I wonder why Firefox is not compatible with LG Optimus gt540 running Android 2.1?
I have been waiting for so long for firefox mobile, but when it was out I have been trying each version without success. All the time what I'm getting is my phone is not compatible. I'm running Android OS 2.1. I wish fire fox could be made compatible with many android devices first.
Alla svar (1)
The two main things that you need for mobile Firefox to work is Android 2.0 and newer (which you have) and the cpu on phone/tablet has to be a ARM v7 type of cpu as the old ARM v6 will not work.
The LG Optimus gt540 uses a Qualcomm MSM7227 cpu which is basically a ARMv6 http://en.wikipedia.org/wiki/LG_GT540 http://en.wikipedia.org/wiki/MSM7227#MSM7227_and_MSM7230
So in other words the mobile Firefox will not work on this phone as it requires the ARM v7 type of cpus. There were test builds for ARM v6 before but they tended to be slow and crash prone so they were stopped.