit slow to
respond, but that works very well for me).

Savin: Thanks for your hints! If you get back "home" _of course_ I
would like to look at your V850 RedBoot patches!

That said, I do know that V850 is not the latest and greatest of chips
compared to say the Intel Xscale or whatever, but our dept. is doing
mostly compact, fully-custom hardware solutions so I have no problem
with this, in fact having been an admin I'm used to running stuff for
200 people on a lowly P200. ;)

The kit I have here on my desk has 512K RAM and 512K flash plus some
more 128k of available internal flash, granted not really big. But if
RedBoot, eCos, GNU toolchain and most importantly the debugging works,
it will be no big deal to move the whole enchilada to much beefier
hardware for future projects.

Best Regards,
Stephan

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