The address of the BASIC cold start routine (see Compute's Mapping the Commodore 64, page 211) is well known, see for example here:

- https://www.lemon64.com/forum/viewtopic.php?t=70680&sid=3ff66caf7f5fdf2a3c2ff2ee31fc3fd8

Fixing this routine also has a great advantage for us - since it's address lies in the uppeer ROM region, it's easier to bailout
when someone tries to use our 'kernal.rom' with the original 'basic.rom'.