This documents the way U-Boot understands partitions specifications. This also updates the fastboot documentation for the changes in the previous commit.
Signed-off-by: Sean Anderson sean.anderson@seco.com Reviewed-by: Simon Glass sjg@chromium.org ---
Changes in v4: - Expand documentation, making it more man-page-like
Changes in v2: - Move partition documentation under doc/usage
doc/android/fastboot.rst | 4 ++ doc/usage/index.rst | 1 + doc/usage/partitions.rst | 80 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 85 insertions(+) create mode 100644 doc/usage/partitions.rst
diff --git a/doc/android/fastboot.rst b/doc/android/fastboot.rst index 16b11399b3..ce513a2a0f 100644 --- a/doc/android/fastboot.rst +++ b/doc/android/fastboot.rst @@ -154,6 +154,10 @@ The device index starts from ``a`` and refers to the interface (e.g. USB controller, SD/MMC controller) or disk index. The partition index starts from ``1`` and describes the partition number on the particular device.
+Alternatively, partition types may be specified using :ref:`U-Boot's partition +syntax <partitions>`. This allows specifying partitions like ``0.1``, +``0#boot``, or ``:3``. The interface is always ``mmc``. + Writing Partition Table -----------------------
diff --git a/doc/usage/index.rst b/doc/usage/index.rst index 83cfbafd90..d45467caf2 100644 --- a/doc/usage/index.rst +++ b/doc/usage/index.rst @@ -6,6 +6,7 @@ Use U-Boot
fdt_overlays netconsole + partitions
Shell commands -------------- diff --git a/doc/usage/partitions.rst b/doc/usage/partitions.rst new file mode 100644 index 0000000000..cbf8ae34f1 --- /dev/null +++ b/doc/usage/partitions.rst @@ -0,0 +1,80 @@ +.. SPDX-License-Identifier: GPL-2.0+ +.. _partitions: + +Partitions +========== + +Synopsis +-------- + +:: + + <command> <interface> [devnum][.hwpartnum][:partnum|#partname] + +Description +----------- + +Many U-Boot commands allow specifying partitions (or whole disks) using a +generic syntax. + +interface + The interface used to access the partition's device, like ``mmc`` or + ``scsi``. For a full list of supported interfaces, consult the + ``if_typename_str`` array in ``drivers/block/blk-uclass.c`` + +devnum + The device number. This defaults to 0. + +hwpartnum + The hardware partition number. All devices have at least one hardware + partition. On most devices, hardware partition 0 specifies the whole + device. On eMMC devices, hardware partition 0 is the user partition, + hardware partitions 1 and 2 are the boot partitions, hardware partition + 3 is the RPMB partition, and further partitions are general-purpose + user-created partitions. The default hardware partition number is 0. + +partnum + The partition number, starting from 1. The partition number 0 specifies + that the whole device is to be used as one "partition." + +partname + The partition name. This is the partition label for GPT partitions. For + MBR partitions, the following syntax is used:: + + <devtype><devletter><partnum> + + mbr_interface + A device type like ``mmcsd`` or ``hd``. See the + ``part_set_generic_name`` function in ``disk/part.c`` for a + complete list. + + devletter + The device number as an offset from ``a``. For example, device + number 2 would have a device letter of ``c``. + + partnum + The partition number. This is the same as above. + +If neither ``partname`` nor ``partnum`` is specified and there is a partition +table, then partition 1 is used. If there is no partition table, then the whole +device is used as one "partition." If none of ``devnum``, ``hwpartnum``, +``partnum``, or ``partname`` is specified, or only ``-`` is specified, then +``devnum`` defaults to the value of the ``bootdevice`` environmental variable. + +Examples +-------- + +List the root directory contents on MMC device 2, hardware partition 1, +and partition number 3:: + + ls mmc 2.1:3 / + +Load ``/kernel.itb`` to address ``0x80000000`` from SCSI device 0, hardware partition +0, and the partition labeled ``boot``:: + + load scsi #boot 0x80000000 /kernel.itb + +Print the partition UUID of the SATA device ``$bootdevice``, hardware partition +0, and partition number 0:: + + part uuid sata -