Re: [lime-users] Repository packages compatibility and kernel vermagic [was: opkg install]

TL;DR to compile a LibreMesh image compatible with all the packages from OpenWrt repositories is possible and easy. Long (and messy) version: It should definitely be possible to use the packages on the OpenWrt repository when compiling a tagged (and released) version. So I did a bit of research on this. The kernel shipped with OpenWrt 19.07.3 has version number: 4.14.180-1-2e88863ccdd594fb8e842df3c25842ee but the one compiled following the instructions on our website has version number (check it using "opkg info kernel"): 4.14.180-1-5e4cae9b310636f0484e8ed34f1b94b0 as you can see, the kernel version is the same but what changes is the last part. **This string at the end of the version is a hash of the options used for compiling the kernel.** This means that even if the version is the same, when we select some of the LibreMesh packages which activate some functions in the kernel, we make our image incompatible with part (only the packages which are related somehow to the kernel, like tc) of OpenWrt's repositories. Some good information can be found here: https://forum.openwrt.org/t/compiling-image-with-same-kernel-as-the-repos/4… and here: https://forum.openwrt.org/t/kernel-version-incompatible/59784/6 and most importantly here: https://openwrt.org/docs/guide-developer/build-system/use-buildsystem#compi… The hash of the configuration gets calculated here: https://github.com/openwrt/openwrt/blob/4791afa734d4754cd92c65feffc60e62e4d… and in my case (compiling for YouHua WR1200JS) refers to this file: build_dir/target-mipsel_24kc_musl/linux-ramips_mt7621/linux-4.14.180/.config.set So, the compilation should be done starting from the config.buildinfo present in the OpenWrt repository in https://downloads.openwrt.org/releases/[stable release]/targets/[architecture]/[target]/config.buildinfo and after this, the packages we select should not set kernel options. And neither their dependencies. The downside is that the compilation takes much longer and 9 GB of additional disk space. Instead of starting from the full config.buildinfo, I tested which are the lines which actually cause a kernel version change (in case you wanted to try, a fast way to generate the .config.set from the .config is using the command "make target/linux/compile"). This is the bare minimum .config (at least when compiling for ramips) for having the correct kernel vermagic: CONFIG_ALL_KMODS=y CONFIG_DEVEL=y # CONFIG_KERNEL_KALLSYMS is not set CONFIG_KERNEL_BUILD_DOMAIN="buildhost" CONFIG_KERNEL_BUILD_USER="builder" You can set these options in the menuconfig (inside the "Global build settings" menu) or (maybe easier?) start from a .config file with only these lines and then select target (which router to compile for) and packages (like selecting LibreMesh packages). Going this way, I obtained a kernel with the right options, which therefore should be compatible with all the packages in OpenWrt's repositories. Ciao! Ilario PS we have other settings in our packages that do not change the kernel configuration but create an image which has some features which images created with official image builder (SDK) cannot contain. Are these options really needed in LibreMesh? bmx7-auto-gw-bw-mode/Makefile: CONFIG_BUSYBOX_CONFIG_CROND bmx7-auto-gw-bw-mode/Makefile: CONFIG_BUSYBOX_CONFIG_CRONTAB bmx7-mdns/Makefile: CONFIG_BUSYBOX_CONFIG_CROND bmx7-mdns/Makefile: CONFIG_BUSYBOX_CONFIG_CRONTAB lime-debug/Makefile: select BUSYBOX_CONFIG_NC lime-debug/Makefile: select BUSYBOX_CONFIG_NC_SERVER check-date-http/Makefile: BUSYBOX_CONFIG_ASH_RANDOM_SUPPORT hotplug-initd-services/Makefile: BUSYBOX_CONFIG_ASH_RANDOM_SUPPORT shared-state-babeld_hosts/Makefile: BUSYBOX_CONFIG_ASH_RANDOM_SUPPORT shared-state-bat_hosts/Makefile: BUSYBOX_CONFIG_ASH_RANDOM_SUPPORT shared-state-dnsmasq_hosts/Makefile: BUSYBOX_CONFIG_ASH_RANDOM_SUPPORT shared-state-nodes_and_links/Makefile: BUSYBOX_CONFIG_ASH_RANDOM_SUPPORT shared-state-pirania/Makefile: BUSYBOX_CONFIG_ASH_RANDOM_SUPPORT

If these are really needed, can we ask upstream OpenWrt to have them activated by default in the next releases? On 8/30/20 7:29 PM, SAn via lime-users wrote: modules for example) are forced to depend to exactly the same kernel with exactly the same configuration. So using a different kernel version or config will raise a "invalid version", that was what happened. That is beacause the openwrt feed had one version but you compiled another version of the kernel. OpenWRT 18.06) packages but I http://downloads.openwrt.org/releases/18.06-SNAPSHOT/packages/mips_24kc/lib…, http://downloads.openwrt.org/releases/18.06-SNAPSHOT/packages/mips_24kc/lib…, http://snapshots.libremesh.org/packages/mips_24kc/libremesh/Packages.gz, instead I edited drawbacks not that's tag: [2]. clean clean way. 19.07, just https://libremesh.org/development.html#compiling_libremesh_from_source_code program I I will "opkg http://downloads.openwrt.org/releases/18.06.8/packages/mips_24kc/libremap/P…, http://downloads.openwrt.org/releases/18.06.8/packages/mips_24kc/libremesh/…, http://snapshots.libremesh.org/packages/mips_24kc/libremesh/Packages.gz, http://downloads.openwrt.org/releases/18.06.8/packages/mips_24kc/base/tc_4.… dependencies http://downloads.openwrt.org/releases/19.07.3/packages/mips_24kc/libremap/P…, http://downloads.openwrt.org/releases/19.07.3/packages/mips_24kc/libremesh/…, http://snapshots.libremesh.org/packages/mips_24kc/libremesh/Packages.gz, http://downloads.openwrt.org/releases/19.07.3/packages/mips_24kc/base/tc_5.… dependencies programs, -- Ilario iochesonome(a)gmail.com ilario(a)sindominio.net _______________________________________________ lime-users mailing list lime-users(a)lists.libremesh.org https://lists.libremesh.org/mailman/listinfo/lime-users