The first stage bootloader starts up as a normal standalone application. Its IV must be located at the beginning of the flash, and the reset handler initializes the associated .data and .bss memory sections, like in a normal single-stage boot. A partition at the beginning of the flash should be reserved for the bootloader .text and .data sections. To do so, the linker script for the bootloader will only include the beginning of the flash memory, and that of the application will have an offset of the same size.
The bootloader and the application will be in fact built into two separate binaries. This way, the two linker scripts can have the same name for sections, and differ only by the description of the FLASH partition in the linker ...
