mbedtls and littlefs on a STM32L4

[jhfigueiredo]

Discussed in #37329

^{Originally posted by jhfigueiredo July 30, 2021}
I'm quite new to Zephyr so this might just be some missing configuration or lack of knowledge.
The objective is to load a x509 certificate from the filesystem (littlefs) using the mbedtls mbedtls_x509_crt_parse_file function. For that I need to include MBEDTLS_FS_IO. But when I do include this configuration it includes <dirent.h> which then returns the following error:

In file included from /home/jhf/zephyr-sdk-0.12.4/arm-zephyr-eabi/arm-zephyr-eabi/sys-include/dirent.h:39,
from /home/jhf/zephyrproject/modules/crypto/mbedtls/mbedtls/library/x509_crt.c:78:
/home/jhf/zephyr-sdk-0.12.4/arm-zephyr-eabi/arm-zephyr-eabi/sys-include/sys/dirent.h:10:2: error: #error "<dirent.h> not supported"
10 | #error "<dirent.h> not supported"
| ^~~~~

I have a work around but would imply changes to the mbedtls original code, which I really would try to avoid.
Any help would be appreciated.

[cfriedt]

@jhfigueiredo - please continue in the original discussion.