The initramfs image can be generated by building openwrt with CONFIG_TARGET_ROOTFS_INITRAMFS option enabled manually.
(On other targets (like ramips), there's the "initramfs" feature-flag that enables this by default. But enabling it for just one device is a bit "meh". Port more devices and there is maybe a case.)
First - thank you very much for the quick reply and pointing us in the right direction!
I'm afraid this exceeds a bit my skills and setup right now. I got donated a few of those devices and was hoping to turn them to dummy APs as give-aways. I'm finding those days kids and parents quite appreciate such gifts!
Even despite being limited to 1x1 it is still a good and usable device. It's a pity to have to throw it away.
I understand that this might be a rather inefficient thing to do but if someone could do a one-time build with all the necessary files (enough to convert the device the first time) I would much appreciate the help!
Please no. Don't give MR32s away as "gifts". Especially AP-devices (the MX64 routers do at least have some use without a WIFI) really need a WIFI driver for their main radios before they are even remotely useful. There are much better "give-away devices" like the WNDR3700. they "just work" and hence are much better ambassadors.
Also, Cisco Meraki has an active interest in making sure there's no alternative firmware for second hand market for their devices. A bunch of MR33 (the MR32 successor) were bricked because of that:
Heh . This went almost as well as expected for that target, you see what you are up against... Well, you don't know it, but the initramfs are build before the images are being done. So check your /home/owrt/openwrtbin/targets/bcm53xx/generic/ for the openwrt-bcm53xx-generic-meraki_mr32-initramfs.bin. This is that mr32-initramfs.bin .
(Maybe CONFIG_TARGET_INITRAMFS_COMPRESSION_LZMA=y needs to be enabled as well. But from what I remember the MR32 uses kexec and it wouldn't boot
smaller images. We'll see.)
owrt@osboxes:~/openwrt$ find . -name *initramfs.bin
./bin/targets/bcm53xx/generic/openwrt-bcm53xx-generic-smartrg_sr400ac-initramfs.bin
./bin/targets/bcm53xx/generic/openwrt-bcm53xx-generic-meraki_mr32-initramfs.bin
./build_dir/target-arm_cortex-a9_musl_eabi/linux-bcm53xx_generic/tmp/openwrt-bcm53xx-generic-smartrg_sr400ac-initramfs.bin
./build_dir/target-arm_cortex-a9_musl_eabi/linux-bcm53xx_generic/tmp/openwrt-bcm53xx-generic-meraki_mr32-initramfs.bin
owrt@osboxes:~/openwrt$ ls -la ./bin/targets/bcm53xx/generic/openwrt-bcm53xx-generic-meraki_mr32-initramfs.bin
-rw-r--r-- 1 owrt owrt 10362880 Dec 13 00:37 ./bin/targets/bcm53xx/generic/openwrt-bcm53xx-generic-meraki_mr32-initramfs.bin
owrt@osboxes:~/openwrt$ ls -la ./build_dir/target-arm_cortex-a9_musl_eabi/linux-bcm53xx_generic/tmp/openwrt-bcm53xx-generic-meraki_mr32-initramfs.bin
-rw-r--r-- 1 owrt owrt 10362880 Dec 13 00:37 ./build_dir/target-arm_cortex-a9_musl_eabi/linux-bcm53xx_generic/tmp/openwrt-bcm53xx-generic-meraki_mr32-initramfs.bin
owrt@osboxes:~/openwrt$
I also see "openwrt-bcm53xx-generic-meraki_mr32-squashfs.sysupgrade.bin" in the same folder.
It seems "./bin/targets" is where all the output went to (and the two files seem identical).
For the record - version.buildinfo says: r15204-b2d48c1dfe
I guess I'll give it a shot and report - hopefully all working!
First thing first:
I Have 6 MR32 waiting to be freed from Meraki...
From now on what i managed to get is this, after hours of compiling:
3 Files:
openwrt-bcm53xx-generic-meraki_mr32.manifest
openwrt-bcm53xx-generic-meraki_mr32-initramfs.bin
openwrt-bcm53xx-generic-meraki_mr32-squashfs.sysupgrade.bin
(if you need one of thoose file i can upload it somewhere for you.
I have a FTDI232 USB adaptator and succesfully connected it to the Meraki MR32.
While booting, the MR32 is giving me a lot of informations via Putty such as this uboot version:
U-Boot 2012.10-00075-g79231c6
Now i need some help to get the next steps. I'll be happy to test anything if someone knows what i should do.
Thanks! I learned a lot with this article.
Sadly i think i won't be able to go further. After reading this article : https://snt.sh/2016/02/pwning-the-meraki-mr18/ , i found out that my firmware version was: 25-201807091103-G1dfc8e26-aacharya
So, if i understood it well, i won't be able to root my devices unless there is a way to downgrade?
I tried to press reset for 10 sec., but every time a reboot occurs the answers to commands such as
odm serial_num read
are : UNRECOGNIZED COMMAND LOGGED TO CLOUD SERVERS