u-boot/doc/usage/cmd/loads.rst
Heinrich Schuchardt 117bcc2683 doc: loads man-page
Provide a man-page for the loads command.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
2023-07-01 17:00:52 +02:00

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.. SPDX-License-Identifier: GPL-2.0+:
loads command
=============
Synopsis
--------
::
loads [offset [baud]]
Description
-----------
The loads command is used to transfer a file to the device via the serial line
using the Motorola S-record file format.
offset
offset added to the addresses in the S-record file
baud
baud rate to use for download. This parameter is only available if
CONFIG_SYS_LOADS_BAUD_CHANGE=y
Example
-------
As example file to be transferred we use a script printing 'hello s-record'.
Here are the commands to create the S-record file:
.. code-block:: bash
$ echo 'echo hello s-record' > script.txt
$ mkimage -T script -d script.txt script.scr
Image Name:
Created: Sun Jun 25 10:35:02 2023
Image Type: PowerPC Linux Script (gzip compressed)
Data Size: 28 Bytes = 0.03 KiB = 0.00 MiB
Load Address: 00000000
Entry Point: 00000000
Contents:
Image 0: 20 Bytes = 0.02 KiB = 0.00 MiB
$ srec_cat script.scr -binary -CRLF -Output script.srec
$ echo -e "S9030000FC\r" >> script.srec
$ cat script.srec
S0220000687474703A2F2F737265636F72642E736F75726365666F7267652E6E65742F1D
S1230000270519566D773EB6649815E30000001700000000000000003DE3D97005070601E2
S12300200000000000000000000000000000000000000000000000000000000000000000BC
S11A00400000000F0000000068656C6C6F20732D7265636F72640A39
S5030003F9
S9030000FC
$
The load address in the first S1 record is 0x0000.
The terminal emulation program picocom is invoked with *cat* as the send
command to transfer the file.
.. code-block::
picocom --send-cmd 'cat' --baud 115200 /dev/ttyUSB0
After entering the *loads* command the key sequence <CTRL-A><CTRL-S> is used to
let picocom prompt for the file name. Picocom invokes the program *cat* for the
file transfer. The loaded script is executed using the *source* command.
.. code-block::
=> loads $scriptaddr
## Ready for S-Record download ...
*** file: script.srec
$ cat script.srec
*** exit status: 0 ***
## First Load Addr = 0x4FC00000
## Last Load Addr = 0x4FC0005B
## Total Size = 0x0000005C = 92 Bytes
## Start Addr = 0x00000000
=> source $scriptaddr
## Executing script at 4fc00000
hello s-record
=>
Configuration
-------------
The command is only available if CONFIG_CMD_LOADS=y. The parameter to set the
baud rate is only available if CONFIG_SYS_LOADS_BAUD_CHANGE=y
Return value
------------
The return value $? is 0 (true) on success, 1 (false) otherwise.