Search notes:

/proc/sys/fs/binfmt_misc/

binfmt_misc stands for Miscellaneous Binary Format. It allows a user-mode application to register executable file formats that they can handle with the kernel.
The binfmt_misc functionality is used, for example, by

Files found under /proc/sys/fs/binfmt_misc

File's I've found under /proc/sys/fs/binfmt_misc include
register
status
WSLInterop Related to Windows Subsystem for Linux

Checking if binfmt_misc is enabled

$ cat /proc/sys/fs/binfmt_misc/status
enabled

Registering handlers

Handlers can be registered by writing into /proc/sys/fs/binfmt_misc/register.

See also

/proc/sys/fs/binfmt_misc/WSLInterop
The kernel source file fs/binfmt_misc.c

Links

Wikipedia: binfmt_misc
Kernel sourcet tree: Documentation/admin-guide/binfmt-msc.rst

Index