dm: crash for DM_FLAG_PRE_RELOC

[Heinrich Schuchardt]

Hello Simon,

I try to boot pine64-lts_defconfig + CONFIG_RSA=y.

SPL loads BL31. BL31 starts U-Boot. But before any output appears SPL is
restarted. So some crash must occur.

If I remove the flag DM_FLAG_PRE_RELOC in
drivers/crypto/rsa_mod_exp/mod_exp_sw.c, booting works fine.

Assigning the driver to UCLASS_NOP does not resolve the problem. So it
seems not to be a problem with the u-class.

Enlarging CONFIG_SPL_SYS_MALLOC_F_LEN and CONFIG_SYS_MALLOC_F_LEN does
not resolve the problem.

As the failure occurs very early no console is available for debug
output. Defining LOG_DEBUG at the top of drivers/core/list.c provides no
output.

Do you have an idea how to identify the root cause of the problem?

@Ruchika
Why is this driver loaded before relocation? I cannot find any usage of
function rsa_verify_key() before relocation.

Best regards

Heinrich