Is the capacity of SPI boot flash changeable? Can I use other sections beside the boot code section in the SPI Boot Flash for normal reading/writing?
Please refer to section 4.4 of the FX3 boot option application note. It descries the boot image format and loaciton for each information in the .img file. You can write anything after this size in the Flash, but please note that the bootloader will always look for address zero (from the start of the slave location). If you have memory left afer the img binary, you can keep you other data there.