+
+Description
+-----------
+
+The gpt command lets users read, create, modify, or verify the GPT (GUID
+Partition Table) partition layout.
+
+The syntax of the text description of the partition list is similar to
+the one used by the 'mbr' command. The string contains one or more partition
Please, link the mbr page:
by the :doc:`mbr command <mbr>`.
+descriptors, each separated by a ";". Each descriptor contains one or more
+fields, with each field separated by a ",". Fields are either of the form
+"key=value" to set a specific value, or simple "flag" to set a boolean flag
At this point it remains unclear to the reader what this ;-separated
string format relates to.
Is it an output format?
Is it a format used in variables?
Is it used for the parameter 'partition string'?
Maybe describe it after the parameters and relate it to the 'partition
string' parameter.
Please, describe all parameters (in this indented format):
interface
interface for accessing the block device (mmc, sata, scsi, usb, ....)
device no
device number
...
+
+The first descriptor can optionally be used to describe parameters for the
+whole disk with the following fields:
+
+* uuid_disk=UUID - Set the UUID for the disk
+
+Partition descriptors can have the following fields:
+* name=NAME - The partition name, required
Maybe better
name=<NAME>
This is not rendered as an unordered list but everything is in one line.
Please, add the missing blank lines.
Please, generate the HTML documentation as described in
https://u-boot.readthedocs.io/en/latest/build/documentation.html
and check the output before resubmitting.
+* start=BYTES - The partition start offset in bytes, required
+* size=BYTES - The partition size, in bytes or "-" to expand it to the whole
free area
+* bootable - Set the legacy bootable flag
+* uuid=UUID - Set the partition UUID, optional if CONFIG_RANDOM_UUID=y is
enabled
+* type=UUID - Set the partition type GUID, requires
CONFIG_PARTITION_TYPE_GUID=y
+
The following should be in a separate 'Examples' section to match the
other man-pages.
+Here is an example how to create a 6 partitions, some of the predefined sizes:
+
+::
+
+ => setenv gpt_parts 'uuid_disk=bec9fc2a-86c1-483d-8a0e-0109732277d7;
+
name=boot,start=4M,size=128M,bootable,type=ebd0a0a2-b9e5-4433-87c0-68b6b72699c7,
+ name=rootfs,size=3072M,type=0fc63daf-8483-4772-8e79-3d69d8477de4;
+ name=system-data,size=512M,type=0fc63daf-8483-4772-8e79-3d69d8477de4;
+ name=[ext],size=-,type=0fc63daf-8483-4772-8e79-3d69d8477de4;
+ name=user,size=-,type=0fc63daf-8483-4772-8e79-3d69d8477de4;
+ name=modules,size=100M,type=0fc63daf-8483-4772-8e79-3d69d8477de4;
+ name=ramdisk,size=8M,type=0fc63daf-8483-4772-8e79-3d69d8477de4
+ => gpt write mmc 0 $gpt_parts
+
+
+If 'uuid' is not specified, but CONFIG_RANDOM_UUID is enabled, a random UUID
+will be generated for the partition
+
+The 'gpt verify' command returns 0 if the layout matches the one on the storage
+device or 1 if not. To check if the layout on the MMC #0 storage device
+matches the provided text description one has to issue following command:
The command can be used with and without partition parameter. This
should be described here.
I would prefer:
sets the return value $? to 0 (true) if the layout
or 1 (false) if not
+
+::
+
+ => gpt verify mmc 0 $gpt_parts
+
+The verify sub-command is especially useful in the system update scripts:
+
+::
+
+ => if gpt verify mmc 0 $gpt_parts; then
+ echo GPT layout needs to be updated
+ ...
+ fi
+
+The 'gpt write' command returns 0 on success write or 1 on failure.
+
+The 'gpt setenv' command will set a series of environment variables with
+information about a particular partition. The variables are:
+
+* gpt_partition_addr (the starting offset of the partition, in hexadecimal
blocks)
+* gpt_partition_size (the size of the partition, in hexadecimal blocks)
The blocks that are not hexadecimal, the numbers are.
gpt_partition_addr (first block of the partition as hexadecimal number)
gpt_partition_size (number of blocks as hexadecimal number)
+* gpt_partition_name (the name of the partition)
+* gpt_partition_entry (the partition number in the table, e.g. 1, 2, 3, etc.)
This value is currently decimal but this seems to be a bug. We need a
hexadecimal number to use this variable in a command like
load host 0:$gpt_partition_entry $loadaddr filename
Another bug is that this command assumes that partitions are
continuously numbered.
+
+To get the information about the partition named 'rootfs', issue the following
+command:
+
+::
+ => gpt setenv mmc 0 rootfs
+ => echo ${gpt_partition_addr}
+ 2000
+ => echo ${gpt_partition_size}
+ 14a000
+ => echo ${gpt_partition_name}
+ rootfs
+ => echo ${gpt_partition_entry}
+ 2
+
+The 'gpt enumerate' command will set the variable 'gpt_partition_list' with the
+list of partition names on the device. For example:
+
+::
+ => gpt enumerate
+ => echo gpt_partition_list
+ boot rootfs system-data [ext] user modules ramdisk
As we cannot see from the output if there is a partition 'user' and a
partition 'modules' or only a single partition 'user modules' this
sub-command seems to need some rework.