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-rw-r--r--Documentation/devicetree/bindings/mtd/partitions/brcm,bcm947xx-cfe-partitions.txt42
-rw-r--r--Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt37
2 files changed, 79 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mtd/partitions/brcm,bcm947xx-cfe-partitions.txt b/Documentation/devicetree/bindings/mtd/partitions/brcm,bcm947xx-cfe-partitions.txt
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+++ b/Documentation/devicetree/bindings/mtd/partitions/brcm,bcm947xx-cfe-partitions.txt
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+Broadcom BCM47xx Partitions
+===========================
+
+Broadcom is one of hardware manufacturers providing SoCs (BCM47xx) used in
+home routers. Their BCM947xx boards using CFE bootloader have several partitions
+without any on-flash partition table. On some devices their sizes and/or
+meanings can also vary so fixed partitioning can't be used.
+
+Discovering partitions on these devices is possible thanks to having a special
+header and/or magic signature at the beginning of each of them. They are also
+block aligned which is important for determinig a size.
+
+Most of partitions use ASCII text based magic for determining a type. More
+complex partitions (like TRX with its HDR0 magic) may include extra header
+containing some details, including a length.
+
+A list of supported partitions includes:
+1) Bootloader with Broadcom's CFE (Common Firmware Environment)
+2) NVRAM with configuration/calibration data
+3) Device manufacturer's data with some default values (e.g. SSIDs)
+4) TRX firmware container which can hold up to 4 subpartitions
+5) Backup TRX firmware used after failed upgrade
+
+As mentioned earlier, role of some partitions may depend on extra configuration.
+For example both: main firmware and backup firmware use the same TRX format with
+the same header. To distinguish currently used firmware a CFE's environment
+variable "bootpartition" is used.
+
+
+Devices using Broadcom partitions described above should should have flash node
+with a subnode named "partitions" using following properties:
+
+Required properties:
+- compatible : (required) must be "brcm,bcm947xx-cfe-partitions"
+
+Example:
+
+flash@0 {
+ partitions {
+ compatible = "brcm,bcm947xx-cfe-partitions";
+ };
+};
diff --git a/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt b/Documentation/devicetree/bindings/mtd/partitions/brcm,trx.txt
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+Broadcom TRX Container Partition
+================================
+
+TRX is Broadcom's official firmware format for the BCM947xx boards. It's used by
+most of the vendors building devices based on Broadcom's BCM47xx SoCs and is
+supported by the CFE bootloader.
+
+Design of the TRX format is very minimalistic. Its header contains
+identification fields, CRC32 checksum and the locations of embedded partitions.
+Its purpose is to store a few partitions in a format that can be distributed as
+a standalone file and written in a flash memory.
+
+Container can hold up to 4 partitions. The first partition has to contain a
+device executable binary (e.g. a kernel) as it's what the CFE bootloader starts
+executing. Other partitions can be used for operating system purposes. This is
+useful for systems that keep kernel and rootfs separated.
+
+TRX doesn't enforce any strict partition boundaries or size limits. All
+partitions have to be less than the 4GiB max size limit.
+
+There are two existing/known TRX variants:
+1) v1 which contains 3 partitions
+2) v2 which contains 4 partitions
+
+There aren't separated compatible bindings for them as version can be trivialy
+detected by a software parsing TRX header.
+
+Required properties:
+- compatible : (required) must be "brcm,trx"
+
+Example:
+
+flash@0 {
+ partitions {
+ compatible = "brcm,trx";
+ };
+};