MIPS32 port

[pito]

Probably in Q3 we will get a new PIC32MZ series - up to 2MB flash, 512kB ram, 200MHz clock, mips14k core, etc. Maybe an improvement over the old PIC32MX

[Dmytro]

No news for some time but it does not mean that the project is dead.
Since last time the port gained:
Chibios:
* HAL DMA driver(HAL interface, LLD template, unit tests)
* chprintf: support of autoinsertion of '\r'(compile-time switch)
* chprintf: chvprintf variant
MIPS port:
* execution of the constructors before the call to main()
PIC32 port:
* EXT LLD(used state change feature of the pin, EXTx interrupts are out of scope)
* DMA LLD
* DMA support in SPI driver
* misc fixes

What's next? I suppose I'll implement timers and RTC LLDs. Any feedback is very welcome!

[Dmytro]

Hi,
I did some benchmarks w/ release build of pic32mx demo. Clearly this thing beats ARM even the freq of pic32 is slightly higher in some cases. Even in comparison with STM32F407@168MHz it's clear that mips architecture is not that bad...

[Tectu]

Dear god... you're doing a very well job, respect!
May I drop a twitter line about your benchmarks?

Also, why is there an -O2 optimization flag for the PIC but not for the others?


~ Tectu

[Dmytro]

Hi Tectu, it's -O2 for the others too. I took the numbers from http://chibios.org/dokuwiki/doku.php?id=chibios:metrics#latest_test_reports.
Sure you can drop a tweet =)

[Dmytro]

Few updates in PIC32MX port:
Chibios:
* HAL RTC: extend API to support configuration settings
MIPS port:
* RTC LLD
* ADC LLD
* GFX LCD and touch panel integration(LLD headers submitted to GFX repo as well)
* minor non-critical fixes
* merge with mainline(mabl's repo)

[Dmytro]

Hi Giovanni,
I'm kindly raising the question about mip32 port inclusion into the mainline.
The port is almost complete. Missing LLDs I'm going to develop on demand(ethernet, PWM) but some of them I just can not test physically at this moment(like CAN).
IMHO pic32mx port enters maintenance phase.

What do you say?

[Giovanni]

Hi,

I am just doing bug fixing because I want to finalize a 2.6.0 release, it is way overdue, we may merge the code afterward.

BTW, if the CAN peripheral has a loopback mode you can test it just like I do for the STM32, see the demos.

Giovanni

[etmatrix]

Hi,
I did some benchmarks w/ release build of pic32mx demo. Clearly this thing beats ARM even the freq of pic32 is slightly higher in some cases. Even in comparison with STM32F407@168MHz it's clear that mips architecture is not that bad...

Hi Dmytro,
you got these benchmarks with this compiler http://developer.mips.com/tools/compile ... toolchain/. Is it correct?
I tried with XC32 PRO and CodeSourcery and I got no good results. They was worst, with big distance. I don't remember exactly all differences, but were not good.
I will try to recompile the toolchain for my linux box X86 and I will try again the benchmarks.

[Dmytro]

Hi etmatrix,
I'm using prebuilt toolchain from mips.com(mips-sde-elf-gcc (GCC) 4.4.6) but there should not be any difference between native build of the toolchain and binary delivery.
I noticed some performance regression with gcc 4.6(or 4.7 don't remember exactly) so pay attention there.
Be careful when benchmarking the demo in mips port as it has all debug/development stuff enabled. Check for CH_DBG_* in chconf.h. Other demos do not include these checks.
Also take into account that the demo is quite big and full of timers, events, threads that may impact the benchmark numbers.

thanks,
~ dmytro