ESP32 Forum

I tried to put EXT_RAM_BSS_ATTR , example: EXT_RAM_BSS_ATTR cv::QRCodeDetector QRdetecter; but didnt't work , dram.bss still overload, i read there is also possible to place the BSS section of a component or a library to external RAM using linker fragment scheme extram_bss. But how? there is no further instruction.

There's an option for that somewhere in menuconfig. Note that you do need to annotate the bss variables you want in psram with a certain attribute; see the help for the menuconfig option.

ESP_Sprite wrote: ↑

Fri Mar 22, 2024 11:41 am

There's an option for that somewhere in menuconfig. Note that you do need to annotate the bss variables you want in psram with a certain attribute; see the help for the menuconfig option.

I know CONFIG_SPIRAM_ALLOW_BSS_SEG_EXTERNAL_MEMORY, Found in: Component config > ESP PSRAM > CONFIG_SPIRAM > SPI RAM config, I enable it before .I really don't konw how to ues extram_bss to make components .bss into PSRAM.bss

If you enable that, you can mark variables to live in PSRAM BSS rather than internal BSS. Example: would become
to allocate it in PSRAM.

ESP_Sprite wrote: ↑

Sat Mar 23, 2024 2:57 am

If you enable that, you can mark variables to live in PSRAM BSS rather than internal BSS. Example:

Code: Select all

char very_big_variable[1024*1024];

would become

Code: Select all

#include <esp_attr.h>
...
EXT_RAM_BSS_ATTR char very_big_variable[1024*1024];

to allocate it in PSRAM.

Thanks, i understand,it can't work on C++ CLASS.