Create a subdirectory in /tftpboot to hold your kernel and root filesystem.
Ex: /tftpboot/unslung
Use slugtool to unpack the flash image in this directory. Create a minicom script.

 unslung.scr

 send "ip_address -l 192.168.0.2 -h 192.168.0.63"
 expect {
 "IP:" send "load -r -v -b 0x1d00000 unslung/vmlinuz"
 "at 0x01d00000\r" send "load -r -v -b 0x1000000 unslung/ramdisk.gz"
 "at 0x01000000\r" send "exec 0x1d00000"
 "Linux"  exit
 }

Enter Control-A G in minicom, and enter the script name.