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author | Tom Rini <trini@konsulko.com> | 2022-07-27 06:59:55 -0400 |
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committer | Tom Rini <trini@konsulko.com> | 2022-07-27 06:59:55 -0400 |
commit | 7277c4bddceb6b8a59ba47b8b111ab070d86919f (patch) | |
tree | 0bd1db6551763d178d25e80a350be458150c9e8e /doc | |
parent | 81e712a91729950fbd8fb38a6f729cb9847b0adb (diff) | |
parent | dce4322c0e1940e11ef9ff086890b8c474707317 (diff) | |
download | u-boot-7277c4bddceb6b8a59ba47b8b111ab070d86919f.zip u-boot-7277c4bddceb6b8a59ba47b8b111ab070d86919f.tar.gz u-boot-7277c4bddceb6b8a59ba47b8b111ab070d86919f.tar.bz2 |
Merge tag 'dm-pull-26jul22' of https://gitlab.denx.de/u-boot/custodians/u-boot-dm.git
minor dm- and fdt-related fixes
start of test for fdt command
Diffstat (limited to 'doc')
-rw-r--r-- | doc/develop/logging.rst | 19 | ||||
-rw-r--r-- | doc/usage/cmd/fdt.rst | 69 | ||||
-rw-r--r-- | doc/usage/index.rst | 1 |
3 files changed, 77 insertions, 12 deletions
diff --git a/doc/develop/logging.rst b/doc/develop/logging.rst index 51095b0..704a6bf 100644 --- a/doc/develop/logging.rst +++ b/doc/develop/logging.rst @@ -66,26 +66,21 @@ Sometimes it is useful to turn on logging just in one file. You can use this #define LOG_DEBUG to enable building in of all logging statements in a single file. Put it at -the top of the file, before any #includes. - -To actually get U-Boot to output this you need to also set the default logging -level - e.g. set CONFIG_LOG_DEFAULT_LEVEL to 7 (:c:data:`LOGL_DEBUG`) or more. -Otherwise debug output is suppressed and will not be generated. +the top of the file, before any #includes and any message in the file will be +written, regardless of the value of CONFIG_LOG_DEFAULT_LEVEL. Using DEBUG ----------- U-Boot has traditionally used a #define called DEBUG to enable debugging on a -file-by-file basis. The debug() macro compiles to a printf() statement if -DEBUG is enabled, and an empty statement if not. +file-by-file basis but LOG_DEBUG are intended to replace it with the logging +facilities; DEBUG is activated when LOG_DEBUG is activated. With logging enabled, debug() statements are interpreted as logging output -with a level of LOGL_DEBUG and a category of LOGC_NONE. +with a level of LOGL_DEBUG and a category of LOG_CATEGORY. -The logging facilities are intended to replace DEBUG, but if DEBUG is defined -at the top of a file, then it takes precedence. This means that debug() -statements will result in output to the console and this output will not be -logged. +With logging disabled, the debug() macro compiles to a printf() statement +if DEBUG is enabled and to an empty statement if not. Logging statements ------------------ diff --git a/doc/usage/cmd/fdt.rst b/doc/usage/cmd/fdt.rst new file mode 100644 index 0000000..07fed73 --- /dev/null +++ b/doc/usage/cmd/fdt.rst @@ -0,0 +1,69 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +fdt command +=========== + +Synopis +------- + +:: + + fdt addr [-cq] [addr [len]] + +Description +----------- + +The fdt command provides access to flat device tree blobs in memory. It has +many subcommands, some of which are not documented here. + +Flags: + +-c + Select the control FDT (otherwise the working FDT is used). +-q + Don't display errors + +The control FDT is the one used by U-Boot itself to control various features, +including driver model. This should only be changed if you really know what you +are doing, since once U-Boot starts it maintains pointers into the FDT from the +various driver model data structures. + +The working FDT is the one passed to the Operating System when booting. This +can be freely modified, so far as U-Boot is concerned, since it does not affect +U-Boot's operation. + +fdt addr +~~~~~~~~ + +With no arguments, this shows the address of the current working or control +FDT. + +If the `addr` argument is provided, then this sets the address of the working or +control FDT to the provided address. + +If the `len` argument is provided, then the device tree is expanded to that +size. This can be used to make space for more nodes and properties. It is +assumed that there is enough space in memory for this expansion. + +Example +------- + +Get the control address and copy that FDT to free memory:: + + => fdt addr -c + Control fdt: 0aff9fd0 + => cp.b 0aff9fd0 10000 10000 + => md 10000 4 + 00010000: edfe0dd0 5b3d0000 78000000 7c270000 ......=[...x..'| + +The second word shows the size of the FDT. Now set the working FDT to that +address and expand it to 0xf000 in size:: + + => fdt addr 10000 f000 + => md 10000 4 + 00010000: edfe0dd0 00f00000 78000000 7c270000 ...........x..'| + +Return value +------------ + +The return value $? indicates whether the command succeeded. diff --git a/doc/usage/index.rst b/doc/usage/index.rst index 8b98629..16a3db5 100644 --- a/doc/usage/index.rst +++ b/doc/usage/index.rst @@ -43,6 +43,7 @@ Shell commands cmd/false cmd/fatinfo cmd/fatload + cmd/fdt cmd/for cmd/load cmd/loadm |