as discussed in OpenWrt 19.07.10 service release @MangoMan tested "https://anonfiles.com/ceAfM62dy1/openwrt-ramips-rt305x-unbranded_wr512-3gn-4m-squashfs-sysupgrade_bin" but imagebuilder "https://anonfiles.com/n4A0M827yc/openwrt-imagebuilder-ramips-rt305x.Linux-x86_64.tar_xz" seems broken (needs more work)
If anyone is interested here's latest 21.02-snapshot images for rt305x 4M devices:
https://maurerr.github.io/openwrt-21.02-rt305x-4M/
BusyBox v1.33.2 (2022-08-08 06:56:57 UTC) built-in shell (ash)
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|__| W I R E L E S S F R E E D O M
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OpenWrt 21.02-SNAPSHOT, r16628-fdb59e128d
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root@OpenWrt:~#
I flashed via luci from 19.07.10 and kept the settings 
thanks - I'll work a bit on imagebuilder as I see that's failing on my side then publish all 4m image in a web folder
Simply awesome and great work! You are a magician I must admit 
Any particular reason the image is even smaller than the ones I created with 19.07.x and all suggested package removals? Shouldn't a 21.02.x image be bigger already because of the kernel? 
Is it because all this optimizations here:
It's awesome because it's like 250k smaller means it should be a ease to include some packages with image builder directly 
Thank's a million for taking time pushing the good old ralinks on another level
all magic thanks goes to @Ashus for his config that I almost copy-pasted 
Can confirm this (used the imagebuilder from your github link), tried for different targets (wr512-3gn-4m, a5-v11, mpr-a1) but all fail with this output in the end:
* opkg_install_cmd: Cannot install package kmod-ledtrig-netdev.
* opkg_install_cmd: Cannot install package kmod-usb-core.
* opkg_install_cmd: Cannot install package kmod-usb-ohci.
* opkg_install_cmd: Cannot install package kmod-usb2.
* opkg_install_cmd: Cannot install package opkg.
* opkg_install_cmd: Cannot install package uhttpd-mod-ubus.
* opkg_install_cmd: Cannot install package ca-bundle.
* opkg_install_cmd: Cannot install package kmod-usb-ohci.
* opkg_install_cmd: Cannot install package kmod-usb2.
* opkg_install_cmd: Cannot install package libustream-wolfssl.
* opkg_install_cmd: Cannot install package opkg.
* opkg_install_cmd: Cannot install package wpad-basic-wolfssl.
make[2]: *** [Makefile:167: package_install] Error 255
make[1]: *** [Makefile:122: _call_image] Error 2
make: *** [Makefile:240: image] Error 2
Is there anything I (just a user no programmer 
) could help with getting the imagebuilder working?
Because now there is not only plenty of free flash (compared to 19.x) but it is also the only way to add extra packages now (as OPKG is removed). Would be awesome to add some extra more functionality (adblocker etc.) and get the most out of this little warriors 
Well I spent some time on it last week but couldn't get it fully running. I'll restart my day job tomorrow so I'll probably have some time to work on this as well. Just don't get your hopes up as @Ashus s builds lack imagebuilder as well so probably some deep error
Good to know - wasn't aware of that at all. So I guess you are building the images then directly from "source" - right?
Would it be a very time consuming task for you to create a round of images with adblock and travelmate already included? 
Sorry, I'm not i to "customization business" but you could always grab the sources via git (v21.02 branch) and download my config.buildinfo and save it as .config and add everything you need via make menuconfig then fillow the rest of the build procedure (or just run "make")
git clone https://git.openwrt.org/openwrt/openwrt.git
git checkout openwrt-21.02
wget https://maurerr.github.io/openwrt-21.02-rt305x-4M/config.buildinfo
mv config.buildinfo .config
and then for up2date packages I run these scripts:
./scripts/feeds update -a
./scripts/feeds install -a
It's compiling... hope my computer survives it
Apparently my machine is still alive but the outcome wasn't satisfying:
make[2] package/install
make[2] target/install
make[3] -C target/linux install
ERROR: target/linux failed to build.
make -r world: build failed. Please re-run make with -j1 V=s or V=sc for a higher verbosity level to see what's going on
make: *** [/home/builder/openwrt-21.02-rt305x-4M/openwrt/include/toplevel.mk:230: world] Error 1
but checking the bin/targets/ directories some images were actually build:
-rw-r--r-- 1 builder builder 31944 ago 28 18:32 config.buildinfo
-rw-r--r-- 1 builder builder 288 ago 28 18:32 feeds.buildinfo
-rw-r--r-- 1 builder builder 3814162 ago 28 19:29 openwrt-ramips-rt305x-7links_px-4885-4m-initramfs-kernel.bin
-rw-r--r-- 1 builder builder 3814103 ago 28 19:29 openwrt-ramips-rt305x-airlive_air3gii-initramfs-kernel.bin
-rw-r--r-- 1 builder builder 3813960 ago 28 19:30 openwrt-ramips-rt305x-allnet_all0256n-4m-initramfs-kernel.bin
-rw-r--r-- 1 builder builder 3813972 ago 28 19:30 openwrt-ramips-rt305x-asiarf_awapn2403-initramfs-kernel.bin
-rw-r--r-- 1 builder builder 3830052 ago 28 19:30 openwrt-ramips-rt305x-asiarf_awapn2403-squashfs-sysupgrade.bin
-rw-r--r-- 1 builder builder 3814101 ago 28 19:30 openwrt-ramips-rt305x-asiarf_awm002-evb-4m-initramfs-kernel.bin
-rw-r--r-- 1 builder builder 3813908 ago 28 19:30 openwrt-ramips-rt305x-asus_rt-g32-b1-initramfs-kernel.bin
-rw-r--r-- 1 builder builder 3830048 ago 28 19:30 openwrt-ramips-rt305x-asus_rt-g32-b1-squashfs-sysupgrade.bin
-rw-r--r-- 1 builder builder 3813959 ago 28 19:30 openwrt-ramips-rt305x-asus_rt-n10-plus-initramfs-kernel.bin
-rw-r--r-- 1 builder builder 3814019 ago 28 19:30 openwrt-ramips-rt305x-asus_wl-330n3g-initramfs-kernel.bin
-rw-r--r-- 1 builder builder 3830048 ago 28 19:30 openwrt-ramips-rt305x-asus_wl-330n3g-squashfs-sysupgrade.bin
-rw-r--r-- 1 builder builder 3813998 ago 28 19:30 openwrt-ramips-rt305x-asus_wl-330n-initramfs-kernel.bin
-rw-r--r-- 1 builder builder 3830042 ago 28 19:30 openwrt-ramips-rt305x-asus_wl-330n-squashfs-sysupgrade.bin
-rw-r--r-- 1 builder builder 3814057 ago 28 19:30 openwrt-ramips-rt305x-aztech_hw550-3g-initramfs-kernel.bin
-rw-r--r-- 1 builder builder 3932449 ago 28 19:30 openwrt-ramips-rt305x-aztech_hw550-3g-squashfs-sysupgrade.bin
-rw-r--r-- 1 builder builder 3814060 ago 28 19:30 openwrt-ramips-rt305x-buffalo_whr-g300n-initramfs-kernel.bin
drwxr-xr-x 2 builder builder 12288 ago 28 19:22 packages
-rw-r--r-- 1 builder builder 18 ago 28 18:32 version.buildinfo
looks like it failed at b... to bad as my devices are mostly at the end of the alphabet 
Via menuconfig select only your devices
Did this and for one device I got no -sysupgrade.bin (only kernel and manifest) but for the other one a sysupgrade popped out. I just then uploaded the result over my 19.07.10 and with keep settings but the result wasn't the usual I'm spoiled with Meaning the configured wifi AP didn't spawn and I lost access to the device for now.... (it is the one which does not feature the easy serial access 
)
So I gained access (using the ethernet port that previously was configured as wan port) because by the looks of it the settings weren't kept.
But doesn't look like it's doing really well actually - that is what's presented as web page:
and it stays the same after issuing a firstboot via ssh (which works and presents itself as OpenWrt 21.02:
BusyBox v1.33.2 (2022-08-28 06:33:46 UTC) built-in shell (ash)
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|_______|| __|_____|__|__||________||__| |____|
|__| W I R E L E S S F R E E D O M
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OpenWrt 21.02-SNAPSHOT, r16638-4cb9d08e71
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not much space left in the overlay
root@OpenWrt:~# df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 3.0M 3.0M 0 100% /rom
tmpfs 14.0M 56.0K 14.0M 0% /tmp
/dev/mtdblock6 36.0K 32.0K 4.0K 89% /overlay
overlayfs:/overlay 36.0K 32.0K 4.0K 89% /
tmpfs 512.0K 0 512.0K 0% /dev
one top
Mem: 21892K used, 6860K free, 64K shrd, 2168K buff, 5508K cached
CPU: 0% usr 1% sys 0% nic 98% idle 0% io 0% irq 0% sirq
Load average: 0.00 0.09 0.09 1/39 1987
PID PPID USER STAT VSZ %VSZ %CPU COMMAND
1987 1978 root R 1228 4% 1% top
1977 948 root S 1164 4% 1% /usr/sbin/dropbear -F -P /var/run/dropbear.1.pid -p 22 -K 300 -T 3
747 1 root S 1888 7% 0% /sbin/rpcd -s /var/run/ubus/ubus.sock -t 30
1109 1 root S 1728 6% 0% /sbin/netifd
1047 1 root S 1708 6% 0% /usr/sbin/wpa_supplicant -n -s -g /var/run/wpa_supplicant/global
1046 1 root S 1708 6% 0% /usr/sbin/hostapd -s -g /var/run/hostapd/global
1 0 root S 1612 6% 0% /sbin/procd
1241 1 root S 1464 5% 0% /usr/sbin/odhcpd
1795 1 dnsmasq S 1360 5% 0% /usr/sbin/dnsmasq -C /var/etc/dnsmasq.conf.cfg01411c -k -x /var/run/dnsmasq/dnsmasq.cfg01411c.pid
1348 1 root S 1360 5% 0% /usr/sbin/uhttpd -f -h /www -r OpenWrt -x /cgi-bin -t 60 -T 30 -k 20 -A 1 -n 3 -N 100 -R -p 0.0.0.0:80 -p [::]:80
695 1 logd S 1264 4% 0% /sbin/logd -S 64
410 1 ubus S 1248 4% 0% /sbin/ubusd
1746 1539 root S 1236 4% 0% -ash
1978 1977 root S 1236 4% 0% -ash
1976 1746 root S 1228 4% 0% top
1537 1 root S< 1228 4% 0% /usr/sbin/ntpd -n -N -S /usr/sbin/ntpd-hotplug -p 0.openwrt.pool.ntp.org -p 1.openwrt.pool.ntp.org -p 2.openwrt.pool.ntp.org -p 3.openwrt.pool.ntp.o
1539 948 root S 1168 4% 0% /usr/sbin/dropbear -F -P /var/run/dropbear.1.pid -p 22 -K 300 -T 3
948 1 root S 1104 4% 0% /usr/sbin/dropbear -F -P /var/run/dropbear.1.pid -p 22 -K 300 -T 3
445 1 root S 1044 4% 0% /sbin/urngd
411 1 root S 940 3% 0% /sbin/askfirst /usr/libexec/login.sh
4 2 root IW< 0 0% 0% [kworker/0:0H-ev]
44 2 root IW 0 0% 0% [kworker/0:1-eve]
7 2 root SW 0 0% 0% [ksoftirqd/0]
5 2 root IW 0 0% 0% [kworker/u2:0-ev]
198 2 root SW 0 0% 0% [spi0]
368 2 root SWN 0 0% 0% [jffs2_gcd_mtd6]
49 2 root IW 0 0% 0% [kworker/u2:4-ev]
524 2 root IW< 0 0% 0% [cfg80211]
267 2 root IW< 0 0% 0% [ipv6_addrconf]
272 2 root IW< 0 0% 0% [kworker/0:1H]
96 2 root IW< 0 0% 0% [kblockd]
92 2 root IW< 0 0% 0% [writeback]
94 2 root SW 0 0% 0% [kcompactd0]
105 2 root SW 0 0% 0% [watchdogd]
6 2 root IW< 0 0% 0% [mm_percpu_wq]
8 2 root SW 0 0% 0% [oom_reaper]
2 0 root SW 0 0% 0% [kthreadd]
3 2 root IW 0 0% 0% [kworker/0:0-eve]
129 2 root SW 0 0% 0% [kswapd0]
no idea what the problem is - maybe the stuff I build from source wasn't done right?
maybe using a stable tag git checkout tags/v21.02.3 would produce a stable build ?
Unfortunately I haven't had progress in producing a usable imagebuilder so I don't think I'll waste any more time on this
Thanks, works great on the a5-v11 unbranded (£10 amazon device)
Hello!
Thank you! Your 21.02 build works great on my unbranded/ralink WR512 (4M) which is only available for the 8M version in the firmware selector!
My device has USB so I wonder if extROOT (like 22.03.3 tiny official(!) imagebuilder configuration for 4/32MB devices (ath79, TL-WA860RE v1 etc.), using ramdisk extroot maybe) can be used so it does not have space limiations?
Also I see the release is from august last year - is their anything I can do for a newer release?
Thank's again for your work which helps reducing e-waste and running our (working) devices longer in save manner!
see the steps in [testing] 21.02 for rt305x 4MB devices - #11 by MangoMan
you need to ask the maintainer - i have no idea
I would avoid wrestling with 4/32. My TL-WA860RE started crashing with OOM after some uptime, so in addition to being a lot of work, it's also not stable.