* Synchronize the code of the rt mart branch to the master branch.
* TTY device
* Add lwP code from rt-smart
* Add vnode in DFS, but DFS will be re-write for rt-smart
* There are three libcpu for rt-smart:
* arm/cortex-a, arm/aarch64
* riscv64
Co-authored-by: Rbb666 <zhangbingru@rt-thread.com>
Co-authored-by: zhkag <zhkag@foxmail.com>
* [posix] POSIX standard implementation for PSE51
- add some posix's interfaces that we haven't before.
- these PR have passed the interface definition test across gcc platfrom;
- have tested base on qemu-a9 and stm32h750-art-pi.
* [newlib] only enable POSIX.1-1990
* update projects
* [kernel][mem] Multiple instances of small memory allocation algorithm
* [kernel][mem] Change small memory management algorithm memory header flag
* [kernel][mem] Fix assertion problem
* [kernel][slab] Multiple instances of slab memory management algorithm
* [kernel][memheap] Remove rt_malloc/rt_free/rt_realloc and other related memory interfaces
* [kernel][mem] Clean up memory space of small memory management objects
* [kernel][kservice] Add memory application interface and thread protection interface
* [kernel][kservice] Fix function return value problem
* [kernel][memheap] Optimize memheaptrace print
* [kernel][memheap] Support best mode
* [kernel][memory] Remove semaphore lock
* [kernel][memheap] Add locked flag
* [kernel][memory] Support malloc memory in interrupt
* [kernel][memheap] Add 'memheapcheck' cmd
* [kernel][mem] Fix failure to request full memory
* [kernel][memheap] Fix compilation warning
* [kernel][mem] Fix mem realloc ASSERT
* [examples][testcases] Add small mem testcase
* [examples][mem_tc] Modify test memory size
* [examples][testcases] Add slab memory management algorithm test case
* [examples][testcases] fix small memory management algorithm test case
* [kernel][memory] Adjusting memory allocation algorithm object definition and interface
* [kernel][memory] Fix compilation warning
* [examples][utest] Fix mem test case
* [examples][utest] fix slab test case
* [utest][testcases] Shorten test time
* [kernel][memory] Formatting code
* [examples][utest] Adjust test run time
* [examples][utest] Formatting code
* [bsp] update all rtconfig.h
2. Modify the return code to -1 when failed
3. Change the mounting filesystem from ramfs to sdcard
4. Replace RT_USING_RTGUI with PKG_USING_GUIENGINE and remove RT_USING_FTK