Re: system.map

Lionel Bouton
2002-01-02T21:26:04Z

Sebastian Roth wrote:

>>Hi all
>>
>
> hello,
>
>
>>Why sometimes I don't need to copy the system.map to
>>/boot when I update the kernel
>>and the system also can boot?
>>
>
>>Is it correct?
>>
>
> yes, this is correct. I think this System.map contains only some useful
> information about modules for the kernel.

> [...]

"man klogd", "man ksymoops".

Short:
System.map is an ordered (by address) list of (kernel address, ?type?,
and syscall name).
Module syscalls are dynamic by nature so there's a kernel interface for
exporting symbols to user utilities needing their addresses (see
/proc/ksyms).

You don't need System.map to boot. But user space apps like ps (can show
the current syscall used by a process), klogd (for clean GPF reports),
ksymoops (mainly as a cross-check with vmlinux symbols) use it and
search it in numerous places : with or without `-uname -r` appended (at
least in / /boot /usr/src/linux).

LB.