populate_sdk_ext: split copy_buildsystem() into logical steps defined as functions

copy_buildsystem() has become far too large and needs to be split
into shorter and more understandable pieces; some of those
pieces will be reused for the purpose of providing esdk mode
directly from a plain yocto build.

(From OE-Core rev: a163b8f339f32bc9e3865736af321190bc89c61b)

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes-recipe/populate_sdk_ext.bbclass

@@ -186,12 +186,7 @@ def create_filtered_tasklist(d, sdkbasepath, tasklistfile, conf_initpath):
         if os.path.exists(localconf + '.bak'):
             os.replace(localconf + '.bak', localconf)
 
-python copy_buildsystem () {
+def copy_bitbake_and_layers(d, baseoutpath, derivative):
-    import re
-    import shutil
-    import glob
-    import oe.copy_buildsystem
-
     oe_init_env_script = d.getVar('OE_INIT_ENV_SCRIPT')
 
     conf_bbpath = ''
@@ -200,13 +195,7 @@ python copy_buildsystem () {
 
     # Copy in all metadata layers + bitbake (as repositories)
     buildsystem = oe.copy_buildsystem.BuildSystem('extensible SDK', d)
-    baseoutpath = d.getVar('SDK_OUTPUT') + '/' + d.getVar('SDKPATH')
 
-    #check if custome templateconf path is set
-    use_custom_templateconf = d.getVar('SDK_CUSTOM_TEMPLATECONF')
-
-    # Determine if we're building a derivative extensible SDK (from devtool build-sdk)
-    derivative = (d.getVar('SDK_DERIVATIVE') or '') == '1'
     if derivative:
         workspace_name = 'orig-workspace'
     else:
@@ -231,6 +220,9 @@ python copy_buildsystem () {
     d.setVar('oe_init_build_env_path', conf_initpath)
     d.setVar('esdk_tools_path', esdk_tools_path)
 
+    return (conf_initpath, conf_bbpath, core_meta_subdir, sdkbblayers)
+
+def write_devtool_config(d, baseoutpath, conf_bbpath, conf_initpath, core_meta_subdir):
     # Write out config file for devtool
     import configparser
     config = configparser.ConfigParser()
@@ -247,10 +239,12 @@ python copy_buildsystem () {
     with open(os.path.join(baseoutpath, 'conf', 'devtool.conf'), 'w') as f:
         config.write(f)
 
+def write_unlocked_sigs(d, baseoutpath):
     unlockedsigs =  os.path.join(baseoutpath, 'conf', 'unlocked-sigs.inc')
     with open(unlockedsigs, 'w') as f:
         pass
 
+def write_bblayers_conf(d, baseoutpath, sdkbblayers):
     # Create a layer for new recipes / appends
     bbpath = d.getVar('BBPATH')
     env = os.environ.copy()
@@ -279,6 +273,9 @@ python copy_buildsystem () {
         f.write('    $' + '{SDKBASEMETAPATH}/workspace \\\n')
         f.write('    "\n')
 
+def copy_uninative(d, baseoutpath):
+    import shutil
+
     # Copy uninative tarball
     # For now this is where uninative.bbclass expects the tarball
     if bb.data.inherits_class('uninative', d):
@@ -288,6 +285,12 @@ python copy_buildsystem () {
         bb.utils.mkdirhier(uninative_outdir)
         shutil.copy(uninative_file, uninative_outdir)
 
+    return uninative_checksum
+
+def write_local_conf(d, baseoutpath, derivative, core_meta_subdir, uninative_checksum):
+    #check if custome templateconf path is set
+    use_custom_templateconf = d.getVar('SDK_CUSTOM_TEMPLATECONF')
+
     env_passthrough = (d.getVar('BB_ENV_PASSTHROUGH_ADDITIONS') or '').split()
     env_passthrough_values = {}
 
@@ -457,6 +460,9 @@ python copy_buildsystem () {
                 f.write(line)
             f.write('\n')
 
+def prepare_locked_cache(d, baseoutpath, derivative, conf_initpath):
+    import shutil
+
     # Filter the locked signatures file to just the sstate tasks we are interested in
     excluded_targets = get_sdk_install_targets(d, images_only=True)
     sigfile = d.getVar('WORKDIR') + '/locked-sigs.inc'
@@ -560,6 +566,9 @@ python copy_buildsystem () {
                 f = os.path.join(root, name)
                 os.remove(f)
 
+def write_manifest(d, baseoutpath):
+    import glob
+
     # Write manifest file
     # Note: at the moment we cannot include the env setup script here to keep
     # it updated, since it gets modified during SDK installation (see
@@ -583,6 +592,32 @@ python copy_buildsystem () {
                     continue
                 chksum = bb.utils.sha256_file(fn)
                 f.write('%s\t%s\n' % (chksum, os.path.relpath(fn, baseoutpath)))
+
+
+python copy_buildsystem () {
+    import oe.copy_buildsystem
+
+    baseoutpath = d.getVar('SDK_OUTPUT') + '/' + d.getVar('SDKPATH')
+
+    # Determine if we're building a derivative extensible SDK (from devtool build-sdk)
+    derivative = (d.getVar('SDK_DERIVATIVE') or '') == '1'
+
+    conf_initpath, conf_bbpath, core_meta_subdir, sdkbblayers = copy_bitbake_and_layers(d, baseoutpath, derivative)
+
+    write_devtool_config(d, baseoutpath, conf_bbpath, conf_initpath, core_meta_subdir)
+
+    write_unlocked_sigs(d, baseoutpath)
+
+    write_bblayers_conf(d, baseoutpath, sdkbblayers)
+
+    uninative_checksum = copy_uninative(d, baseoutpath)
+
+    write_local_conf(d, baseoutpath, derivative, core_meta_subdir, uninative_checksum)
+
+    prepare_locked_cache(d, baseoutpath, derivative, conf_initpath)
+
+    write_manifest(d, baseoutpath)
+
 }
 
 def get_current_buildtools(d):