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Diffstat (limited to 'Documentation/user/state.rst')
| -rw-r--r-- | Documentation/user/state.rst | 46 |
1 files changed, 44 insertions, 2 deletions
diff --git a/Documentation/user/state.rst b/Documentation/user/state.rst index 7d6c5770d5..d17f39befb 100644 --- a/Documentation/user/state.rst +++ b/Documentation/user/state.rst @@ -39,8 +39,8 @@ Backends (e.g. Supported Memory Types) Some non-volatile memory is need for storing a *state* variable set: -- all kinds of NOR flash memories -- all kinds of NAND flash memories +- Disk like devices: SD, (e)MMC, ATA +- all kinds of NAND and NOR flash memories (mtd) - MRAM - EEPROM - all kind of SRAMs (backup battery assumed) @@ -531,6 +531,48 @@ content, its backend-type and *state* variable layout. }; }; +SD/eMMC and ATA +############### + +The following devicetree node entry defines some kind of SD/eMMC memory and +a partition at a specific offset inside it to be used as the backend for the +*state* variable set. Note that currently there is no support for on-disk +partition tables. Instead, a ofpart partition description must be used. You +have to make sure that this partition does not conflict with any other partition +in the partition table. + +.. code-block:: text + + backend_state_sd: part@100000 { + label = "state"; + reg = <0x100000 0x20000>; + }; + +With this 'backend' definition its possible to define the *state* variable set +content, its backend-type and *state* variable layout. + +.. code-block:: text + + aliases { + state = &state_sd; + }; + + state_sd: state_memory { + #address-cells = <1>; + #size-cells = <1>; + compatible = "barebox,state"; + magic = <0xab67421f>; + backend-type = "raw"; + backend = <&backend_state_sd>; + backend-stridesize = <0x40>; + + variable { + reg = <0x0 0x1>; + type ="uint8"; + default = <0x1>; + }; + }; + SRAM #### |