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| author | Simon Glass <sjg@chromium.org> | 2021-07-24 18:03:37 +0300 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2021-08-02 20:32:14 +0300 |
| commit | 5f4b356121fdb520e4c9bb4fe3483c1a5f93439c (patch) | |
| tree | 24f72a6bf24307ee96ecdc6ef0d5e6e3eb93ade5 /doc | |
| parent | 7a4ff7c41bab8b43767eacc0b30ca1573ab6acb1 (diff) | |
| download | u-boot-5f4b356121fdb520e4c9bb4fe3483c1a5f93439c.tar.xz | |
doc: Add a note about number representation
Mention the default base of U-Boot in the command-line section. Add
examples for decimal and octal.
Signed-off-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/usage/cmdline.rst | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/doc/usage/cmdline.rst b/doc/usage/cmdline.rst index b3dbdb8b23..2d5127c955 100644 --- a/doc/usage/cmdline.rst +++ b/doc/usage/cmdline.rst @@ -54,3 +54,34 @@ General rules calling run with a list of variables as arguments), any failing command will cause "run" to terminate, i. e. the remaining variables are not executed. + +Representing numbers +-------------------- + +Most U-Boot commands use hexadecimal (hex) as the default base, for convenient +use of addresses, for example:: + + => md 1000 6 + 00001000: 2c786f62 00697073 03000000 0c000000 box,spi......... + 00001010: 67020000 00000000 ...g.... + +There is no need to add a `0x` prefix to the arguments and the output is shown +in hex also, without any prefixes. This helps to avoid clutter. + +Some commands use decimal where it is more natural:: + + => i2c dev 0 + Setting bus to 0 + => i2c speed + Current bus speed=400000 + => i2c speed 100000 + Setting bus speed to 100000 Hz + +In some cases the default is decimal but it is possible to use octal if that is +useful:: + + pmic dev pmic@41 + dev: 1 @ pmic@41 + => pmic write 2 0177 + => pmic read 2 + 0x02: 0x00007f |