interpreters/python: Optmize Python for size

[tmedicci]

Summary

Reduce general firmware size by optimizing Python-related sources.

Impact

Impact on user: Yes. Enable reducing firmware size when CONFIG_INTERPRETERS_CPYTHON is enabled.

Impact on build: Yes. Reduce firmware size by ~6% (tested on ESP32-P4)

Impact on hardware: No.

Impact on documentation: No.

Impact on security: No.

Impact on compatibility: No.

Testing

Build esp32p4-function-ev-board:python defconfig before and after applying this patch.

Building

make -j distclean && ./tools/configure.sh -S esp32p4-function-ev-board:python && make -s -j$(nproc)

Running

After flashing the device, just run python on NSH to ensure that it's being properly initialized.

Results

Comparison between the firmwares built before and after applying this patch:

Before

Memory region         Used Size  Region Size  %age Used
   tcm_idram_seg:         136 B         8 KB      1.66%
        irom_seg:     3159284 B        64 MB      4.71%
        sram_seg:      374776 B     978880 B     38.29%
        drom_seg:    16062776 B        64 MB     23.94%
rev3_mspi_workaround_seg:           0 B          0 B
      lp_ram_seg:         104 B      32744 B      0.32%
 lp_reserved_seg:          24 B         24 B    100.00%
  extern_ram_seg:          2 MB        64 MB      3.12%
CP: nuttx.hex

And the final firmware size:

-rw-r--r-- 1 tiago tiago 16454900 jun 15 11:32 nuttx.bin

After

Memory region         Used Size  Region Size  %age Used
   tcm_idram_seg:         136 B         8 KB      1.66%
        irom_seg:     2192720 B        64 MB      3.27%
        sram_seg:      374776 B     978880 B     38.29%
        drom_seg:    15034520 B        64 MB     22.40%
rev3_mspi_workaround_seg:           0 B          0 B
      lp_ram_seg:         104 B      32744 B      0.32%
 lp_reserved_seg:          24 B         24 B    100.00%
  extern_ram_seg:          2 MB        64 MB      3.12%
CP: nuttx.hex

And the final firmware size:

-rw-r--r-- 1 tiago tiago 15422800 jun 15 11:41 nuttx.bin

[cederom]

+1 from me, out of lab ;-)

…

-- CeDeROM, SQ7MHZ, http://www.tomek.cedro.info

[tmedicci]

Anything else? Can it be merged?

[acassis]

Anything else? Can it be merged?

Please change later the OPT to use the defined optimization from NuttX config or open an issue to track it if you cannot work on it for now