User`s manual

4.5 Flash ROM

The ﬂash ROM, sometimes called the system ROM, is a 1MB, nonvolatile,

writable ROM. After the serial ROM (SROM) code initializes the EB164

system, the ﬂash ROM code prepares the system for booting. The ﬂash ROM

headers, structure, and access methods are described here.

4.5.1 Special ROM Header

The MAKEROM tool is used to place a special header on ROM image ﬁles.

The SROM allows the system (ﬂash) ROM to contain several different ROM

images, each with its own header. The header informs the SROM where to load

the image, and whether or not it has been compressed with the MAKEROM

tool. The header is optional for system ROMs containing a single image. If

the header does not exist, the complete 1MB system ﬂash ROM is loaded

and executed starting at physical address zero. Figure 4–4 shows the header

content.

Figure 4–4 Special Header Content

Validation Pattern 5A5AC3C3

0x00

31 0

MK−2306−19

Header Rev<7:0>Firmware ID<15:8>

Inverse Validation Pattern A5A53C3C

Header Size (Bytes)

Image Checksum

Image Size (Memory Footprint)

Decompression Flag

Destination Address Lower Longword

Destination Address Upper Longword

Reserved<31:16>

Flash ROM Image Size

Optional Firmware ID<31:0>

Optional Firmware ID<63:32>

Header Checksum (excluding this field)

0x04

0x08

0x0C

0x10

0x14

0x18

0x1C

0x24

0x2C

0x30

0x20

0x28

4–8 Functional Description