brock@raspberrypi:~$ df /boot
Filesystem     1K-blocks  Used Available Use% Mounted on
/dev/mmcblk0p1     57288 14720     42568  26% /boot
brock@raspberrypi:~$ sudo dd if=/dev/mmcblk0p1 of=boot.img bs=1M
56+0 records in
56+0 records out
58720256 bytes (59 MB) copied, 7.24718 s, 8.1 MB/s
brock@raspberrypi:~$ dc
56 1024 1024 * * f
58720256
brock@raspberrypi:~$ sudo losetup -f
/dev/loop0
brock@raspberrypi:~$ sudo losetup /dev/loop0 boot.img
brock@raspberrypi:~$ ls -l /dev/loop0
brw-rw---T 1 root disk 7, 0 Mar 31 14:21 /dev/loop0
brock@raspberrypi:~$ mkdir /tmp/myboot
brock@raspberrypi:~$ sudo mount -r /dev/loop0 /tmp/myboot
brock@raspberrypi:~$ ls /tmp/myboot
bcm2708-rpi-b.dtb       config.txt     issue.txt         overlays
bcm2708-rpi-b-plus.dtb  COPYING.linux  kernel7.img       start_cd.elf
bcm2709-rpi-2-b.dtb     fixup_cd.dat   kernel.img        start.elf
bootcode.bin            fixup.dat      LICENCE.broadcom  start_x.elf
cmdline.txt             fixup_x.dat    LICENSE.oracle
brock@raspberrypi:~$ ls /boot
bcm2708-rpi-b.dtb       config.txt     issue.txt         overlays
bcm2708-rpi-b-plus.dtb  COPYING.linux  kernel7.img       start_cd.elf
bcm2709-rpi-2-b.dtb     fixup_cd.dat   kernel.img        start.elf
bootcode.bin            fixup.dat      LICENCE.broadcom  start_x.elf
cmdline.txt             fixup_x.dat    LICENSE.oracle
brock@raspberrypi:~$ exit