* [utest/mm] add testcase for create/init
format codes of create/init in components/mm
* [libcpu/aarch64] fix user stack check routine
* [kservice] export API for utest
* [utest/mm] testcase for aspace_map
format & modify the files under components/mm related with aspace_map
* [lwp/user_mm] add user_map_varea for mmap feature
* [mm] rename rt_mm_fault_try_fix to rt_aspace_fault_try_fix
* [utest/mm] testcase for synchronization
* [mm] modify unmap api to improve throughput
* [utest/mm] testcases for cache and varea map
* [format] remove extra space
* [utest/mm] fix testcase problem in header
* [lwp] extend map_user_varea with a flag
* [utest/mm] testcase for lwp_map_user_varea
* [libcpu/arm/cortex-a] fix kernel space layout
* [utest/mm] adjust for armv7 arch
* [mm] mmu operations should be wrapped by _aspace_bst_insert & _aspace_bst_remove to avoid competition on page table
* [lwp] may not return null on failed
* [libcpu/risc-v] support noncached normal memory
* [mm] check before dereference in _fetch_page
* [mm] add comments on ioremap
* [ioremap] report more info on failed
* [rt-smart/mem] remove pv_offset
* [rt-smart] list kernel space command
* [rt-smart] restore ioremap region
* [revert] restore kernel space isolation
* [rt-smart/pv_off] code format
* [rt-smart] add get_pvoff()
* [pvoffset] pvoff as constant for C codes
* [pvoff] pvoff as interfaces
* [rv64/bsp] porting to mm
* [mm] report more info for debugging
* [fix] code format
* [libcpu/c906] porting to RTOS
* [fix] using rtdbg api
* [fix] add return
* [fix] report more information for debugging
* [fix] use assert 0 for unrecoverable error