[Buildroot] [PATCH v3 2/2] randconfig: seed with BR2_RAND_PRESEED_CONFIG_FILES

[Arnout Vandecappelle (Essensium/Mind)]

Currently, randconfig is completely unusable. Instead, we use
randpackageconfig, with two use cases: in the autobuilders, and when
doing manual testing of the validity of depends/select chains. In both
cases, we actually want the possibility to explicitly select some
packages or to set a string value or to randomise between a choice or
to test bootloaders and kernels - all of this is currently impossible.

This patch adds a BR2_RAND_PRESEED_CONFIG_FILES environment variable
that can be set to a (set of) files with config options that should be
set or unset. randconfig and randpackageconfig will force these
values.

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>
Cc: "Yann E. MORIN" <yann.morin.1998 at free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
---
v3:
 - use 'cat' instead of 'cp', to support multiple files. [Yann]

v2:
 - split off the fix for legacy
 - apply to both randconfig and randpackageconfig
 - rename to BR2_RAND_PRESEED_CONFIG_FILES because it supports
   multiple files

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>
---
 Makefile | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 5bcaa77..070c2e8 100644
--- a/Makefile
+++ b/Makefile
@@ -732,6 +732,9 @@ oldconfig: $(BUILD_DIR)/buildroot-config/conf outputmakefile
 randconfig: $(BUILD_DIR)/buildroot-config/conf outputmakefile
 	@mkdir -p $(BUILD_DIR)/buildroot-config
 	@rm -f $(CONFIG_DIR)/.config.nopkg
+ifneq ($(BR2_RAND_PRESEED_CONFIG_FILES),)
+	@cat $(BR2_RAND_PRESEED_CONFIG_FILES) > $(CONFIG_DIR)/.config.nopkg
+endif
 	@grep '^config ' Config.in.legacy | \
 		while read config pkg; do \
 		echo "# $$pkg is not set" >> $(CONFIG_DIR)/.config.nopkg; done
@@ -758,6 +761,9 @@ allnoconfig: $(BUILD_DIR)/buildroot-config/conf outputmakefile
 randpackageconfig: $(BUILD_DIR)/buildroot-config/conf outputmakefile
 	@mkdir -p $(BUILD_DIR)/buildroot-config
 	@grep -v BR2_PACKAGE_ $(BR2_CONFIG) > $(CONFIG_DIR)/.config.nopkg
+ifneq ($(BR2_RAND_PRESEED_CONFIG_FILES),)
+	@grep BR2_PACKAGE_ $(BR2_RAND_PRESEED_CONFIG_FILES) >> $(CONFIG_DIR)/.config.nopkg
+endif
 	@grep '^config BR2_PACKAGE_' Config.in.legacy | \
 		while read config pkg; do \
 		echo "# $$pkg is not set" >> $(CONFIG_DIR)/.config.nopkg; done
@@ -870,13 +876,15 @@ help:
 	@echo '  oldconfig              - resolve any unresolved symbols in .config'
 	@echo '  silentoldconfig        - Same as oldconfig, but quietly, additionally update deps'
 	@echo '  olddefconfig           - Same as silentoldconfig but sets new symbols to their default value'
-	@echo '  randconfig             - New config with random answer to all options'
+	@echo '  randconfig             - New config with random answer to all options -'
+	@echo '                             options can be forced by setting BR2_RAND_PRESEED_CONFIG_FILES'
 	@echo '  defconfig              - New config with default answer to all options'
 	@echo '                             BR2_DEFCONFIG, if set, is used as input'
 	@echo '  savedefconfig          - Save current config as ./defconfig (minimal config)'
 	@echo '  allyesconfig           - New config where all options are accepted with yes'
 	@echo '  allnoconfig            - New config where all options are answered with no'
-	@echo '  randpackageconfig      - New config with random answer to package options'
+	@echo '  randpackageconfig      - New config with random answer to package options -'
+	@echo '                             options can be forced by setting BR2_RAND_PRESEED_CONFIG_FILES'
 	@echo '  allyespackageconfig    - New config where pkg options are accepted with yes'
 	@echo '  allnopackageconfig     - New config where package options are answered with no'
 ifeq ($(BR2_PACKAGE_BUSYBOX),y)
-- 
2.1.1