How to implement these functions at the bottom of file IO using littlefs

[shadowYYMM]

I use RT-THREAD nano version system, after porting littlefs to nor flash, I can not realize the open, close, read, write functions in file IO

How to implement these functions at the bottom of file IO using littlefs：
int _open_r(struct _reent *ptr, const char *file, int flags, int mode)；
int _close_r(struct _reent *ptr, int fd)；
_ssize_t _read_r(struct _reent *ptr, int fd, void *buf, size_t nbytes)；
_ssize_t _write_r(struct _reent *ptr, int fd, const void *buf, size_t nbytes)；

[wdfk-prog]

I use RT-THREAD nano version system, after porting littlefs to nor flash, I can not realize the open, close, read, write functions in file IO我用的是RT-THREAD nano版本的系统，把littlefs移植到nor flash后，无法实现文件IO的开、关、读、写功能

How to implement these functions at the bottom of file IO using littlefs：如何使用 littlefs 在文件 IO 的底部实现这些函数： int _open_r(struct _reent *ptr, const char *file, int flags, int mode)； int _close_r(struct _reent *ptr, int fd)； _ssize_t _read_r(struct _reent *ptr, int fd, void *buf, size_t nbytes)； _ssize_t _write_r(struct _reent *ptr, int fd, const void *buf, size_t nbytes)；

• Reference package Implementation,

https://github.com/RT-Thread-packages/littlefs/blob/master/dfs_lfs.c

[shadowYYMM]

我用的是RT-THREAD nano版本的系统，把littlefs移植到nor flash后，我无法实现IO文件中的打开、关闭、读、写功能我用的是RT-THREAD nano版本的系统，把littlefs移植到nor flash后，无法实现文件IO的开、关、读、写功能
如何使用 littlefs 在文件 IO 的底部实现这些函数：如何使用 littlefs 在文件 IO 的底部实现这些函数：int _open_r(struct _reent *ptr, const char *file, int flags, int mode)； int _close_r(struct _reent *ptr, int fd)； _ssize_t _read_r(struct _reent *ptr, int fd, void *buf, size_t nbytes)； _ssize_t _write_r(struct _reent *ptr, int fd, const void *buf, size_t nbytes)；

• 参考包实现，

https://github.com/RT-Thread-packages/littlefs/blob/master/dfs_lfs.c

The nano version does not have a dfs component

/usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-closer.o): in function _close_r':
/build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/closer.c:47:(.text._close_r+0xc): undefined reference to _close' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-lseekr.o): in function _lseek_r':
/build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/lseekr.c:49:(.text._lseek_r+0x14): undefined reference to _lseek' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-readr.o): in function _read_r':
/build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/readr.c:49:(.text._read_r+0x14): undefined reference to _read' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-writer.o): in function _write_r':
/build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/writer.c:49:(.text._write_r+0x14): undefined reference to _write' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-fstatr.o): in function _fstat_r':
/build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/fstatr.c:55:(.text._fstat_r+0x12): undefined reference to _fstat' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-isattyr.o): in function _isatty_r':
/build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/isattyr.c:52:(.text._isatty_r+0xc): undefined reference to _isatty' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-signalr.o): in function _kill_r':
/build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/signalr.c:53:(.text._kill_r+0x12): undefined reference to _kill' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-signalr.o): in function _getpid_r':
/build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/signalr.c:83:(.text._getpid_r+0x0): undefined reference to _getpid'

[wdfk-prog]

我用的是RT-THREAD nano版本的系统，把littlefs移植到nor flash后，我无法实现IO文件中的打开、关闭、读、写功能我用的是RT-THREAD nano版本的系统，把littlefs移植到nor flash后，无法实现文件IO的开、关、读、写功能
如何使用 littlefs 在文件 IO 的底部实现这些函数：如何使用 littlefs 在文件 IO 的底部实现这些函数：int _open_r(struct _reent *ptr, const char *file, int flags, int mode)； int _close_r(struct _reent *ptr, int fd)； _ssize_t _read_r(struct _reent *ptr, int fd, void *buf, size_t nbytes)； _ssize_t _write_r(struct _reent *ptr, int fd, const void *buf, size_t nbytes)；

• 参考包实现，

https://github.com/RT-Thread-packages/littlefs/blob/master/dfs_lfs.c

The nano version does not have a dfs component

/usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-closer.o): in function _close_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/closer.c:47:(.text._close_r+0xc): undefined reference to _close' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-lseekr.o): in function _lseek_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/lseekr.c:49:(.text._lseek_r+0x14): undefined reference to _lseek' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-readr.o): in function _read_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/readr.c:49:(.text._read_r+0x14): undefined reference to _read' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-writer.o): in function _write_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/writer.c:49:(.text._write_r+0x14): undefined reference to _write' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-fstatr.o): in function _fstat_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/fstatr.c:55:(.text._fstat_r+0x12): undefined reference to _fstat' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-isattyr.o): in function _isatty_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/isattyr.c:52:(.text._isatty_r+0xc): undefined reference to _isatty' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-signalr.o): in function _kill_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/signalr.c:53:(.text._kill_r+0x12): undefined reference to _kill' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-signalr.o): in function _getpid_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/signalr.c:83:(.text._getpid_r+0x0): undefined reference to _getpid'

Reference only,nano can only write its own;

[shadowYYMM]

我用的是RT-THREAD nano版本的系统，把littlefs移植到nor flash后，我无法实现IO文件中的打开、关闭、读、写功能我用的是RT-THREAD nano版本的系统，把littlefs移植到nor flash后，无法实现文件IO的开、关、读、写功能
如何使用 littlefs 在文件 IO 的底部实现这些函数：如何使用 littlefs 在文件 IO 的底部实现这些函数：int _open_r(struct _reent *ptr, const char *file, int flags, int mode)； int _close_r(struct _reent *ptr, int fd)； _ssize_t _read_r(struct _reent *ptr, int fd, void *buf, size_t nbytes)； _ssize_t _write_r(struct _reent *ptr, int fd, const void *buf, size_t nbytes)；

• 参考包实现，

https://github.com/RT-Thread-packages/littlefs/blob/master/dfs_lfs.c

The nano version does not have a dfs component
/usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-closer.o): in function _close_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/closer.c:47:(.text._close_r+0xc): undefined reference to _close' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-lseekr.o): in function _lseek_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/lseekr.c:49:(.text._lseek_r+0x14): undefined reference to _lseek' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-readr.o): in function _read_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/readr.c:49:(.text._read_r+0x14): undefined reference to _read' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-writer.o): in function _write_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/writer.c:49:(.text._write_r+0x14): undefined reference to _write' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-fstatr.o): in function _fstat_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/fstatr.c:55:(.text._fstat_r+0x12): undefined reference to _fstat' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-isattyr.o): in function _isatty_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/isattyr.c:52:(.text._isatty_r+0xc): undefined reference to _isatty' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-signalr.o): in function _kill_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/signalr.c:53:(.text._kill_r+0x12): undefined reference to _kill' /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/bin/ld: /usr/lib/gcc/arm-none-eabi/13.2.0/../../../../arm-none-eabi/lib/thumb/v7e-m+fp/hard/libg.a(libc_a-signalr.o): in function _getpid_r': /build/arm-none-eabi-newlib/src/build-newlib/arm-none-eabi/thumb/v7e-m+fp/hard/newlib/../../../../../../newlib-4.3.0.20230120/newlib/libc/reent/signalr.c:83:(.text._getpid_r+0x0): undefined reference to _getpid'

Reference only,nano can only write its own;

Thanks for your answer.I'm trying to write it