Undefined reference to `_binary_src_certs_pem_start'

I want to use SSL, so I have put " certs.pem " in /src folder. In the main.c, I have put " extern const char cert_start[] asm("_binary_src_certs_pem_start"); ". and in platformio.ini, I have put " board_build.embed_txtfiles = src/certs.pem ". I have tried to build the code and clean before the build and the same error: …

Linking .pio/build/esp32dev/firmware.elf
/home/walidamriou/.platformio/packages/toolchain-xtensa32/bin/../lib/gcc/xtensa-esp32-elf/8.2.0/../../../../xtensa-esp32-elf/bin/ld: .pio/build/esp32dev/esp-idf/src/update.c.o:(.literal.update+0x4): undefined reference to `_binary_src_certs_pem_start'
collect2: error: ld returned 1 exit status
*** [.pio/build/esp32dev/firmware.elf] Error 1

…

I can fix the problem by using the certificate direct in the main.c but I want to use it as a file, this how I have used it in main.c:

const char* cert = \
"-----BEGIN CERTIFICATE-----\n" \
"MIIEkjCCA3qgAwIBAgIQCgFBQgAAAVOFc2oLheynCDANBgkqhkiG9w0BAQsFADA/\n" \
"MSQwIgYDVQQKExtEaWdpdGFsIFNpZ25hdHVyZSBUcnVzdCBDby4xFzAVBgNVBAMT\n" \
"DkRTVCBSb290IENBIFgzMB4XDTE2MDMxNzE2NDA0NloXDTIxMDMxNzE2NDA0Nlow\n" \
...
"wApIvJSwtmVi4MFU5aMqrSDE6ea73Mj2tcMyo5jMd6jmeWUHK8so/joWUoHOUgwu\n" \
"X4Po1QYz+3dszkDqMp4fklxBwXRsW10KXzPMTZ+sOPAveyxindmjkW8lGy+QsRlG\n" \
"PfZ+G6Z6h7mjem0Y+iWlkYcV4PIWL1iwBi8saCbGS5jN2p8M+X+Q7UNKEkROb3N6\n" \
"KOqkqm57TH2H3eDJAkSnh6/DNFu0Qg==\n" \
"-----END CERTIFICATE-----\n";

Any solutions or ideas to fix this problem?

[valeros]

Hi guys, sorry for the late reply. I pushed some changes together with updates for ESP-IDF v4.1 that could possibly fix this issue.

It would be great if you could retest your projects with the upstream version:

[env:upstream_develop]
platform = https://github.com/platformio/platform-espressif32.git
framework = esp-idf
board = ...

Symbol names should be without additional paths, e.g. _binary_coap_ca_pem_start for coap_ca.pem

[StavrosD]

https://github.com/platformio/platform-espressif32/issues/480#issuecomment-771187787