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"Das U-Boot" Source Tree
1.. SPDX-License-Identifier: GPL-2.0+:
2
3.. index::
4 single: loads (command)
5
6loads command
7=============
8
9Synopsis
10--------
11
12::
13
14 loads [offset [baud]]
15
16Description
17-----------
18
19The loads command is used to transfer a file to the device via the serial line
20using the Motorola S-record file format.
21
22offset
23 offset added to the addresses in the S-record file
24
25baud
26 baud rate to use for download. This parameter is only available if
27 CONFIG_SYS_LOADS_BAUD_CHANGE=y
28
29Example
30-------
31
32As example file to be transferred we use a script printing 'hello s-record'.
33Here are the commands to create the S-record file:
34
35.. code-block:: bash
36
37 $ echo 'echo hello s-record' > script.txt
38 $ mkimage -T script -d script.txt script.scr
39 Image Name:
40 Created: Sun Jun 25 10:35:02 2023
41 Image Type: PowerPC Linux Script (gzip compressed)
42 Data Size: 28 Bytes = 0.03 KiB = 0.00 MiB
43 Load Address: 00000000
44 Entry Point: 00000000
45 Contents:
46 Image 0: 20 Bytes = 0.02 KiB = 0.00 MiB
47 $ srec_cat script.scr -binary -CRLF -Output script.srec
48 $ echo -e "S9030000FC\r" >> script.srec
49 $ cat script.srec
50 S0220000687474703A2F2F737265636F72642E736F75726365666F7267652E6E65742F1D
51 S1230000270519566D773EB6649815E30000001700000000000000003DE3D97005070601E2
52 S12300200000000000000000000000000000000000000000000000000000000000000000BC
53 S11A00400000000F0000000068656C6C6F20732D7265636F72640A39
54 S5030003F9
55 S9030000FC
56 $
57
58The load address in the first S1 record is 0x0000.
59
60The terminal emulation program picocom is invoked with *cat* as the send
61command to transfer the file.
62
63.. code-block::
64
65 picocom --send-cmd 'cat' --baud 115200 /dev/ttyUSB0
66
67After entering the *loads* command the key sequence <CTRL-A><CTRL-S> is used to
68let picocom prompt for the file name. Picocom invokes the program *cat* for the
69file transfer. The loaded script is executed using the *source* command.
70
71.. code-block::
72
73 => loads $scriptaddr
74 ## Ready for S-Record download ...
75
76 *** file: script.srec
77 $ cat script.srec
78
79 *** exit status: 0 ***
80
81 ## First Load Addr = 0x4FC00000
82 ## Last Load Addr = 0x4FC0005B
83 ## Total Size = 0x0000005C = 92 Bytes
84 ## Start Addr = 0x00000000
85 => source $scriptaddr
86 ## Executing script at 4fc00000
87 hello s-record
88 =>
89
90Configuration
91-------------
92
93The command is only available if CONFIG_CMD_LOADS=y. The parameter to set the
94baud rate is only available if CONFIG_SYS_LOADS_BAUD_CHANGE=y
95
96Return value
97------------
98
99The return value $? is 0 (true) on success, 1 (false) otherwise.