export CTR_SDK_ROOT=/opt/ctr-sdk-4-2-8 export PATH=$CTR_SDK_ROOT/tools/bin:$PATH export CTR_TARGET=cortex-m4 ctr-cli --version Expected output:
__attribute__((aligned(4))) const uint8_t device_desc[] = ... ; Symptom : Log shows MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE . Cause : Patch 8 enforces TLS 1.2 minimum; older servers using TLS 1.0 fail. Fix : In mqtt_config.h , set: ctr-sdk-4-2-8
cd /path/to/old/project $CTR_SDK_ROOT/tools/migrate_to_4_2_8.py --src . --dst ./migrated Review the generated migration_report.txt for manual fix suggestions. We ran benchmarks on a STM32F407 (Cortex-M4, 168 MHz) comparing ctr-sdk-4-2-8 against v4.0.5 and v3.6.2. ctr-sdk-4-2-8