diff options
Diffstat (limited to 'core')
| -rw-r--r-- | core/config.mk | 43 |
1 files changed, 37 insertions, 6 deletions
diff --git a/core/config.mk b/core/config.mk index 8a5c96e..dabdfde 100644 --- a/core/config.mk +++ b/core/config.mk @@ -151,12 +151,43 @@ include $(board_config_mk) TARGET_DEVICE_DIR := $(patsubst %/,%,$(dir $(board_config_mk))) board_config_mk := -# pull in device specific kernel headers. Files should be in -# $(TARGET_DEVICE_DIR)/kernel-headers, e.g. -# $(TARGET_DEVICE_DIR)/kernel-headers/linux/ -# $(TARGET_DEVICE_DIR)/kernel-headers/media/ -# $(TARGET_DEVICE_DIR)/kernel-headers/video/ -# etc. +# The build system exposes several variables for where to find the kernel +# headers: +# TARGET_DEVICE_KERNEL_HEADERS is automatically created for the current +# device being built. It is set as $(TARGET_DEVICE_DIR)/kernel-headers, +# e.g. device/samsung/tuna/kernel-headers. This directory is not +# explicitly set by anyone, the build system always adds this subdir. +# +# TARGET_BOARD_KERNEL_HEADERS is specified by the BoardConfig.mk file +# to allow other directories to be included. This is useful if there's +# some common place where a few headers are being kept for a group +# of devices. For example, device/<vendor>/common/kernel-headers could +# contain some headers for several of <vendor>'s devices. +# +# TARGET_PRODUCT_KERNEL_HEADERS is generated by the product inheritance +# graph. This allows architecture products to provide headers for the +# devices using that architecture. For example, +# hardware/ti/omap4xxx/omap4.mk will specify +# PRODUCT_VENDOR_KERNEL_HEADERS variable that specify where the omap4 +# specific headers are, e.g. hardware/ti/omap4xxx/kernel-headers. +# The build system then combines all the values specified by all the +# PRODUCT_VENDOR_KERNEL_HEADERS directives in the product inheritance +# tree and then exports a TARGET_PRODUCT_KERNEL_HEADERS variable. +# +# The layout of subdirs in any of the kernel-headers dir should mirror the +# layout of the kernel include/ directory. For example, +# device/samsung/tuna/kernel-headers/linux/, +# hardware/ti/omap4xxx/kernel-headers/media/, +# etc. +# +# NOTE: These directories MUST contain post-processed headers using the +# bionic/libc/kernel/clean_header.py tool. Additionally, the original kernel +# headers must also be checked in, but in a different subdirectory. By +# convention, the originals should be checked into original-kernel-headers +# directory of the same parent dir. For example, +# device/samsung/tuna/kernel-headers <----- post-processed +# device/samsung/tuna/original-kernel-headers <----- originals +# TARGET_DEVICE_KERNEL_HEADERS := $(strip $(wildcard $(TARGET_DEVICE_DIR)/kernel-headers)) define validate-kernel-headers |