linux/scripts/mksysmap

#!/bin/sh -x
# Based on the vmlinux file create the System.map file
# System.map is used by module-init tools and some debugging
# tools to retrieve the actual addresses of symbols in the kernel.
#
# Usage
# mksysmap vmlinux System.map


#####
# Generate System.map (actual filename passed as second argument)

# $NM produces the following output:
# f0081e80 T alloc_vfsmnt

#   The second row specify the type of the symbol:
#   A = Absolute
#   B = Uninitialised data (.bss)
#   C = Common symbol
#   D = Initialised data
#   G = Initialised data for small objects
#   I = Indirect reference to another symbol
#   N = Debugging symbol
#   R = Read only
#   S = Uninitialised data for small objects
#   T = Text code symbol
#   U = Undefined symbol
#   V = Weak symbol
#   W = Weak symbol
#   Corresponding small letters are local symbols

# For System.map filter away:
#   a - local absolute symbols
#   U - undefined global symbols
#   N - debugging symbols
#   w - local weak symbols

# readprofile starts reading symbols when _stext is found, and
# continue until it finds a symbol which is not either of 'T', 't',
# 'W' or 'w'.
#
# Ignored prefixes:
#  $                    - local symbols for ARM, MIPS, etc.
#  .L                   - local labels, .LBB,.Ltmpxxx,.L__unnamed_xx,.LASANPC, etc.
#  __crc_               - modversions
#  __kstrtab_           - EXPORT_SYMBOL (symbol name)
#  __kstrtabns_         - EXPORT_SYMBOL (namespace)
#
# Ignored symbols:
#  L0                   - for LoongArch?

$NM -n $1 | grep -v		\
	-e ' [aNUw] '		\
	-e ' \$'		\
	-e ' \.L'		\
	-e ' __crc_'		\
	-e ' __kstrtab_'	\
	-e ' __kstrtabns_'	\
	-e ' L0$'		\
> $2