Hi all!
For those interested, I can confirm that the initial image made by wingspinner for HT-TM02 works well with HT-TM01, with the proper modifications in the model version and checksum. I made a modified image based on the HT-TM02 (you can download it from here), followed the instructions in the first post of the HT-TM02 thread (I also needed to reboot the unit manually, as it didn't reboot automatically, and the result was that my HT-TM01 was running OpenWRT. I didn't try the wifi connection, but Ethernet and Luci worked correctly. The blue system LED didn't worked after OpenWRT boots up, as wingspinner predicted in the other thread.
Unfortunately, I performed a sysupgrade in Luci with the latest trunk (I think it was r44441), as I wanted to install some packages, and then I bricked my device, so I couldn't make further tests... The unit still can be used to charge devices, but when I keep the power button pressed the blue LED keeps on and OpenWRT doesn't seem to boot. Another user in the HT-TM02 thread is reporting that he also bricked his unit, so I don't know if this is related to the TM01 or if it is an issue with the latest trunk. I think I'll have to mess with my USB-serial converter to bring it back. I hope I haven't deleted the bootloader...
So, for those who want to flash OpenWRT in their HT-TM01, you can try wingspinnner initial image, but be careful with the latest trunk!
Regards,