Purpose: Boot section sizes and Flash address ranges.

Namespace: atmega2560::bootloader.

The ATmega2560 provides four boot section sizes: 512, 1,024, 2,048, or 4,096 words. The BOOTSZ1:0 fuse bits select the active partition.

#include <atmega2560/Bootloader.h>
 
namespace mcu = atmega2560;
 
static_assert(mcu::bootloader::SectionSizeWords::Words512 == static_cast<mcu::bootloader::SectionSizeWords>(512), "ATmega2560 boot size");
static_assert(static_cast<unsigned>(mcu::bootloader::BootSizeCode::Words512) == 0x03, "ATmega2560 BOOTSZ code");
static_assert(mcu::bootloader::smallest_boot_start_word_address == 0x1FE00UL, "ATmega2560 smallest boot section");
static_assert(mcu::bootloader::largest_boot_start_word_address == 0x1F000UL, "ATmega2560 largest boot section");

Boot partition

Addresses below are Flash word addresses, not byte addresses. Each Flash page contains 128 words.

BOOTSZ1:0	Boot size	Pages	Application end	Boot start	Boot end
11	512 words	4	0x1FDFF	0x1FE00	0x1FFFF
10	1,024 words	8	0x1FBFF	0x1FC00	0x1FFFF
01	2,048 words	16	0x1F7FF	0x1F800	0x1FFFF
00	4,096 words	32	0x1EFFF	0x1F000	0x1FFFF

The boot section size and start address are selected by BOOTSZ1:0; the library does not configure the fuses.

These are hardware definitions, not runtime register access or initialization.

Source: ATmega2560 datasheet (DS40002211A), Table 29-13.