ICACHE_FLASH_ATTR

[benoitLecuppe]

Bonjour,

I'm working on esppwm.c. Most functions have the attribute ICACHE_FLASH_ATTR .
This attribute indicates to the linker to put the code in .irom0.text section.
if I undefine ICACHE_FLASH_ATTR, I have an error "build-GENERIC/firmware.elf section .text' will not fit in region iram1_0_seg'".
My question is : how the other modules, like hspi.c for exemple , are putting the code in .irom.text section without using ICACHE_FLASH_ATTR ?

Merci :-)
Benoit

[jimmo]

@benoitLecuppe

This is a bit subtle... esp8266_common.ld will place anything by default into iram1_0_seg. However there are a list of specific object files above that are explicitly placed in irom0_0_seg. (This includes hspi.o but does not include esppwm.o).

So ICACHE_FLASH_ATTR is used explicitly in esppwm.c to place certain functions into .irom0.text (i.e. irom0_0_seg) because by default everything in that file is going into iram1_0_seg. When you undefine that macro, everything in that file now goes to iram1_0_seg, overflowing it.

[benoitLecuppe]

Merci,

I understand. I put esppwm.o in esp8266_common.ld and It's work.
Have you an idea of the reason why esppwm.o is not in esp8266_common.ld ?

[jimmo]

Have you an idea of the reason why esppwm.o is not in esp8266_common.ld ?

@benoitLecuppe Not sure, sorry. I think it would probably be clearer if it was and then explicitly marked the functions that should be in iram.