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Diffstat (limited to 'doc/usage')
| -rw-r--r-- | doc/usage/base.rst | 23 | ||||
| -rw-r--r-- | doc/usage/fdt_overlays.rst | 134 | ||||
| -rw-r--r-- | doc/usage/index.rst | 4 | ||||
| -rw-r--r-- | doc/usage/mbr.rst | 94 | ||||
| -rw-r--r-- | doc/usage/pstore.rst | 11 |
5 files changed, 265 insertions, 1 deletions
diff --git a/doc/usage/base.rst b/doc/usage/base.rst new file mode 100644 index 00000000000..db9cd4d9783 --- /dev/null +++ b/doc/usage/base.rst @@ -0,0 +1,23 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +base command +============ + +Synopsis +-------- + +:: + + base [address] + +Description +----------- + +The *base* command sets or displays the address offset used by the memory +commands *cmp, cp, md, mdc, mm, ms, mw, mwc*. + +All other commands ignore the address defined by *base*. + +address + new base address as hexadecimal number. If no value is provided, the current + value is displayed. diff --git a/doc/usage/fdt_overlays.rst b/doc/usage/fdt_overlays.rst new file mode 100644 index 00000000000..ea39713434d --- /dev/null +++ b/doc/usage/fdt_overlays.rst @@ -0,0 +1,134 @@ +.. SPDX-License-Identifier: GPL-2.0+ +.. Copyright (c) 2017, Pantelis Antoniou <pantelis.antoniou@konsulko.com> + +Device Tree Overlays +==================== + +Overlay Syntax +-------------- + +Device-tree overlays require a slightly different syntax compared to traditional +device-trees. Please refer to dt-object-internal.txt in the device-tree compiler +sources for information regarding the internal format of overlays: +https://git.kernel.org/pub/scm/utils/dtc/dtc.git/tree/Documentation/dt-object-internal.txt + +Building Overlays +----------------- + +In a nutshell overlays provides a means to manipulate a symbol a previous +device-tree or device-tree overlay has defined. It requires both the base +device-tree and all the overlays to be compiled with the *-@* command line +switch of the device-tree compiler so that symbol information is included. + +Note + Support for *-@* option can only be found in dtc version 1.4.4 or newer. + Only version 4.14 or higher of the Linux kernel includes a built in version + of dtc that meets this requirement. + +Building a binary device-tree overlay follows the same process as building a +traditional binary device-tree. For example: + +**base.dts** + +:: + + /dts-v1/; + / { + foo: foonode { + foo-property; + }; + }; + +.. code-block:: console + + $ dtc -@ -I dts -O dtb -o base.dtb base.dts + +**overlay.dts** + +:: + + /dts-v1/; + /plugin/; + / { + fragment@1 { + target = <&foo>; + __overlay__ { + overlay-1-property; + bar: barnode { + bar-property; + }; + }; + }; + }; + +.. code-block:: console + + $ dtc -@ -I dts -O dtb -o overlay.dtbo overlay.dts + +Ways to Utilize Overlays in U-Boot +---------------------------------- + +There are two ways to apply overlays in U-Boot. + +* Include and define overlays within a FIT image and have overlays + automatically applied. + +* Manually load and apply overlays + +The remainder of this document will discuss using overlays via the manual +approach. For information on using overlays as part of a FIT image please see: +doc/uImage.FIT/overlay-fdt-boot.txt + +Manually Loading and Applying Overlays +-------------------------------------- + +1. Figure out where to place both the base device tree blob and the + overlay. Make sure you have enough space to grow the base tree without + overlapping anything. + +:: + + => setenv fdtaddr 0x87f00000 + => setenv fdtovaddr 0x87fc0000 + +2. Load the base binary device-tree and the binary device-tree overlay. + +:: + + => load ${devtype} ${bootpart} ${fdtaddr} ${bootdir}/base.dtb + => load ${devtype} ${bootpart} ${fdtovaddr} ${bootdir}/overlay.dtbo + +3. Set the base binary device-tree as the working fdt tree. + +:: + + => fdtaddr $fdtaddr + +4. Grow it enough so it can encompass all applied overlays + +:: + + => fdt resize 8192 + +5. You are now ready to apply the overlay. + +:: + + => fdt apply $fdtovaddr + +6. Boot system like you would do with a traditional dtb. + +For bootm: + +:: + + => bootm ${kerneladdr} - ${fdtaddr} + +For bootz: + +:: + + => bootz ${kerneladdr} - ${fdtaddr} + +Please note that in case of an error, both the base and overlays are going +to be invalidated, so keep copies to avoid reloading. diff --git a/doc/usage/index.rst b/doc/usage/index.rst index fbb2c0481c3..6def2507663 100644 --- a/doc/usage/index.rst +++ b/doc/usage/index.rst @@ -2,7 +2,9 @@ Use U-Boot ========== .. toctree:: + :maxdepth: 1 + fdt_overlays netconsole Shell commands @@ -11,7 +13,9 @@ Shell commands .. toctree:: :maxdepth: 1 + base bootefi bootmenu button + mbr pstore diff --git a/doc/usage/mbr.rst b/doc/usage/mbr.rst new file mode 100644 index 00000000000..bddf2f612aa --- /dev/null +++ b/doc/usage/mbr.rst @@ -0,0 +1,94 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +mbr command +=========== + +Synopsis +-------- + +:: + + mbr verify [interface] [device no] [partition list] + mbr write [interface] [device no] [partition list] + +Description +----------- + +The mbr command lets users create or verify the MBR (Master Boot Record) +partition layout based on the provided text description. The partition +layout is alternatively read from the 'mbr_parts' environment variable. +This can be used in scripts to help system image flashing tools to ensure +proper partition layout. + +The syntax of the text description of the partition list is similar to +the one used by the 'gpt' command. + +Supported partition parameters are: + +* name (currently ignored) +* start (partition start offset in bytes) +* size (in bytes or '-' to expand it to the whole free area) +* bootable (boolean flag) +* id (MBR partition type) + +If one wants to create more than 4 partitions, an 'Extended' primary +partition (with 0x05 ID) has to be explicitly provided as a one of the +first 4 entries. + +Here is an example how to create a 6 partitions (3 on the 'extended +volume'), some of the predefined sizes: + +:: + + => setenv mbr_parts 'name=boot,start=4M,size=128M,bootable,id=0x0e; + name=rootfs,size=3072M,id=0x83; + name=system-data,size=512M,id=0x83; + name=[ext],size=-,id=0x05; + name=user,size=-,id=0x83; + name=modules,size=100M,id=0x83; + name=ramdisk,size=8M,id=0x83' + => mbr write mmc 0 + +To check if the layout on the MMC #0 storage device matches the provided +text description one has to issue following command (assuming that +mbr_parts environment variable is set): + +:: + + => mbr verify mmc 0 + +The verify sub-command is especially useful in the system update scripts: + +:: + + => if mbr verify mmc 0; then + echo MBR layout needs to be updated + ... + fi + +The 'mbr write' command returns 0 on success write or 1 on failure. + +The 'mbr verify' returns 0 if the layout matches the one on the storage +device or 1 if not. + +Configuration +------------- + +To use the mbr command you must specify CONFIG_CMD_MBR=y. + +Return value +------------ + +The variable *$?* takes the following values + ++---+------------------------------+ +| 0 | mbr write was succesful | ++---+------------------------------+ +| 1 | mbr write failed | ++---+------------------------------+ +| 0 | mbr verify was succesful | ++---+------------------------------+ +| 1 | mbr verify was not succesful | ++---+------------------------------+ +|-1 | invalid arguments | ++---+------------------------------+ diff --git a/doc/usage/pstore.rst b/doc/usage/pstore.rst index 8c4e5274aa1..1c8374513aa 100644 --- a/doc/usage/pstore.rst +++ b/doc/usage/pstore.rst @@ -1,8 +1,17 @@ .. SPDX-License-Identifier: GPL-2.0+ -PStore command +pstore command ============== +Synopsis +-------- + +:: + + pstore set <addr> <len> [record-size] [console-size] [ftrace-size] [pmsg_size] [ecc-size] + pstore display [record-type] [nb] + pstore save <interface> <dev[:part]> <directory-path> + Design ------ |