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45 lines
1.3 KiB
ReStructuredText
45 lines
1.3 KiB
ReStructuredText
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.. SPDX-License-Identifier: GPL-2.0-or-later:
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read and write commands
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=======================
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Synopsis
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--------
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::
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read <interface> <dev[:part|#partname]> <addr> <blk#> <cnt>
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write <interface> <dev[:part|#partname]> <addr> <blk#> <cnt>
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The read and write commands can be used for raw access to data in
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block devices (or partitions therein), i.e. without going through a
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file system.
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read
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----
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The block device is specified using the <interface> (e.g. "mmc") and
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<dev> parameters. If the block device has a partition table, one can
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optionally specify a partition number (using the :part syntax) or
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partition name (using the #partname syntax). The command then reads
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the <cnt> blocks of data starting at block number <blk#> of the given
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device/partition to the memory address <addr>.
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write
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-----
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The write command is completely equivalent to the read command, except
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of course that the transfer direction is reversed.
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Examples
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--------
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# Read 2 MiB from partition 3 of mmc device 2 to $loadaddr
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read mmc 2.3 $loadaddr 0 0x1000
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# Read 16 MiB from the partition named 'kernel' of mmc device 1 to $loadaddr
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read mmc 1#kernel $loadaddr 0 0x8000
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# Write to the third sector of the partition named 'bootdata' of mmc device 0
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write mmc 0#bootdata $loadaddr 2 1
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