Hi,
I've been playing with those routers some time ago, so I'm familiar with OpenWrt's SDK, and therefore I can confirm WRT54G is able to fit and boot OpenWrt 18.x if you are able to build your own custom firmware.
Below some info on the build I'm testing right now:
root@192.168.1.1's password:
BusyBox v1.31.0 () built-in shell (ash)
_______ ________ __
| |.-----.-----.-----.| | | |.----.| |_
| - || _ | -__| || | | || _|| _|
|_______|| __|_____|__|__||________||__| |____|
|__| W I R E L E S S F R E E D O M
-----------------------------------------------------
OpenWrt SNAPSHOT, r10356-1ffca55456
-----------------------------------------------------
root@OpenWrt:/# df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 1.1M 1.1M 0 100% /rom
tmpfs 6.2M 32.0K 6.1M 1% /tmp
tmpfs 6.2M 36.0K 6.1M 1% /tmp/root
tmpfs 512.0K 0 512.0K 0% /dev
/dev/mtdblock5 1.5M 216.0K 1.3M 14% /overlay
overlayfs:/overlay 1.5M 216.0K 1.3M 14% /
root@OpenWrt:/# ps
PID USER VSZ STAT COMMAND
1 root 1612 S /sbin/procd
2 root 0 SW [kthreadd]
3 root 0 IW [kworker/0:0]
4 root 0 IW< [kworker/0:0H]
5 root 0 IW [kworker/u2:0]
6 root 0 IW< [mm_percpu_wq]
7 root 0 SW [ksoftirqd/0]
8 root 0 SW [oom_reaper]
57 root 0 IW [kworker/u2:5]
63 root 0 IW< [writeback]
65 root 0 SW [kcompactd0]
66 root 0 IW< [crypto]
68 root 0 IW< [kblockd]
76 root 0 IW< [watchdogd]
79 root 0 IW [kworker/0:1]
113 root 0 SW [kswapd0]
246 root 0 IW< [kworker/0:1H]
281 root 0 SW [irq/12-gpio-key]
282 root 0 SW [irq/14-gpio-key]
445 root 1256 S /sbin/ubusd
456 root 1324 S /bin/ash --login
488 root 1040 S /sbin/urngd
709 root 1764 S /sbin/netifd
990 root 1080 S /usr/sbin/dropbear -F -P /var/run/dropbear.1.pid -p
1033 root 0 SWN [jffs2_gcd_mtd5]
1078 root 1316 S< /usr/sbin/ntpd -n -N -S /usr/sbin/ntpd-hotplug -p nt
1114 root 1316 R ps
root@OpenWrt:~# cat /tmp/sysinfo/model
Linksys WRT54G/GS/GL
and here is the build configuration I've used:
CONFIG_TARGET_brcm47xx=y
CONFIG_TARGET_brcm47xx_legacy=y
CONFIG_TARGET_MULTI_PROFILE=y
CONFIG_TARGET_DEVICE_brcm47xx_legacy_DEVICE_linksys-wrt54g=y
CONFIG_BUSYBOX_CUSTOM=y
CONFIG_BUSYBOX_CONFIG_ASH_OPTIMIZE_FOR_SIZE=y
# CONFIG_BUSYBOX_CONFIG_FEATURE_IPV6 is not set
CONFIG_BUSYBOX_CONFIG_FEATURE_KLOGD_KLOGCTL=y
# CONFIG_BUSYBOX_CONFIG_FEATURE_NTPD_SERVER is not set
# CONFIG_BUSYBOX_CONFIG_FEATURE_TAB_COMPLETION is not set
# CONFIG_BUSYBOX_CONFIG_INCLUDE_SUSv2 is not set
CONFIG_BUSYBOX_CONFIG_KLOGD=y
# CONFIG_BUSYBOX_CONFIG_LOGGER is not set
# CONFIG_BUSYBOX_CONFIG_SHOW_USAGE is not set
# CONFIG_BUSYBOX_CONFIG_UDHCPC is not set
# CONFIG_BUSYBOX_DEFAULT_FEATURE_IPV6 is not set
CONFIG_CLEAN_IPKG=y
# CONFIG_FEED_hass is not set
# CONFIG_FEED_luci is not set
# CONFIG_FEED_packages is not set
# CONFIG_FEED_routing is not set
# CONFIG_FEED_telephony is not set
# CONFIG_IPV6 is not set
# CONFIG_KERNEL_CRASHLOG is not set
# CONFIG_KERNEL_DEBUG_FS is not set
# CONFIG_KERNEL_IPV6 is not set
# CONFIG_KERNEL_MAGIC_SYSRQ is not set
# CONFIG_KERNEL_PRINTK_TIME is not set
CONFIG_PACKAGE_block-mount=y
# CONFIG_PACKAGE_dnsmasq is not set
# CONFIG_PACKAGE_firewall is not set
# CONFIG_PACKAGE_hostapd-common is not set
# CONFIG_PACKAGE_iptables is not set
# CONFIG_PACKAGE_iw is not set
# CONFIG_PACKAGE_iwinfo is not set
# CONFIG_PACKAGE_kmod-b43 is not set
# CONFIG_PACKAGE_kmod-b43legacy is not set
# CONFIG_PACKAGE_kmod-cfg80211 is not set
CONFIG_PACKAGE_kmod-crypto-acompress=y
CONFIG_PACKAGE_kmod-crypto-crc32c=y
CONFIG_PACKAGE_kmod-crypto-hash=y
CONFIG_PACKAGE_kmod-fs-ext4=y
# CONFIG_PACKAGE_kmod-ipt-conntrack is not set
# CONFIG_PACKAGE_kmod-ipt-core is not set
# CONFIG_PACKAGE_kmod-ipt-nat is not set
# CONFIG_PACKAGE_kmod-ipt-offload is not set
CONFIG_PACKAGE_kmod-lib-crc16=y
CONFIG_PACKAGE_kmod-lib-lz4=y
CONFIG_PACKAGE_kmod-lib-lzo=y
# CONFIG_PACKAGE_kmod-mac80211 is not set
# CONFIG_PACKAGE_kmod-nf-conntrack is not set
# CONFIG_PACKAGE_kmod-nf-flow is not set
# CONFIG_PACKAGE_kmod-nf-ipt is not set
# CONFIG_PACKAGE_kmod-nf-ipt6 is not set
# CONFIG_PACKAGE_kmod-nf-nat is not set
# CONFIG_PACKAGE_kmod-nf-reject is not set
# CONFIG_PACKAGE_kmod-ppp is not set
CONFIG_PACKAGE_kmod-zram=y
# CONFIG_PACKAGE_libip4tc is not set
# CONFIG_PACKAGE_libip6tc is not set
# CONFIG_PACKAGE_libxtables is not set
# CONFIG_PACKAGE_logd is not set
# CONFIG_PACKAGE_opkg is not set
# CONFIG_PACKAGE_ppp is not set
# CONFIG_PACKAGE_wpad-mini is not set
CONFIG_PACKAGE_zram-swap=y
CONFIG_PROCD_ZRAM_TMPFS=y
CONFIG_STRIP_KERNEL_EXPORTS=y
CONFIG_USE_MKLIBS=y
CONFIG_B43LEGACY_FW_SQUASH=y
CONFIG_B43LEGACY_FW_SQUASH_COREREVS="1,2,3,4"
CONFIG_PACKAGE_b43legacy-firmware=y
CONFIG_PACKAGE_kmod-lib-crc-ccitt=y
CONFIG_PACKAGE_libiwinfo=y
CONFIG_PACKAGE_libpthread=y
CONFIG_PACKAGE_wireless-regdb=y
I've not tested the Wireless network that much, but it does not work, and it might be related to reasons already mentioned here:
https://openwrt.org/toh/linksys/wrt54g#linksys_wrt54g_wrt54gl_and_wrt54gs
However, the router works fine so far, and if this is useful or not depends on what you wanted this old device to do. I'm going to use the gpio.
Hope this helps anybody else trying to make use of those old blue linux routers.
Best regards,
Hernán.-