[rtems commit] JFFS2: Add device identifier for the flash device

Chris Johns chrisj at rtems.org
Tue Jun 17 09:08:30 UTC 2014


On 17/06/2014 6:51 pm, Sebastian Huber wrote:
> On 2014-06-16 21:56, Chris Johns wrote:
>> On 14/06/2014 2:00 am, Sebastian Huber wrote:
>>> Module:    rtems
>>> Branch:    master
>>> Commit:    73bf499ce7710ff8e75833042f88d1ff5b3e84fa
>>> Changeset:
>>> http://git.rtems.org/rtems/commit/?id=73bf499ce7710ff8e75833042f88d1ff5b3e84fa
>>>
>>>
>>> Author:    Sebastian Huber <sebastian.huber at embedded-brains.de>
>>> Date:      Tue Jun 10 10:56:55 2014 +0200
>>>
>>> JFFS2: Add device identifier for the flash device
>>>
>>> It is used in combination with the inode number to uniquely identify a
>>> file system node in the system.
>>>
>>> ---
>>>
>>>   cpukit/libfs/src/jffs2/include/rtems/jffs2.h |   11 ++++++++++-
>>>   cpukit/libfs/src/jffs2/src/fs-rtems.c        |    7 +++++--
>>>   2 files changed, 15 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/cpukit/libfs/src/jffs2/include/rtems/jffs2.h
>>> b/cpukit/libfs/src/jffs2/include/rtems/jffs2.h
>>> index e69fc20..7b2f4d5 100644
>>> --- a/cpukit/libfs/src/jffs2/include/rtems/jffs2.h
>>> +++ b/cpukit/libfs/src/jffs2/include/rtems/jffs2.h
>>> @@ -118,7 +118,8 @@ typedef struct rtems_jffs2_flash_control
>>> rtems_jffs2_flash_control;
>>>    *     .flash_size = FLASH_SIZE,
>>>    *     .read = flash_read,
>>>    *     .write = flash_write,
>>> - *     .erase = flash_erase
>>> + *     .erase = flash_erase,
>>> + *     .device_identifier = 0xc01dc0fe
>>
>> I cannot see anything that describes what this field is to contain. A
>> number is
>> a bit cryptic. Is this specific to a flash driver, all drivers, or
>> something
>> else ?
>>
>> I cannot find the flash driver used here so maybe a comment about this
>> and
>> where to find it would also help.
>
> The description is here:
>
> @@ -265,6 +266,14 @@ struct rtems_jffs2_flash_control {
>      * This operation is optional and the pointer may be @c NULL.
>      */
>     rtems_jffs2_flash_destroy destroy;
> +
> +  /**
> +   * @brief The device identifier of the flash device.
> +   *
> +   * It is used in combination with the inode number to uniquely
> identify a
> +   * file system node in the system.
> +   */
> +  dev_t device_identifier;
>   };
>
>   typedef struct rtems_jffs2_compressor_control
> rtems_jffs2_compressor_control;
>
> Due to the dev_t type it should be clear what it is.
>

Is there an example driver in the RTEMS source tree ?

Chris



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