Wipy no float and math!

Questions and discussion about The WiPy 1.0 board and CC3200 boards.
Target audience: Users with a WiPy 1.0 or CC3200 board.
gpshead
Posts: 6
Joined: Tue Nov 03, 2015 5:12 am
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Re: Wipy no float and math!

Post by gpshead » Mon Jul 13, 2020 1:58 am

First, thanks for the pointers on what needs to be done to build with float support. That said, it isn't so simple. I understand why it was omitted.
sekil wrote:
Thu Mar 26, 2020 6:19 am
that is possible to make fw with working floating and math.. And no need reinvent crutches for floating values.. And no official info about how compile floating support on this board - only "due to ram limitation... bla bla" - but this working and with 45kb ram - and we need change cflags, ldflags and python configs..
It doesn't fit in the firmware image without disabling something else in turn in order to make room. When using the top of tree master branch I can create a build of v1.12-623-gf743bd3d2-dirty that has float support by adding the LIBM linking (as your application.mk suggests and other ports do), but in order for it to fit into an mcuimg.bin that is not rejected upon upload, I have to disable longint support (LONGINT_IMPL_NONE). (using the 2020-q2 gnu-arm-none-eabi compiler toolchain)

At this point, the legacy wipy has shipped, complete with the set of expectations it came with. Disabling a feature to make room for a new one in default shipped builds would break existing code. People who want something different can dive into building their own micropython. This isn't a modern microcontroller.

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$ make BTARGET=application BTYPE=release BOARD=WIPY
...
LINK build/WIPY/release/application.axf
   text	   data	    bss	    dec	    hex	filename
 196640	   1200	  64304	 262144	  40000	build/WIPY/release/application.axf
Create build/WIPY/release/application.bin
Create build/WIPY/release/mcuimg.bin
mcuimg.bin is 199272 bytes.

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>>> import machine
>>> machine.reset()
MicroPython v1.12-623-gf743bd3d2-dirty on 2020-07-12; WiPy with CC3200
Type "help()" for more information.
>>> import gc
>>> gc.mem_free()
39120
My diff used to build that is attached.

An unmodified build at that revision has an additional 13k of ram. floating point, after losing longint support, consumed 13k. Ouch. But not entirely surprising given the soft float implementation:

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>>> gc.mem_free()
52448
Attachments
micropython-v1.12-623-gf743bd3d2-wipy-float.diff.gz
diff to enable floating point in a wipy micropython build
(1.08 KiB) Downloaded 8 times

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