Block
0
Page
0
CIS/IDI
1
2
...
N
Block
1
Page
0
UBL Def
1
2
UBL page 1
3
UBL page 2
4
UBL page 3
5
UBL page 4
6
UBL page 5
7
UBL page 6
8
UBL page 7
9
UBL page 8
10
UBL page 9
11 UBL page 10
12 UBL page 11
13 UBL page 12
14 UBL page 13
15 UBL page 14
Block
2
Page
0
UBL page 16
1 UBL page 17
2
UBL page 18
3
UBL page 19
4
5
6
7
8
9
10
11
12
13
14
15
Block
3
Page
0
...
N
...
Block
N
Page
0
1
2
...
N
Page 0 addr
0
4
8
12
16
Number of pages in UBL
Entry point addr of UBL
UBL magic number ID
32-bits
Starting page # of UBL
Starting block # of UBL
0xA1ACED00
0x00002100
0x00000013
0x00000001
0x00000002
UBL start addr
19 pages
Block 1
Page 2
User boot loader (UBL) definition
0x0000
0x100000
0x0020
0x3FFF
0x13FFF
IVT
IRAM0
0x4000
0x781F
0x1781F
IRAM0
0x14000
0x7FFF
0x17FFF
ITCM
DTCM
Found magic number
ROM bootloader
copies UBL into
IRAM0
Then transfers control
to UBL entry point
RBL stack space
(last 32 bits reserved for block
number of valid descriptor)
www.ti.com
ARM ROM Boot Modes
Figure 11-7. ARM NAND ROM Boot Loader Example
SPRUFX7 – July 2008
Boot Modes
157