package/linux-headers: add support for fetching from custom tarball/git

Add support for building toolchains against custom headers. Allows
the selection of a manual version, custom tarball or custom git
repository for the kernel headers. This enables toolchains to be
built against custom kernel headers without having to build a full
kernel.

This is particularly useful for new architectures, such as RISC-V
where updated kernel headers may not have made it into the mainline
kernel yet.

Signed-off-by: Mark Corbin <mark.corbin@embecosm.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

diff --git a/package/linux-headers/Config.in.host b/package/linux-headers/Config.in.host
index 53f684b452945ad4d8b45ed06b0b10e4fd2fb524..b12ea6986cf723839196c7132be570d6ce3c02aa 100644 (file)
--- a/package/linux-headers/Config.in.host
+++ b/package/linux-headers/Config.in.host
@@ -70,6 +70,23 @@ config BR2_KERNEL_HEADERS_VERSION
          URL at kernel.org. Instead, select "Custom tarball" and
          specify the right URL directly.
 
+config BR2_KERNEL_HEADERS_CUSTOM_TARBALL
+       bool "Custom tarball"
+       help
+         This option allows you to specify a URL pointing to a kernel
+         source tarball. This URL can use any protocol recognized by
+         Buildroot, like http://, ftp://, file:// or scp://.
+
+         When pointing to a local tarball using file://, you may want
+         to use a make variable like $(TOPDIR) to reference the root of
+         the Buildroot tree.
+
+config BR2_KERNEL_HEADERS_CUSTOM_GIT
+       bool "Custom Git repository"
+       help
+         This option allows Buildroot to get the Linux kernel source
+         code from a Git repository.
+
 endchoice
 
 config BR2_DEFAULT_KERNEL_VERSION
@@ -79,9 +96,27 @@ config BR2_DEFAULT_KERNEL_VERSION
          Specify the version you want to use.
          E.G.: 3.6.10
 
+config BR2_KERNEL_HEADERS_CUSTOM_TARBALL_LOCATION
+       string "URL of custom kernel tarball"
+       depends on BR2_KERNEL_HEADERS_CUSTOM_TARBALL
+
+if BR2_KERNEL_HEADERS_CUSTOM_GIT
+
+config BR2_KERNEL_HEADERS_CUSTOM_REPO_URL
+       string "URL of custom repository"
+
+config BR2_KERNEL_HEADERS_CUSTOM_REPO_VERSION
+       string "Custom repository version"
+       help
+         Revision to use in the typical format used by
+         Git/Mercurial/Subversion E.G. a sha id, a tag, branch, ..
+
+endif
+
 choice
        bool "Custom kernel headers series"
-       depends on BR2_KERNEL_HEADERS_VERSION || BR2_KERNEL_HEADERS_AS_KERNEL
+       depends on BR2_KERNEL_HEADERS_VERSION || BR2_KERNEL_HEADERS_AS_KERNEL || \
+                  BR2_KERNEL_HEADERS_CUSTOM_TARBALL || BR2_KERNEL_HEADERS_CUSTOM_GIT
        help
          Specify the kernel headers series you manually selected,
          above.
@@ -260,3 +295,6 @@ config BR2_DEFAULT_KERNEL_HEADERS
        default "4.16.18"       if BR2_KERNEL_HEADERS_4_16
        default "4.18.9"        if BR2_KERNEL_HEADERS_4_18
        default BR2_DEFAULT_KERNEL_VERSION if BR2_KERNEL_HEADERS_VERSION
+       default "custom"        if BR2_KERNEL_HEADERS_CUSTOM_TARBALL
+       default BR2_KERNEL_HEADERS_CUSTOM_REPO_VERSION \
+               if BR2_KERNEL_HEADERS_CUSTOM_GIT

diff --git a/package/linux-headers/linux-headers.mk b/package/linux-headers/linux-headers.mk
index 994bd627ba454658f3ad54674be75977faae09c7..45e17688c54c4e5874c2a10a81122035a6bf80b2 100644 (file)
--- a/package/linux-headers/linux-headers.mk
+++ b/package/linux-headers/linux-headers.mk
@@ -18,13 +18,13 @@ LINUX_HEADERS_VERSION = $(call qstrip,$(BR2_LINUX_KERNEL_VERSION))
 LINUX_HEADERS_CUSTOM_TARBALL_LOCATION = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_TARBALL_LOCATION))
 LINUX_HEADERS_REPO_URL = $(call qstrip,$(BR2_LINUX_KERNEL_CUSTOM_REPO_URL))
 else # ! BR2_KERNEL_HEADERS_AS_KERNEL
-LINUX_HEADERS_CUSTOM_TARBALL =
-LINUX_HEADERS_CUSTOM_GIT =
+LINUX_HEADERS_CUSTOM_TARBALL = $(call qstrip,$(BR2_KERNEL_HEADERS_CUSTOM_TARBALL))
+LINUX_HEADERS_CUSTOM_GIT = $(call qstrip,$(BR2_KERNEL_HEADERS_CUSTOM_GIT))
 LINUX_HEADERS_CUSTOM_HG =
 LINUX_HEADERS_CUSTOM_SVN =
 LINUX_HEADERS_VERSION = $(call qstrip,$(BR2_DEFAULT_KERNEL_HEADERS))
-LINUX_HEADERS_CUSTOM_TARBALL_LOCATION =
-LINUX_HEADERS_REPO_URL =
+LINUX_HEADERS_CUSTOM_TARBALL_LOCATION = $(call qstrip,$(BR2_KERNEL_HEADERS_CUSTOM_TARBALL_LOCATION))
+LINUX_HEADERS_REPO_URL = $(call qstrip,$(BR2_KERNEL_HEADERS_CUSTOM_REPO_URL))
 endif # BR2_KERNEL_HEADERS_AS_KERNEL
 
 # Configure tarball filenames.
@@ -90,7 +90,7 @@ LINUX_HEADERS_POST_PATCH_HOOKS += LINUX_HEADERS_APPLY_LOCAL_PATCHES
 endif # BR2_KERNEL_HEADERS_AS_KERNEL
 
 # Skip hash checking for custom kernel headers.
-ifeq ($(BR2_KERNEL_HEADERS_VERSION),y)
+ifeq ($(BR2_KERNEL_HEADERS_VERSION)$(BR2_KERNEL_HEADERS_CUSTOM_TARBALL)$(BR2_KERNEL_HEADERS_CUSTOM_GIT),y)
 BR_NO_CHECK_HASH_FOR += $(LINUX_HEADERS_SOURCE)
 endif
 
@@ -137,7 +137,7 @@ define LINUX_HEADERS_INSTALL_STAGING_CMDS
                        headers_install)
 endef
 
-ifeq ($(BR2_KERNEL_HEADERS_VERSION)$(BR2_KERNEL_HEADERS_AS_KERNEL),y)
+ifeq ($(BR2_KERNEL_HEADERS_VERSION)$(BR2_KERNEL_HEADERS_AS_KERNEL)$(BR2_KERNEL_HEADERS_CUSTOM_TARBALL)$(BR2_KERNEL_HEADERS_CUSTOM_GIT),y)
 define LINUX_HEADERS_CHECK_VERSION
        $(call check_kernel_headers_version,\
                $(STAGING_DIR),\