cmd: xxd: add new command

Add xxd command to print file content as hexdump to standard out

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Roger Knecht <rknecht@pm.me>

1 files changed, 50 insertions, 0 deletions

diff --git a/doc/usage/cmd/xxd.rst b/doc/usage/cmd/xxd.rst
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+.. SPDX-License-Identifier: GPL-2.0+:
+
+xxd command
+===============
+
+Synopsis
+--------
+
+::
+
+    xxd <interface> <dev[:part]> <file>
+
+Description
+-----------
+
+The xxd command prints the file content as hexdump to standard out.
+
+interface
+    interface for accessing the block device (mmc, sata, scsi, usb, ....)
+
+dev
+    device number
+
+part
+    partition number, defaults to 1
+
+file
+    path to file
+
+Example
+-------
+
+Here is the output for a example text file:
+
+::
+
+    => xxd mmc 0:1 hello
+    00000000: 68 65 6c 6c 6f 20 77 6f 72 6c 64 0a 00 01 02 03  hello world.....
+    00000010: 04 05                                            ..
+    =>
+
+Configuration
+-------------
+
+The xxd command is only available if CONFIG_CMD_XXD=y.
+
+Return value
+------------
+
+The return value $? is set to 0 (true) if the file is readable, otherwise it returns a non-zero error code.