Cannot access External Flash memory when External SPI Ram enabled

[nimeshk]

Code: Untitled.txt Select all

Hello,
My project has a requirement for external flash memory to store some data as well as the internal ram is not sufficient so I have to enable external SPI ram under menuconfig to store .bss data. I referred to the example code https://github.com/espressif/esp-idf/tr ... lash_fatfs. So when I make changes to example code as per my requirement I get this "ESP_ERR_INVALID_ARG" error from this function "spi_bus_add_flash_device". I am attaching the sdkconfig files with the changes that I have made please use those in the code that you build.

ext_flash.png (189.44 KiB) Viewed 8538 times

[devanl]

Hi,

It sounds like you've run into an issue that I reported a while back:
https://github.com/espressif/esp-idf/issues/4379

As a work-around until Espressif makes a fix, you can patch spi_bus_add_flash_device() to always use MALLOC_CAP_INTERNAL when allocating memory for the SPI bus driver struct.

[nimeshk]

Thanks, it worked.

[nimeshk]

@devanl will this workaround cause any issues in the heap allocation?

[devanl]

@devanl will this workaround cause any issues in the heap allocation?

Not that I'm aware of - the structs being allocated in spi_bus_add_flash_device() look pretty small to me - just function pointers and other assorted fields, no giant buffers or anything.

[nimeshk]

@devanl will this workaround cause any issues in the heap allocation?

Not that I'm aware of - the structs being allocated in spi_bus_add_flash_device() look pretty small to me - just function pointers and other assorted fields, no giant buffers or anything.

Thanks

[Hydneman]

Hi, we have just found that when using SPIRAM_USE_MALLOC, it may call a wrong logic. Your issue is very similar to this. Please take a look on https://github.com/espressif/esp-idf/issues/4379. I hope the comment following will help you.