Rtl8196e Openwrt

Minimal config (for 4 MB flash):

CONFIG_PACKAGE_busybox=y
CONFIG_PACKAGE_dropbear=y
CONFIG_PACKAGE_firewall=y
CONFIG_PACKAGE_dnsmasq=y
CONFIG_PACKAGE_luci=y
CONFIG_PACKAGE_luci-theme-bootstrap=y

Memory tuning (for 16–32 MB RAM):

echo 4096 > /proc/sys/vm/min_free_kbytes
echo 1 > /proc/sys/vm/overcommit_memory

Use tmpfs overlay (to reduce flash writes): rtl8196e openwrt

mount -t tmpfs tmpfs /tmp/root
cp -a /overlay/* /tmp/root
mount --move /tmp/root /overlay

A) From vendor web UI (if uncompressed – rare) Memory tuning (for 16–32 MB RAM): echo 4096

B) From U-Boot (TFTP) – most reliable

C) Serial console + U-Boot – always recommended.
Pins: GND, TX, RX (3.3V level, 115200 baud). Use tmpfs overlay (to reduce flash writes): mount

Let’s say you want to add nftables (not in old SDK) or a new kernel module.