# Compiling to specific glibc version with mkapp **URL:** \ **Category:** Uncategorized\ **Created:** [August 21, 2020, 6:14am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369 "2020-08-21T06:14:29Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![ClaudioBaldo](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@ClaudioBaldo](https://forum.legato.io/u/ClaudioBaldo)\ **Post date:** [August 21, 2020, 6:14am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/1 "2020-08-21T06:14:29Z")
I am trying to implement a json-c library as an application and I have a problem with the glibc version. This is the toolchain I am using for the wp77xx (FX30S) /opt/swi/SWI9X06Y\_02.32.02.00/sysroots/x86\_64-pokysdk-linux/usr/bin/arm-poky-linux-gnueabi This is instead the repo for the json-c library: > **[GitHub - json-c/json-c: https://github.com/json-c/json-c is the official code...](https://github.com/json-c/json-c)** > > https://github.com/json-c/json-c is the official code repository for json-c. See the wiki for release tarballs for download. API docs at http://json-c.github.io/json-c/ - GitHub - json-c/json-c: ... The problem I have is that I can make the app and to upload it to the target, but then it doesn`t run because it requests a newer version of GLIBC 2.25 while I have a 2.24 uploaded in the target. Sorry if this is a silly question, but I have been looking into this for the whole day trying to link the older version of the GLIBC library, but is this set by the toolchain or by the json-c library? Anyone knows where the version of the GLIBC gets assigned? Because I would expect the toolchain to compile using the suitable GLIBC library… ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [August 21, 2020, 6:31am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/2 "2020-08-21T06:31:06Z")
you can try with Ubuntu 18.04: owner@ubuntu:~$ ldd --version ldd (Ubuntu GLIBC 2.27-3ubuntu1) 2.27 Copyright (C) 2018 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Written by Roland McGrath and Ulrich Drepper. owner@ubuntu:~$ lsb\_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu Bionic Beaver (development branch) Release: 18.04 Codename: bionic owner@ubuntu:~$ ---
**Author:** ![ClaudioBaldo](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@ClaudioBaldo](https://forum.legato.io/u/ClaudioBaldo)\ **Post date:** [August 21, 2020, 7:14am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/3 "2020-08-21T07:14:44Z")
I am using ubuntu 20 on a VM but… \*\*\*\*\*@\*\*\*\*-VirtualBox:~/mySystemAws$ ldd --version ldd (Ubuntu GLIBC 2.31-0ubuntu9) 2.31 Copyright (C) 2020 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Written by Roland McGrath and Ulrich Drepper. So the GLIBC version in my VM is 2.31 but the code is compiled for 2.25, this is why I was wondering if this is set somewhere (maybe in automatic) but the compiler once it compiles the files… ---
**Author:** ![ClaudioBaldo](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@ClaudioBaldo](https://forum.legato.io/u/ClaudioBaldo)\ **Post date:** [August 21, 2020, 7:51am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/4 "2020-08-21T07:51:17Z")
this is the error I get when trying to run the application: Aug 21 07:47:44 fx30s user.err Legato: =ERR= | handleJSON[5079] | handleJSON: /lib/libc.so.6: version `GLIBC\_2.25’ not found (required by /lib/libComponent\_handleJSONComponent.so) and I am assuming this is set somewhere by the toolchain not the VM machine toolchain or I would get an error saying that the version GLIBC\_2.31 is required not the 2.25, correct. The toolchain must set the required GLIBC library as it compiles the json-c library, because I don`t get this message when I compile and deploy the app I have generated for connecting to AWS. So my question was, how can I get the toolchain to compile the app to a specific GLIBC verstion? (2.24) ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [August 21, 2020, 7:57am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/5 "2020-08-21T07:57:57Z")
do you think you can downgrade your GLIBC to have a try? ---
**Author:** ![ClaudioBaldo](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@ClaudioBaldo](https://forum.legato.io/u/ClaudioBaldo)\ **Post date:** [August 21, 2020, 8:04am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/6 "2020-08-21T08:04:44Z")
you mean to downgrade the GLIBC of ubuntu 20.04 from 2,31 to 2,24? ---
**Author:** ![ClaudioBaldo](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@ClaudioBaldo](https://forum.legato.io/u/ClaudioBaldo)\ **Post date:** [August 21, 2020, 8:37am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/7 "2020-08-21T08:37:01Z")
downgrading the glibc is a quite dangerous task, that also means that I cannot use a newer OS to compile code for an older target, which basically goes against the whole purpose of cross compiling… Did I understand correctly what you have asked me to do? Are you sure this is the problem? ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [August 21, 2020, 9:09am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/9 "2020-08-21T09:09:31Z")
what is the GLIBC version on your target? On my side with FX30 FX9.1: root@fx30:~# strings /legato/systems/current/appsWriteable/hello1/lib/libc.so.6 | grep GLIBC GLIBC\_2.4 GLIBC\_2.5 GLIBC\_2.6 GLIBC\_2.7 GLIBC\_2.8 GLIBC\_2.9 GLIBC\_2.10 GLIBC\_2.11 GLIBC\_2.12 GLIBC\_2.13 GLIBC\_2.14 GLIBC\_2.15 GLIBC\_2.16 GLIBC\_2.17 GLIBC\_2.18 GLIBC\_2.22 GLIBC\_2.23 GLIBC\_2.24 GLIBC\_PRIVATE I have also tried to find the lib version inside the toolchain of WP76 R13: owner@owner-ThinkPad-X220:/opt/swi/SWI9X07Y\_02.28.03.01$ strings ./sysroots/armv7a-neon-poky-linux-gnueabi/lib/libc.so.6 | grep GLIB GLIBC\_2.4 GLIBC\_2.5 GLIBC\_2.6 GLIBC\_2.7 GLIBC\_2.8 GLIBC\_2.9 GLIBC\_2.10 GLIBC\_2.11 GLIBC\_2.12 GLIBC\_2.13 GLIBC\_2.14 GLIBC\_2.15 GLIBC\_2.16 GLIBC\_2.17 GLIBC\_2.18 GLIBC\_2.22 GLIBC\_2.23 GLIBC\_2.24 GLIBC\_2.25 GLIBC\_2.26 GLIBC\_2.27 GLIBC\_PRIVATE Not sure if you can find a more updated WP77 toolchain to compile your app. (Or you can take the one in WP76 R13 toolchain and paste to the target /lib/libc.so.6?) As /lib is read-only, you might need to overlay it: root@fx30:~# mkdir /tmp/tmp\_lib;mkdir /tmp/tmp\_lib\_wr; root@fx30:~# mount -t overlay overlay /lib -o lowerdir=/lib,upperdir=/tmp/tmp\_li b,workdir=/tmp/tmp\_lib\_wr; ---
**Author:** ![ClaudioBaldo](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@ClaudioBaldo](https://forum.legato.io/u/ClaudioBaldo)\ **Post date:** [August 24, 2020, 2:44am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/10 "2020-08-24T02:44:02Z")
I don`t know what is included in the image for this fs, but when I make the folders and copy the libc.so.6 into the tmp\_lib, then run the overlay command I get this error: root@fx30s:/tmp# mount -t overlay overlay /lib -o lowerdir=/lib,upperdir=/tmp/tmp\_lib,workdir=/tmp/tmp\_lib\_wr; root@fx30s:/tmp# app start handleJSON **app: relocation error: /lib/libc.so.6: symbol \_dl\_exception\_create, version GLIBC\_PRIVATE not defined in file ld-linux.so.3 with link time reference** ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [August 24, 2020, 3:04am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/11 "2020-08-24T03:04:33Z")
maybe you also need to copy the ld-linux.so.3: owner@owner-ThinkPad-X220:~/Downloads$ find /opt/swi/SWI9X07Y\_02.28.03.01/sysroots/armv7a-neon-poky-linux-gnueabi/ -name “ld-linux.so.3” /opt/swi/SWI9X07Y\_02.28.03.01/sysroots/armv7a-neon-poky-linux-gnueabi/lib/ld-linux.so.3 owner@owner-ThinkPad-X220:~/Downloads$ strings /opt/swi/SWI9X07Y\_02.28.03.01/sysroots/armv7a-neon-poky-linux-gnueabi/lib/ld-linux.so.3 | grep GLIB GLIBC\_2.4 GLIBC\_PRIVATE GLIBC\_TUNABLES ---
**Author:** ![ClaudioBaldo](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@ClaudioBaldo](https://forum.legato.io/u/ClaudioBaldo)\ **Post date:** [August 24, 2020, 3:44am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/12 "2020-08-24T03:44:37Z")
mmmhhh… It doesn`t seems we are getting anywhere here, maybe the best option at this point is to rebuild the image of my target with all necessary libraries, which I would have preferred to do at a later stage but I don`t see any alternative if I want to move forward… ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [August 24, 2020, 3:57am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/13 "2020-08-24T03:57:09Z")
To me, no idea why your /lib/libComponent\_handleJSONComponent.so will require a GLIBC lib that is not present on your toolchain. I wonder if you are using the correct toolchain path to compile your app… Anyway, good luck! ---
**Author:** ![ClaudioBaldo](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@ClaudioBaldo](https://forum.legato.io/u/ClaudioBaldo)\ **Post date:** [August 24, 2020, 4:43am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/14 "2020-08-24T04:43:12Z")
well, I don`t know either, this was the reason why I posted on this forum… 🙂 The problem is certainly the toolchain, which is building the app with a newer Glibc library then what is included in the firmware. The only toolchain I can find is the one from this link: [https://source.sierrawireless.com/resources/airprime/software/wp77xx/wp77xx-firmware-latest-release-components/#sthash.AFozzBQj.dpbs](https://source.sierrawireless.com/resources/airprime/software/wp77xx/wp77xx-firmware-latest-release-components/#sthash.AFozzBQj.dpbs) **poky-swi-ext-glibc-x86\_64-meta-toolchain-swi-armv7a-neon-toolchain-swi-SWI9X06Y\_02.35.02.00.sh** you said this should be the correct one instead: wp77-toolchain\_SWI9X06Y\_02.18.05.00-linux64 So where can I find this toolchain…??? ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [August 24, 2020, 4:55am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/15 "2020-08-24T04:55:42Z")
you can search by “leaf search” and then you will see a identifier "swi-fx30-catm\_1.0.0 " ---
**Author:** ![ClaudioBaldo](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@ClaudioBaldo](https://forum.legato.io/u/ClaudioBaldo)\ **Post date:** [August 24, 2020, 5:03am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/16 "2020-08-24T05:03:23Z")
that is the firmware not the toolchain, correct? ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [August 24, 2020, 5:24am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/17 "2020-08-24T05:24:29Z")
it includes the toolchain, legato framework, images. ---
**Author:** ![ClaudioBaldo](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@ClaudioBaldo](https://forum.legato.io/u/ClaudioBaldo)\ **Post date:** [August 24, 2020, 5:37am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/18 "2020-08-24T05:37:36Z")
I have been working with a manual installation of the legato workspace and that could have been the problem, I was more looking to replace and re-install the toolchain still working merely under legato but I can use leaf instead. The problem I have is that after installing the leaf: XXXX@XXXX-VirtualBox:~/leaf/AwsProject$ leaf status ┌─────────────────────────────────────────────────────────────────────────────────────────┐ │ Workspace: /home/XXXX/leaf/AwsProject │ ╞═════════════════════════════════════════════════════════════════════════════════════════╡ │ Profile: FX30S\_stable [current] (sync) │ ├──────────┬─────────────────────┬────────────────────────────────────────────────────────┤ │ Packages │ Identifier │ Description │ ├──────────┼─────────────────────┼────────────────────────────────────────────────────────┤ │ Included │ swi-fx30-catm\_1.0.0 │ SDK for FX30-CATM (Release 9.1.1.013 + Legato 18.06.1) │ └──────────┴─────────────────────┴───────────────────── I still don`t have access to the commands (mkapp, mksys) which I get if I configure the environment under legato workspace: XXXX@XXXX-VirtualBox:~/legatoWorkspace/legatoAF$ source bin/configlegatoenv which should technically use the installed toolchain… So my question is, do I need to remove the currently installed toolchain I have manually installed when using leaf or this will adjust to the required toolchain? (I would expect the former but something is not working at the moment). ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [August 24, 2020, 5:50am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/19 "2020-08-24T05:50:14Z")
you can type “export” to check if the toolchain path is correct after you do “. bin/configlegatoenv” e.g. ![image](https://us1.discourse-cdn.com/flex019/uploads/legato1/original/1X/326e0d28122ffb75c927462bd4720e76774a89eb.png) ---
**Author:** ![ClaudioBaldo](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@ClaudioBaldo](https://forum.legato.io/u/ClaudioBaldo)\ **Post date:** [August 24, 2020, 5:55am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/20 "2020-08-24T05:55:58Z")
this is what I read once I have setup the leaf under the leaf workspace (which is different from the legato workspace) and then run the source bin/configlegatoenv in the legato workspace. declare -x WP77XX\_KERNELROOT=“/opt/swi/SWI9X07Y\_02.28.03.05/sysroots/armv7a-neon-poky-linux-gnueabi/usr/src/kernel” declare -x WP77XX\_SYSROOT=“/opt/swi/SWI9X07Y\_02.28.03.05/sysroots/armv7a-neon-poky-linux-gnueabi” declare -x WP77XX\_TOOLCHAIN\_DIR=“/opt/swi/SWI9X07Y\_02.28.03.05/sysroots/x86\_64-pokysdk-linux/usr/bin/arm-poky-linux-gnueabi” declare -x WP77XX\_TOOLCHAIN\_PREFIX=“arm-poky-linux-gnueabi-” the bin folder is installed by the toolchain manual install so something is still not clear. ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.legato.io/jyijyi/32/822_2.png) [@jyijyi](https://forum.legato.io/u/jyijyi)\ **Post date:** [August 24, 2020, 5:57am UTC](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369/21 "2020-08-24T05:57:44Z")
seems it is not using the toolchain you installed. [Next page](https://forum.legato.io/t/compiling-to-specific-glibc-version-with-mkapp/5369.md?page=2)