Following the example of the A530 page, everything that might be useful for a port of CHDK to A540 should be posted here.
Firmware info
As in the A530 case, the ver.req file works as well in this model. It shows the following:
Canon PowerShot A540 P-ID:311B PAL Firmware Ver GM1.00B No error Jan 31 2006 11:02:45
Pressing DISP returns:
Adj Ver.002.002
Note that the platform ID is almost the same as the S3 IS model: 311B vs 311A.
Other info
Maybe this could be useful in order to get the firmware dump? -> http:// wins10sh (dot) narod (dot) ru/index1.html (I wrote it that way because the spam filter didn't let me post that URL!)