Any way to disable the warning screen on nuvi 2599 with firmware 8.50 (HWID 1947).
How do you find what changes should be applied in firmware?
Last edited by moddie; 15th September 2016 at 09:41 PM.
Thanks for your reply. Could you provide a little more help? I have never used IDA Pro before and I'm lost in its data. I have loaded and disassembled my firmware but I have no idea what to do from this point.
How could I locate the appropriate function and wha tto do after locating it?
In briefly looking at your firmware, it looks similar to the firmware for the Garmin Infotainment unit. They both use boost functions which I am still trying to understand. You could patch the jumptable to make case 7 (loc_2B03B8) jump to the default case as I did for the infotainment but it would likely have undesired side effects like disabling phone functionality. In case you want to try it out, patch at file offset 0x2701F7 from 0xE3 to 0x72 to make case 7 jump to default case.
How long does the warning screen display before timing out?
Last edited by moddie; 17th September 2016 at 02:27 AM.
I was looking at the firmware from the wrong device so as of yet no patches for HWID 1947.
Last edited by moddie; 19th September 2016 at 12:21 AM.
Here is one to try on HWID 1947:
At file offset 0x2F5E74 patch from 40 1C 33 D0 to 00 20 33 E0
It appears our warning page function is at sub_207541A0. This skips it and other stuff in one instance where it is being called. There are other places that call it so it may skip the warning only when there are no EULAs to agree to or on some other condition. It may also crash at startup, or have no noticeable effect. I have not looked in detail yet at the firmware.
sub_2070AA44 appears to fetch the string referenced by the dword in R1 so the following line sets up R1 to cause the "Agree" string to be loaded by sub_2070AA44.
(Mods may want to split discussion of HWID 1947 to new thread)Code:Please Login or Register to see the links
Done as suggested, thanks.