Hi guys, I just got my dlink dir-615 up and running with openwrt 23.05.2, for those who are trying to accomplish the same I will make a short tutorial
First thing, backup your flash, I used a ch341a because it's easier for me, you can also backup the flash using your existing openwrt installation.
I removed all the system partitions (removed: nvram, mac, lp) and left only the u-boot, firmware and art, so you won't be able to return to the original firmware if you don't make a backup.
For the 16mb I used the Winbond 25Q128FV, the RAM is from a old 512mb DDR ram with the flash chip marked as K4H511638F-TCCC.
Now for the tutorial:
1- Flash the "breed-ar724x-reset12.bin" from breed u-boot
2- Flash the sysupdate.bin of my custom openwrt firmware in the breed uboot web interface and use the layout as TPLINK
3- Enable custom environments variable (see breed uboot manual)
4- telnet into uboot telnet 192.168.1.1 and type the command env set autoboot.command "boot flash 0x20000"
NOTE: the firmware has luci installed and the kmod-tun, all others kmods are avaliable in the .zip file
The system now has 9MB of free storage and a lot of RAM
