[OE-core][PATCH v2 1/2] package_manager/ipk: skip checksums for unsigned local feeds

[ecordonnier@snap.com]

From: Etienne Cordonnier <ecordonnier@snap.com>

Computing checksums in the opkg Packages index requires reading every
.ipk file in full.  For a large image with 7000+ packages (including
multi-gigabyte debug packages), this adds 150-300s to every do_rootfs run.

Checksums in the Packages index are only meaningful for signed feeds
(PACKAGE_FEED_SIGN=1): the GPG signature covers the Packages index
which contains the SHA256Sum of each .ipk, forming a chain of trust
that prevents tampered packages being swapped on a remote feed.

For unsigned local file:// feeds the packages are installed directly
from the build host filesystem where there is no tampering risk.  Skip
all checksum generation in that case by passing no --checksum flags to
opkg-make-index (the tool's default behaviour when given no flags).
Pass --force-checksum to opkg so it does not error on the absent
checksum fields.

On a test image with 7000+ packages (including a 2.3 GB debug
package): write_index time reduced from ~180s to ~22s (8x speedup)
when opkg-make-index is configured to produce no checksums by default.

See https://git.openembedded.org/openembedded-core/commit/?id=e462f47489f35902b6972f9837d9adfa542fc796
("Enable sha256 checksums in opkg indexer", 2019) for the original rationale.

AI-Generated: Claude Sonnet 4.6
Signed-off-by: Etienne Cordonnier <ecordonnier@snap.com>
---
 meta/lib/oe/package_manager/ipk/__init__.py | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/meta/lib/oe/package_manager/ipk/__init__.py b/meta/lib/oe/package_manager/ipk/__init__.py
index 344e0852177..93a12fad6a3 100644
--- a/meta/lib/oe/package_manager/ipk/__init__.py
+++ b/meta/lib/oe/package_manager/ipk/__init__.py
@@ -12,7 +12,7 @@ from oe.package_manager import *
 from oe.package_manager.common_deb_ipk import OpkgDpkgPM
 
 class OpkgIndexer(Indexer):
-    def write_index(self):
+    def write_index(self, build_checksums=True):
         arch_vars = ["ALL_MULTILIB_PACKAGE_ARCHS",
                      "SDK_PACKAGE_ARCHS",
                      ]
@@ -44,8 +44,9 @@ class OpkgIndexer(Indexer):
                 if not os.path.exists(pkgs_file):
                     open(pkgs_file, "w").close()
 
-                index_cmds.add('%s --checksum md5 --checksum sha256 -r %s -p %s -m %s %s' %
-                                  (opkg_index_cmd, pkgs_file, pkgs_file, pkgs_dir, opkg_index_cmd_extra_params))
+                checksum_args = '--checksum md5 --checksum sha256 ' if build_checksums else ''
+                index_cmds.add('%s %s-r %s -p %s -m %s %s' %
+                                  (opkg_index_cmd, checksum_args, pkgs_file, pkgs_file, pkgs_dir, opkg_index_cmd_extra_params))
 
                 index_sign_files.add(pkgs_file)
 
@@ -103,8 +104,12 @@ class OpkgPM(OpkgDpkgPM):
         self.deploy_dir = oe.path.join(self.d.getVar('WORKDIR'), ipk_repo_workdir)
         self.deploy_lock_file = os.path.join(self.deploy_dir, "deploy.lock")
         self.opkg_cmd = bb.utils.which(os.getenv('PATH'), "opkg")
+        self.from_feeds = (self.d.getVar('BUILD_IMAGES_FROM_FEEDS') or "") == "1"
+        self._build_checksums = self.from_feeds or self.d.getVar('PACKAGE_FEED_SIGN') == '1'
         self.opkg_args = ['--volatile-cache', '-f', config_file, '-t', self.d.expand('${T}/ipktemp/'), '-o', target_rootfs]
         self.opkg_args.extend(shlex.split(self.d.getVar("OPKG_ARGS")))
+        if not self._build_checksums:
+            self.opkg_args.append('--force-checksum')
 
         if prepare_index:
             create_packages_dir(self.d, self.deploy_dir, d.getVar("DEPLOY_DIR_IPK"), "package_write_ipk", filterbydependencies)
@@ -116,7 +121,6 @@ class OpkgPM(OpkgDpkgPM):
         if not os.path.exists(self.d.expand('${T}/saved')):
             bb.utils.mkdirhier(self.d.expand('${T}/saved'))
 
-        self.from_feeds = (self.d.getVar('BUILD_IMAGES_FROM_FEEDS') or "") == "1"
         if self.from_feeds:
             self._create_custom_config()
         else:
@@ -346,7 +350,7 @@ class OpkgPM(OpkgDpkgPM):
     def write_index(self):
         self.deploy_dir_lock()
 
-        result = self.indexer.write_index()
+        result = self.indexer.write_index(build_checksums=self._build_checksums)
 
         self.deploy_dir_unlock()
 
-- 
2.43.0