ChibiOS OpenOCD support

[mabl]

Without GC:

Code: Select all

-> % grep ch_debug build/ch.map
                0x0000000020000800                ch_debug
ch_debug                                          build/obj/chregistry.o

With GC:

Code: Select all

-> % grep ch_debug build/ch.map
 .data.ch_debug
ch_debug                                          build/obj/chregistry.o

Isn't it possible to change the linker files?

[Giovanni]

That would be the easy way to do that, I begin to doubt it is possible by using clean C without use an explicit pointer in some RAM structure.

Giovanni

[Giovanni]

I found a way to refer it without wasting 4 bytes (a lame trick).

It should be OK now, note that the ch_debug structure changed slightly.

Giovanni

[mabl]

Hi Giovanni, won't those 4 bytes be wasted by the function call? Or is the GCC to supid to optimize it all away?

[Tectu]

I tried it out and everything worked out of the box!
Thank you very much for your work, mabl. This will be really useful!

It would be nice if the USE_LINK_GC stuff would be fixed soon


~ Tectu

[Giovanni]

Hi Giovanni, won't those 4 bytes be wasted by the function call? Or is the GCC to supid to optimize it all away?

It is a macro not a function and it stores the pointer in a thread structure, the pointer points to "main" so the structure is really referred. The p_name field of the main thread points to ch_debug.

Giovanni

[mabl]

Hi Giovanni,

i've included the changes. Cool trick with "main" But now you cannot just check if a device runs chibios by reading out the Flash and doing a search for CHRT.

EDIT:
Have you thought about backporting the changes to the Stable Branch? There should not be much impact, right?

[Giovanni]

You can search for "main", zero followed by the size and the various other fields of the structure that are quite recognizable.

The backport can be done, I have to verify if there are other dependencies.

Giovanni

[Tectu]

I could try it out. I cloned the latest ChibiOS master from github and also the latest OpenOCD master from mabl.
Now it works with USE_LINKER_GC on

nice work!


~ Tectu

[mabl]

Giovanni,

the oocd RTOS detection routine depends on detecting symbols unique to the operating system. Currently I only use "rlist" for detection. Are there other symbols I can assume to be always there and not change their name in the future? Like chSysInit and _idle_thread?