I've tried a usb2demon device on a QSB board and it doesn't work at all.
I've seen that QSB board have a 1,8V ref tension on its jtag connector (pin 1) and usb2demon is waiting for a tension going from 2.2 to 5 V. Do you think it could be the problem.
What's the type of Macraigor's device used with imx53qsb ?
Macraigor Systems will have a demo of our Usb2Demon and Eclipse Indigo/gnutools running on the iMX53 Quick Start board at ESC San Jose this week (tuesday - thursday).
Some of our old ARM20 Usb2Demons were built with drivers that only supported 2.5V and higher. If you need one that supports the lower voltage value. Email me at email@example.com and we will exchange your unit for the newer lower voltage version.
I suggest you to contact the JTAG tool manufacturer. Macraigor is used to work with Freescale product.
In the meantime, I would replace R157 by a 0ohm instead of the default 100ohm which is actually not necessary. That avoids an additional slight voltage drop for the reference.
I actually don't have a very good experience with Macraigor JTAG/BDMs under Linux, but other people may differ. For the iMX535QSB, I started using SEGGER J-link for ARM www.segger.com/jlink.html and it works great under both Linux and Windows. It did not support iMX535 out of the box, but it does update its firmware when connected. After the firmware update it worked just fine.