Search notes:

/boot/System.map

Although located in the /boot directory, it is not needed to boot Linux.
System.map is a symbol file for the kernel. It lists function entry points and addresses of kernel data structures of a particular build of a kernel.
It is used by klogd, ksymoops, OOPS etc. and might generally be useful to investigate kernel problems.

See also

System.map
The Debian/APT package linux-image-$(uname -r) contains files such as /boot/System.map-$(uname -r) etc.
/proc/kallsyms

Index

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