How to resolve the issue of OpenWrt firmware compilation being too large?

When the firmware compiled by OpenWRT is too large, you can try the following methods to solve the issue:

1. Remove unnecessary software packages: Check if the compilation configuration includes unnecessary software packages, this can be configured using the make menuconfig command. Removing unneeded software packages can reduce the size of the firmware.
2. Compressing firmware: You can try using compression tools to reduce the size of the firmware, such as using gzip or lzma tools for compression.
3. Remove unnecessary features: Check the compilation configuration for any unnecessary features, such as disabling multi-language support or removing web interfaces, in order to reduce the size of the firmware.
4. Reduce firmware partition size: By reducing the size of certain partitions in the firmware, such as the root file system, the overall firmware size can be decreased.
5. Try using a smaller file system, such as SquashFS, instead of ext4 to reduce the size of the firmware.
6. OpenWRT offers a software package trimming tool that allows users to selectively install software packages according to their needs, in order to reduce the size of the firmware.

Please note that the above methods may result in the loss or unavailability of some functions. Therefore, before proceeding with the above actions, please make sure to back up carefully and choose a method that suits your needs.