diff options
author | Heinrich Schuchardt <heinrich.schuchardt@canonical.com> | 2022-06-19 14:59:22 +0300 |
---|---|---|
committer | Heinrich Schuchardt <heinrich.schuchardt@canonical.com> | 2022-06-19 16:53:09 +0300 |
commit | eaa268589e9cf81f37314f8efaebdb4dbb781647 (patch) | |
tree | f5126ffa4a0ae3cf15ec3239b212fd79de6be265 /doc | |
parent | a8a349d743065430b004ebfc112ae6c24168359b (diff) | |
download | u-boot-eaa268589e9cf81f37314f8efaebdb4dbb781647.tar.xz |
doc: man-page for the printenv command
Privide a man-page for the printenv command.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Diffstat (limited to 'doc')
-rw-r--r-- | doc/usage/cmd/printenv.rst | 90 | ||||
-rw-r--r-- | doc/usage/index.rst | 1 |
2 files changed, 91 insertions, 0 deletions
diff --git a/doc/usage/cmd/printenv.rst b/doc/usage/cmd/printenv.rst new file mode 100644 index 0000000000..9cb20f6ce6 --- /dev/null +++ b/doc/usage/cmd/printenv.rst @@ -0,0 +1,90 @@ +.. SPDX-License-Identifier: GPL-2.0+: + +printenv command +================ + +Synopsis +-------- + +:: + + printenv [-a] [name ...] + printenv -e [-guid guid][-n] [name] + +Description +----------- + +The printenv command is used to print environment or UEFI variables. + +\-a + Print environment variables starting with a period ('.'). + +\-e + Print UEFI variables. Without -e environment variables are printed. + +\-guid *guid* + Specify vendor GUID *guid*. If none is specified, all UEFI variables with + the specified name are printed irrespective of their vendor GUID. + +\-n + don't show hexadecimal dump of value + +name + Variable name. If no name is provided, all variables are printed. + Multiple environment variable names may be specified. + +Examples +-------- + +The following examples demonstrates the effect of the *-a* flag when displaying +environment variables: + +:: + + => setenv .foo bar + => printenv + arch=sandbox + baudrate=115200 + board=sandbox + ... + stdout=serial,vidconsole + + Environment size: 644/8188 bytes + => printenv -a + .foo=bar + arch=sandbox + baudrate=115200 + board=sandbox + ... + stdout=serial,vidconsole + + Environment size: 653/8188 bytes + => + +The next example shows the effect of the *-n* flag when displaying an UEFI +variable and how to specify a vendor GUID: + +:: + + => printenv -e -guid 8be4df61-93ca-11d2-aa0d-00e098032b8c PlatformLangCodes + PlatformLangCodes: + 8be4df61-93ca-11d2-aa0d-00e098032b8c (EFI_GLOBAL_VARIABLE_GUID) + BS|RT|RO, DataSize = 0x6 + 00000000: 65 6e 2d 55 53 00 en-US. + => printenv -e -n PlatformLangCodes + PlatformLangCodes: + 8be4df61-93ca-11d2-aa0d-00e098032b8c (EFI_GLOBAL_VARIABLE_GUID) + BS|RT|RO, DataSize = 0x6 + => + +Configuration +============= + +UEFI variables are only supported if CONFIG_CMD_NVEDIT_EFI=y. The value of UEFI +variables can only be displayed if CONFIG_HEXDUMP=y. + +Return value +------------ + +The return value $? is 1 (false) if a specified variable is not found. +Otherwise $? is set to 0 (true). diff --git a/doc/usage/index.rst b/doc/usage/index.rst index 1c03b9b33b..770418434a 100644 --- a/doc/usage/index.rst +++ b/doc/usage/index.rst @@ -49,6 +49,7 @@ Shell commands cmd/md cmd/mmc cmd/pinmux + cmd/printenv cmd/pstore cmd/qfw cmd/reset |