feat: add lab-rv32i-freertos-mutex card

scripts/check_abi.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env sh
+set -eu
+nm=${RISCV_NM:-riscv64-unknown-elf-nm}
+readelf=${RISCV_READELF:-riscv64-unknown-elf-readelf}
+elf=build/task01_mutex/prog.elf
+if "$nm" -C -u "$elf" | grep -Eq '__cxa_|_Unwind_|std::|libstdc\+\+'; then echo "hosted C++ runtime dependency" >&2; exit 1; fi
+if "$nm" -C --defined-only "$elf" | grep -Eq 'vtable for|typeinfo for|typeinfo name for'; then echo "virtual/RTTI metadata" >&2; exit 1; fi
+if "$readelf" -S "$elf" | grep -Eq '\.init_array|\.eh_frame|\.gcc_except_table'; then echo "initializer/exception/unwind section" >&2; exit 1; fi
+for symbol in mutex_debug_checkpoint g_low_inherited_priority g_owner_low g_mutex_pass; do
+  if ! "$nm" --defined-only "$elf" | grep -Fq "$symbol"; then echo "missing evidence: $symbol" >&2; exit 1; fi
+done
+if ! "$nm" -C --defined-only "$elf" | grep -E '[[:space:]][bB][[:space:]].*g_mutex_storage' >/dev/null; then
+  echo "static mutex storage is not in .bss" >&2; exit 1
+fi
+echo "PASS ABI: static mutex storage in .bss; no vtable/runtime/init array"