From 27e0d4b0510700108341c50661f78a10969648df Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Mon, 7 Aug 2017 16:01:12 -0700 Subject: [PATCH] MIPS: generic: Allow filtering enabled boards by requirements Up until now when configuring a generic kernel all board config fragments have been merged by default unless boards are explicitly selected by the user specifying BOARDS=. In many cases this is sub-optimal, since some boards don't make sense to include in some kernels. For example the MIPS SEAD-3 development board has only ever been used with 32 bit CPUs, so including support for the SEAD-3 in a 64 bit kernel is wasteful. This patch introduces support for specifying requirements in board config fragments, using comments formatted like so: # require CONFIG_BLA=y For example the SEAD-3 board could specify that it should only be merged for 32 bit kernels using a requirement line like the following: # require CONFIG_32BIT=y A new generic-board-config.sh script is introduced to handle selecting the board config fragments to merge & calling merge_config.sh to merge them. In order to allow requirements to check Kconfig symbols that are implicitly selected, rather than explicitly specified by generic_defconfig or one of the ISA config fragments, an intermediate .config file is saved & used as a reference when checking requirements. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16943/ Signed-off-by: Ralf Baechle --- MAINTAINERS | 1 + arch/mips/Makefile | 10 ++- arch/mips/tools/generic-board-config.sh | 90 +++++++++++++++++++++++++ 3 files changed, 99 insertions(+), 2 deletions(-) create mode 100755 arch/mips/tools/generic-board-config.sh diff --git a/MAINTAINERS b/MAINTAINERS index 31d4274efb06..b526acd23ae1 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8792,6 +8792,7 @@ M: Paul Burton L: linux-mips@linux-mips.org S: Supported F: arch/mips/generic/ +F: arch/mips/tools/generic-board-config.sh MIPS/LOONGSON1 ARCHITECTURE M: Keguang Zhang diff --git a/arch/mips/Makefile b/arch/mips/Makefile index 38360f776b6f..0e0aa64a9c88 100644 --- a/arch/mips/Makefile +++ b/arch/mips/Makefile @@ -500,8 +500,14 @@ $(eval $(call gen_generic_defconfigs,micro32,r2,eb el)) .PHONY: $(generic_defconfigs) $(generic_defconfigs): $(Q)$(CONFIG_SHELL) $(srctree)/scripts/kconfig/merge_config.sh \ - -m -O $(objtree) $(srctree)/arch/$(ARCH)/configs/generic_defconfig $^ \ - $(foreach board,$(BOARDS),$(generic_config_dir)/board-$(board).config) + -m -O $(objtree) $(srctree)/arch/$(ARCH)/configs/generic_defconfig $^ | \ + grep -Ev '^#' + $(Q)cp $(KCONFIG_CONFIG) $(objtree)/.config.$@ + $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig \ + KCONFIG_CONFIG=$(objtree)/.config.$@ >/dev/null + $(Q)$(CONFIG_SHELL) $(srctree)/arch/$(ARCH)/tools/generic-board-config.sh \ + $(srctree) $(objtree) $(objtree)/.config.$@ $(KCONFIG_CONFIG) \ + "$(origin BOARDS)" $(BOARDS) $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig # diff --git a/arch/mips/tools/generic-board-config.sh b/arch/mips/tools/generic-board-config.sh new file mode 100755 index 000000000000..5c4f93687039 --- /dev/null +++ b/arch/mips/tools/generic-board-config.sh @@ -0,0 +1,90 @@ +#!/bin/sh +# +# Copyright (C) 2017 Imagination Technologies +# Author: Paul Burton +# +# This program is free software; you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by the +# Free Software Foundation; either version 2 of the License, or (at your +# option) any later version. +# +# This script merges configuration fragments for boards supported by the +# generic MIPS kernel. It checks each for requirements specified using +# formatted comments, and then calls merge_config.sh to merge those +# fragments which have no unmet requirements. +# +# An example of requirements in your board config fragment might be: +# +# # require CONFIG_CPU_MIPS32_R2=y +# # require CONFIG_CPU_LITTLE_ENDIAN=y +# +# This would mean that your board is only included in kernels which are +# configured for little endian MIPS32r2 CPUs, and not for example in kernels +# configured for 64 bit or big endian systems. +# + +srctree="$1" +objtree="$2" +ref_cfg="$3" +cfg="$4" +boards_origin="$5" +shift 5 + +cd "${srctree}" + +# Only print Skipping... lines if the user explicitly specified BOARDS=. In the +# general case it only serves to obscure the useful output about what actually +# was included. +case ${boards_origin} in +"command line") + print_skipped=1 + ;; +environment*) + print_skipped=1 + ;; +*) + print_skipped=0 + ;; +esac + +for board in $@; do + board_cfg="arch/mips/configs/generic/board-${board}.config" + if [ ! -f "${board_cfg}" ]; then + echo "WARNING: Board config '${board_cfg}' not found" + continue + fi + + # For each line beginning with # require, cut out the field following + # it & search for that in the reference config file. If the requirement + # is not found then the subshell will exit with code 1, and we'll + # continue on to the next board. + grep -E '^# require ' "${board_cfg}" | \ + cut -d' ' -f 3- | \ + while read req; do + case ${req} in + *=y) + # If we require something =y then we check that a line + # containing it is present in the reference config. + grep -Eq "^${req}\$" "${ref_cfg}" && continue + ;; + *=n) + # If we require something =n then we just invert that + # check, considering the requirement met if there isn't + # a line containing the value =y in the reference + # config. + grep -Eq "^${req/%=n/=y}\$" "${ref_cfg}" || continue + ;; + *) + echo "WARNING: Unhandled requirement '${req}'" + ;; + esac + + [ ${print_skipped} -eq 1 ] && echo "Skipping ${board_cfg}" + exit 1 + done || continue + + # Merge this board config fragment into our final config file + ./scripts/kconfig/merge_config.sh \ + -m -O ${objtree} ${cfg} ${board_cfg} \ + | grep -Ev '^(#|Using)' +done