AT+CGSN how to?

[charlielao]

Can anyone help me understand AT+CGSN please?
After patching, what software/hardware do i need? I have the sync station connected to the serial port of my PC.
Also, How do i use the AT commands? If i want to find a specific RAM location of a command, for example SEND SMS command, what do i do?

[rizapn]

There are at least 2 different AT+CGSN patch(es) for SL45. The 1st, the original ones, was done by me and improved by chaos, and the 2nd was created by mamaich (I also have another one, which was published only in the asm source file). All of them have different syntax. You can read the syntax in the patch comment(s).

After patching one of them, you need HyperTerminal or any other software like that (which providing a raw connection to the serial interface --for this, you can try my capturer software or the ones created by Acid--). Normally, you need to set the s/w baudrate to 19200, but if you patch your phone using mamaich patch, you can increase the speed to 57600.

Then, you can type any modified AT+CGSN command to do some RAM and firmware test that you need. But, for sure, if you want to find: a specific RAM location of a command, for example SEND SMS command, you need much-much more than only an AT+CGSN patch.

If you want to find something new in your firmware, then you will need to :
- have the disasm version of the whole firmware,
- have the alias (routine/function name) for any founded routines in the firmware (for example strcpy, memcpy, etc-etc),
- have the string list of any predefined text in the firmware, and also the images and its ID,
- if your needed is already founded by others for other firmware, sometimes, comparing the bytecode is work 100%, but if it is not comparable, then at least it help us by getting the ideas,
- insert some "debugging" patch(es) to trace/proove our guess,
- have very much idle time, and get some luck

rizapn

[charlielao]

Thank you for the reply MASTER. But now i think ive asked for a question with an answer i cant handle

[lalo.lerry]

@MASTER:
It's exactly what I've done/I'm doing each time I create a new patch, and what I said to my student long time ago via MSN...

Just one note:
all above is not enought if not applied with cleverness and tested with a lot of tries... as I already said, reverse engenieering and patching is a hard (but wonderfull) mind game!