Is there an
MBR?
Get Booting File
Is this a
FAT12/16/32
partition?
Yes
No
Success
Failed
No
Read 1st sector
Is there an
active primary
FAT 12/16/32
partition?
Read partition 1st sector
Yes
Yes
No
Buffers FAT entries in FAT
Buffer
Failed
Passed
Failed
Passed
Failed
Failed
Find booting file
in the root directory
Functional Description
Figure 26-19. MMC/SD Booting, Get Booting File
26.1.7.5.7.1 Master Boot Record (MBR)
The Master Boot Record is the 1
st
sector of a memory device. It is made out of some executable code and
4 partition entries. The aim of such a structure is to be able to divide the hard disk in partitions mostly
used to boot different systems (i.e. Microsoft Windows™, Linux, …). Its structure is described in
and
. The valid partition types searched by the ROM Code are described in
.
Table 26-22. Master Boot Record Structure
Offset
Length[bytes]
Entry Description
Value
0000h
446
Optional Code
01BEh
16
Partition Table Entry
(see
01CEh
16
Partition Table Entry
(see
01DEh
16
Partition Table Entry
(see
01EEh
16
Partition Table Entry
(see
01FEh
2
Signature
AA55h
4134
Initialization
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated