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author | Rasmus Villemoes <rasmus.villemoes@prevas.dk> | 2023-03-02 09:12:23 +0100 |
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committer | Tom Rini <trini@konsulko.com> | 2023-03-17 15:44:01 -0400 |
commit | d4048c7ac75524ec7ea4aad3e87d6ebac41e7ba9 (patch) | |
tree | 691b3e0413bd976894010359bfeb0a5d44091910 | |
parent | 8311ac5fe0831ae26ffb68fab6b927b18d7036d2 (diff) | |
download | u-boot-d4048c7ac75524ec7ea4aad3e87d6ebac41e7ba9.zip u-boot-d4048c7ac75524ec7ea4aad3e87d6ebac41e7ba9.tar.gz u-boot-d4048c7ac75524ec7ea4aad3e87d6ebac41e7ba9.tar.bz2 |
doc: document read/write commands
The read and write commands are, deliberately, implemented in the same
file, so that they stay feature-compatible (e.g. if someone implements
support for "read the full partition, however large that is", that
same syntax should also work for write). In order to ensure the
documentation for both are similarly kept in sync, and to avoid
duplication, document them both in read.rst, and add a stub write.rst
referring to read.rst.
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Simon Glass <sjg@chromium.org>
-rw-r--r-- | doc/usage/cmd/read.rst | 44 | ||||
-rw-r--r-- | doc/usage/cmd/write.rst | 6 | ||||
-rw-r--r-- | doc/usage/index.rst | 2 |
3 files changed, 52 insertions, 0 deletions
diff --git a/doc/usage/cmd/read.rst b/doc/usage/cmd/read.rst new file mode 100644 index 0000000..8408467 --- /dev/null +++ b/doc/usage/cmd/read.rst @@ -0,0 +1,44 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later: + +read and write commands +======================= + +Synopsis +-------- + +:: + + read <interface> <dev[:part|#partname]> <addr> <blk#> <cnt> + write <interface> <dev[:part|#partname]> <addr> <blk#> <cnt> + +The read and write commands can be used for raw access to data in +block devices (or partitions therein), i.e. without going through a +file system. + +read +---- + +The block device is specified using the <interface> (e.g. "mmc") and +<dev> parameters. If the block device has a partition table, one can +optionally specify a partition number (using the :part syntax) or +partition name (using the #partname syntax). The command then reads +the <cnt> blocks of data starting at block number <blk#> of the given +device/partition to the memory address <addr>. + +write +----- + +The write command is completely equivalent to the read command, except +of course that the transfer direction is reversed. + +Examples +-------- + + # Read 2 MiB from partition 3 of mmc device 2 to $loadaddr + read mmc 2.3 $loadaddr 0 0x1000 + + # Read 16 MiB from the partition named 'kernel' of mmc device 1 to $loadaddr + read mmc 1#kernel $loadaddr 0 0x8000 + + # Write to the third sector of the partition named 'bootdata' of mmc device 0 + write mmc 0#bootdata $loadaddr 2 1 diff --git a/doc/usage/cmd/write.rst b/doc/usage/cmd/write.rst new file mode 100644 index 0000000..06ad77e --- /dev/null +++ b/doc/usage/cmd/write.rst @@ -0,0 +1,6 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later: + +write command +============= + +See :doc:`cmd/read`. diff --git a/doc/usage/index.rst b/doc/usage/index.rst index ebf5eea..d01d38c 100644 --- a/doc/usage/index.rst +++ b/doc/usage/index.rst @@ -72,6 +72,7 @@ Shell commands cmd/printenv cmd/pstore cmd/qfw + cmd/read cmd/reset cmd/rng cmd/sbi @@ -92,6 +93,7 @@ Shell commands cmd/ut cmd/wdt cmd/wget + cmd/write cmd/xxd Booting OS |