| .. SPDX-License-Identifier: GPL-2.0-or-later |
| |
| .. index:: |
| single: read (command) |
| |
| read command |
| ============ |
| |
| Synopsis |
| -------- |
| |
| :: |
| |
| read <interface> <dev[:part|#partname]> <addr> <blk#> <cnt> |
| |
| Description |
| ----------- |
| |
| The read command can be used for raw reading data from a block device |
| (or a partition therein), i.e. without going through a file system. |
| |
| 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>. |
| |
| Examples |
| -------- |
| |
| .. code-block:: bash |
| |
| # 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 |
| |
| Configuration |
| ------------- |
| |
| The read command is only available if CONFIG_CMD_READ=y. |
| |
| Return value |
| ------------ |
| |
| The command sets the return value $? to 0 (true) on success or to 1 (false) in |
| case of an error. |
