1Broadcom BCM47xx Partitions
2===========================
3
4Broadcom is one of hardware manufacturers providing SoCs (BCM47xx) used in
5home routers. Their BCM947xx boards using CFE bootloader have several partitions
6without any on-flash partition table. On some devices their sizes and/or
7meanings can also vary so fixed partitioning can't be used.
8
9Discovering partitions on these devices is possible thanks to having a special
10header and/or magic signature at the beginning of each of them. They are also
11block aligned which is important for determinig a size.
12
13Most of partitions use ASCII text based magic for determining a type. More
14complex partitions (like TRX with its HDR0 magic) may include extra header
15containing some details, including a length.
16
17A list of supported partitions includes:
181) Bootloader with Broadcom's CFE (Common Firmware Environment)
192) NVRAM with configuration/calibration data
203) Device manufacturer's data with some default values (e.g. SSIDs)
214) TRX firmware container which can hold up to 4 subpartitions
225) Backup TRX firmware used after failed upgrade
23
24As mentioned earlier, role of some partitions may depend on extra configuration.
25For example both: main firmware and backup firmware use the same TRX format with
26the same header. To distinguish currently used firmware a CFE's environment
27variable "bootpartition" is used.
28
29
30Devices using Broadcom partitions described above should should have flash node
31with a subnode named "partitions" using following properties:
32
33Required properties:
34- compatible : (required) must be "brcm,bcm947xx-cfe-partitions"
35
36Example:
37
38flash@0 {
39	partitions {
40		compatible = "brcm,bcm947xx-cfe-partitions";
41	};
42};
43