newlib/thread_safety/prj_userspace.conf

CONFIG_ZTEST=y
CONFIG_NEWLIB_LIBC=y
CONFIG_NEWLIB_LIBC_MIN_REQUIRED_HEAP_SIZE=0
CONFIG_TIMESLICE_SIZE=1

CONFIG_TEST_USERSPACE=y
CONFIG_MAX_THREAD_BYTES=10
CONFIG_HEAP_MEM_POOL_SIZE=2048