feat: publish FreeRTOS C FC06 card

scripts/check_abi.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env sh
+set -eu
+
+nm=$(printenv RISCV_NM || true)
+readelf=$(printenv RISCV_READELF || true)
+test -n "$nm" || nm=riscv64-unknown-elf-nm
+test -n "$readelf" || readelf=riscv64-unknown-elf-readelf
+elf=build/task01_software_timers/prog.elf
+
+if "$nm" --defined-only "$elf" | awk '{print $3}' | grep -Eq '^_Z|^__cxa_|^_Unwind_'; then
+  echo "unexpected C++ or unwind symbol in FC06" >&2
+  exit 1
+fi
+if "$readelf" -S "$elf" | grep -Eq '\.init_array|\.eh_frame|\.gcc_except_table'; then
+  echo "unexpected C++ initialization or unwind section in FC06" >&2
+  exit 1
+fi
+for symbol in fc06_timer_callback fc06_controller_entry fc06_verifier_entry \
+  fc06_checkpoint_committed xTimerCreateTimerTask xTimerGenericCommandFromTask \
+  xTimerGetTimerDaemonTaskHandle pvTimerGetTimerID; do
+  "$nm" --defined-only "$elf" | grep -Eq "[[:space:]]$symbol$" || {
+    echo "required symbol is missing: $symbol" >&2
+    exit 1
+  }
+done
+echo "PASS ABI: FC06 is freestanding C11 with software timer APIs"