carlk3/no-OS-FatFS-SD-SDIO-SPI-RPi-Pico

Reduce build size

Closed this issue · 3 comments

hellcats88 commented

Hi,

I'm compiling for RP2040 pi pico board and my sketch with GxEPD2 and LVGL libraries has a size of 165KB.
When I add your library and only the code

FATFS fs;
    FRESULT fr = f_mount(&fs, "", 1);
    if (FR_OK != fr) {
        panic("f_mount error: %s (%d)\n", FRESULT_str(fr), fr);

the build generates an uf2 file with 249KB.
Why this huge size? I already have used flasg like

add_compile_options(-ffunction-sections -fdata-sections)
target_link_options(candle PUBLIC "-Wl,--gc-sections")

Can you help me to reduce the size? Is there any trick I have not applied?

carlk3 commented

I don't know that the uf2 file size is a good indication. Something like -Wl,--print-memory-usage would probably be better.

You might try the -Os GCC command option.

carlk3 commented

To minimize the size of this library, set these C preprocessor macros to 0:

  • USE_PRINTF
  • USE_DBG_PRINTF
  • SD_CRC_ENABLED

and set this to 1:

  • NDEBUG
hellcats88 commented

These are the results of the new compilation, for me now is better and I thinks that will be sufficient.

WITHOUT f_mount invocation:

add_compile_options(-ffunction-sections -fdata-sections)
target_link_options(candle PUBLIC "-Wl,--gc-sections")
add_compile_options(-Os)

Memory region         Used Size  Region Size  %age Used
           FLASH:       69096 B         2 MB      3.29%
             RAM:        256 KB       256 KB    100.00%
       SCRATCH_X:          0 GB         4 KB      0.00%
       SCRATCH_Y:          0 GB         4 KB      0.00%

WITH f_mount invocation:

add_compile_options(-ffunction-sections -fdata-sections)
target_link_options(candle PUBLIC "-Wl,--gc-sections")

Memory region         Used Size  Region Size  %age Used
           FLASH:      127156 B         2 MB      6.06%
             RAM:        256 KB       256 KB    100.00%
       SCRATCH_X:          0 GB         4 KB      0.00%
       SCRATCH_Y:          0 GB         4 KB      0.00%

add_compile_options(-ffunction-sections -fdata-sections)
target_link_options(candle PUBLIC "-Wl,--gc-sections")
add_compile_options(-Os)

Memory region         Used Size  Region Size  %age Used
           FLASH:      111696 B         2 MB      5.33%
             RAM:        256 KB       256 KB    100.00%
       SCRATCH_X:          0 GB         4 KB      0.00%
       SCRATCH_Y:          0 GB         4 KB      0.00%

add_compile_options(-ffunction-sections -fdata-sections)
target_link_options(candle PUBLIC "-Wl,--gc-sections")
add_compile_options(-Os)
add_compile_definitions(USE_PRINTF=0)
add_compile_definitions(USE_DBG_PRINTF=0)
add_compile_definitions(SD_CRC_ENABLED=0)
add_compile_definitions(NDEBUG=1)

Memory region         Used Size  Region Size  %age Used
           FLASH:      106376 B         2 MB      5.07%
             RAM:        256 KB       256 KB    100.00%
       SCRATCH_X:          0 GB         4 KB      0.00%
       SCRATCH_Y:          0 GB         4 KB      0.00%