[gnome-continuous-yocto/gnomeostree-3.28-rocko: 435/8267] classes/kernel: check OLDEST_KERNEL at configure time

[Emmanuele Bassi <ebassi src gnome org>]

commit 55159ef0567c9c5f47609a18cff8866a17e53173
Author: Paul Eggleton <paul eggleton linux intel com>
Date:   Mon May 9 16:43:31 2016 +1200

    classes/kernel: check OLDEST_KERNEL at configure time
    
    If the kernel being built is older than OLDEST_KERNEL and we're building
    with glibc, then the C library we're building is probably not going to
    be compatible with the kernel and we should warn the user. (This is
    easier to do here rather than when building glibc, because we don't
    necessarily have the information we need to determine the kernel version
    there, whereas we do here.)
    
    Fixes [YOCTO #8653].
    
    (From OE-Core rev: 2e66f57febe85a63ce2ab98eaf6318d47eb60939)
    
    Signed-off-by: Paul Eggleton <paul eggleton linux intel com>
    Signed-off-by: Ross Burton <ross burton intel com>
    Signed-off-by: Richard Purdie <richard purdie linuxfoundation org>

 meta/classes/kernel.bbclass |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)
---
diff --git a/meta/classes/kernel.bbclass b/meta/classes/kernel.bbclass
index 75450ce..c5355cf 100644
--- a/meta/classes/kernel.bbclass
+++ b/meta/classes/kernel.bbclass
@@ -326,6 +326,20 @@ sysroot_stage_all () {
 
 KERNEL_CONFIG_COMMAND ?= "oe_runmake_call -C ${S} O=${B} oldnoconfig || yes '' | oe_runmake -C ${S} O=${B} 
oldconfig"
 
+python check_oldest_kernel() {
+    oldest_kernel = d.getVar('OLDEST_KERNEL', True)
+    kernel_version = d.getVar('KERNEL_VERSION', True)
+    tclibc = d.getVar('TCLIBC', True)
+    if tclibc == 'glibc':
+        kernel_version = kernel_version.split('-', 1)[0]
+        if oldest_kernel and kernel_version:
+            if bb.utils.vercmp_string(kernel_version, oldest_kernel) < 0:
+                bb.warn('%s: OLDEST_KERNEL is "%s" but the version of the kernel you are building is "%s" - 
therefore %s as built may not be compatible with this kernel. Either set OLDEST_KERNEL to an older version, 
or build a newer kernel.' % (d.getVar('PN', True), oldest_kernel, kernel_version, tclibc))
+}
+
+check_oldest_kernel[vardepsexclude] += "OLDEST_KERNEL KERNEL_VERSION"
+do_configure[prefuncs] += "check_oldest_kernel"
+
 kernel_do_configure() {
        # fixes extra + in /lib/modules/2.6.37+
        # $ scripts/setlocalversion . => +