GCC: (Buildroot 2012.02) 4.5.3 
.symtab .strtab .shstrtab .rel.text .data .bss .comment .note.GNU-stack .ARM.attributes 
hmac_sha256.c $a hmac_sha256 memset memcpy SHA256_Init SHA256_Update SHA256_Final hmac_sha256_n sha256 KDF