步驟如下：
$ cd
$ sudo dd if=/dev/sdX of=sd_mbr.img bs=1M count=20
$ od -A d -t x1 sd_mbr.img | grep '1f 8b 08'
3145792 1f 8b 08 00 00 00 00 00 02 03 ec bd 0d 78 5c d5
7340096 1f 8b 08 00 00 00 00 00 02 03 ec bd 0f 74 1c d5
$ dd if=sd_mbr.img of=head bs=1 count=3145792
3145792+0 records in
3145792+0 records out
3145792 bytes (3.1 MB, 3.0 MiB) copied, 6.86742 s, 458 kB/s
$ dd if=sd_mbr.img of=body bs=1 skip=3145792
17825728+0 records in
17825728+0 records out
17825728 bytes (18 MB, 17 MiB) copied, 38.0227 s, 469 kB/s
$ file body
body: gzip compressed data, max compression, from Unix, original size modulo 2^32 0
$ zcat body > body_ext
gzip: body: decompression OK, trailing garbage ignored
$ strings body_ext | grep Linux
Linux version 3.10.14 (root@avrman-virtual-machine) (gcc version 5.2.0 (Ingenic r3.2.0-gcc520 2017.08-24) ) #141 PREEMPT Mon Oct 16 06:09:56 EDT 2023
No init found. Try passing init= option to kernel. See Linux Documentation/init.txt for guidance.
Linux
[%s] Warning! Received an indication that the LUN assignments on this target have changed. The Linux SCSI layer does not automatically remap LUN assignments.
Warning! Received an indication that the LUN assignments on this target have changed. The Linux SCSI layer does not automatically remap LUN assignments.
[%s] Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automatically adjust these parameters.
Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automatically adjust these parameters.
6Advanced Linux Sound Architecture Driver Initialized.
Advanced Linux Sound Architecture Driver Version k%s.
Linux