1 Broadcom TRX Container Partition 1 Broadcom TRX Container Partition
2 ================================ 2 ================================
3 3
4 TRX is Broadcom's official firmware format for 4 TRX is Broadcom's official firmware format for the BCM947xx boards. It's used by
5 most of the vendors building devices based on 5 most of the vendors building devices based on Broadcom's BCM47xx SoCs and is
6 supported by the CFE bootloader. 6 supported by the CFE bootloader.
7 7
8 Design of the TRX format is very minimalistic. 8 Design of the TRX format is very minimalistic. Its header contains
9 identification fields, CRC32 checksum and the 9 identification fields, CRC32 checksum and the locations of embedded partitions.
10 Its purpose is to store a few partitions in a 10 Its purpose is to store a few partitions in a format that can be distributed as
11 a standalone file and written in a flash memor 11 a standalone file and written in a flash memory.
12 12
13 Container can hold up to 4 partitions. The fir 13 Container can hold up to 4 partitions. The first partition has to contain a
14 device executable binary (e.g. a kernel) as it 14 device executable binary (e.g. a kernel) as it's what the CFE bootloader starts
15 executing. Other partitions can be used for op 15 executing. Other partitions can be used for operating system purposes. This is
16 useful for systems that keep kernel and rootfs 16 useful for systems that keep kernel and rootfs separated.
17 17
18 TRX doesn't enforce any strict partition bound 18 TRX doesn't enforce any strict partition boundaries or size limits. All
19 partitions have to be less than the 4GiB max s 19 partitions have to be less than the 4GiB max size limit.
20 20
21 There are two existing/known TRX variants: 21 There are two existing/known TRX variants:
22 1) v1 which contains 3 partitions 22 1) v1 which contains 3 partitions
23 2) v2 which contains 4 partitions 23 2) v2 which contains 4 partitions
24 24
25 There aren't separated compatible bindings for 25 There aren't separated compatible bindings for them as version can be trivialy
26 detected by a software parsing TRX header. 26 detected by a software parsing TRX header.
27 27
28 Required properties: 28 Required properties:
29 - compatible : (required) must be "brcm,trx" 29 - compatible : (required) must be "brcm,trx"
30 30
31 Optional properties: 31 Optional properties:
32 32
33 - brcm,trx-magic: TRX magic, if it is differen 33 - brcm,trx-magic: TRX magic, if it is different from the default magic
34 0x30524448 as a u32. 34 0x30524448 as a u32.
35 35
36 Example: 36 Example:
37 37
38 flash@0 { 38 flash@0 {
39 partitions { 39 partitions {
40 compatible = "brcm,trx"; 40 compatible = "brcm,trx";
41 }; 41 };
42 }; 42 };
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