[Buildroot] [PATCH] linux: allow the selection of the architecture's default configuration
Thomas Petazzoni
thomas.petazzoni at free-electrons.com
Tue Jun 14 10:19:58 UTC 2016
To configure the Linux kernel, we currently provide two options:
1. Passing a defconfig name (for example "multi_v7"), to which we append
"_defconfig" to run "make multi_v7_defconfig".
2. Passing a path to a custom configuration file.
Unfortunately, those two possibilities do not allow to configure the
kernel when you want to use the default configuration built into the
kernel for a given architecture. For example, on ARM64, there is a
single defconfig simply called "defconfig", which you can load by
running "make defconfig".
Using the mechanism (1) above doesn't work because we append
"_defconfig" automatically.
One solution would be to change (1) and require the user to enter the
full defconfig named (i.e "multi_v7_defconfig" instead of "multi_v7"),
but we would break all existing Buildroot configurations.
So instead, we add a third option, which simply tells Buildroot to use
the default configuration for the selected architecture. In this case,
Buildroot will configure the kernel by running "make defconfig".
Cc: Naresh Kamboju <naresh.kamboju at linaro.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
---
This proposal aims at replacing:
https://patchwork.ozlabs.org/patch/616638/
https://patchwork.ozlabs.org/patch/612216/
with a solution that 1/ doesn't break existing Buildroot
configuration (which proposal 616638 was doing), and 2/ works fine even
if the architecture also provides non-default defconfigs (which was an
issue with proposal 612216).
I've marked both of these patches as Superdeded in patchwork.
---
linux/Config.in | 8 ++++++++
linux/linux.mk | 2 ++
2 files changed, 10 insertions(+)
diff --git a/linux/Config.in b/linux/Config.in
index ce55271..be6d0cc 100644
--- a/linux/Config.in
+++ b/linux/Config.in
@@ -142,6 +142,14 @@ choice
config BR2_LINUX_KERNEL_USE_DEFCONFIG
bool "Using an in-tree defconfig file"
+config BR2_LINUX_KERNEL_USE_ARCH_DEFAULT_CONFIG
+ bool "Use the architecture default configuration"
+ help
+ This option will use the default configuration for the
+ selected architecture. I.e, it is equivalent to running
+ "make ARCH=<foo> defconfig". This is useful on architectures
+ that have a single defconfig file, such as ARM64.
+
config BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG
bool "Using a custom (def)config file"
diff --git a/linux/linux.mk b/linux/linux.mk
index a751da9..fb844ef 100644
--- a/linux/linux.mk
+++ b/linux/linux.mk
@@ -206,6 +206,8 @@ LINUX_POST_PATCH_HOOKS += LINUX_TRY_PATCH_TIMECONST
ifeq ($(BR2_LINUX_KERNEL_USE_DEFCONFIG),y)
LINUX_KCONFIG_DEFCONFIG = $(call qstrip,$(BR2_LINUX_KERNEL_DEFCONFIG))_defconfig
+else ifeq ($(BR2_LINUX_KERNEL_USE_ARCH_DEFAULT_CONFIG),y)
+LINUX_KCONFIG_DEFCONFIG = defconfig
else ifeq ($(BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG),y)
LINUX_KCONFIG_FILE = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE))
endif
--
2.7.4
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