Selective Booting using an internal variable

Hi I am working with the ADSP-21489 and following the EE-345 application note. On the example in EE-345, case 1 approach 1, it does load a differnent application, but using the FLAG0 pin.

My question is, is there a way to boot different applications, depending on a value stored in an external E2PROM memory? Or bootloader restricted size will not allow me to do that and I will need to use a SSL?

Thanks in advance.