[U-Boot] framework for serial flash
Hello
We have a special "Serial flash controller" which was put into the standard flash framework of uboot (common/cmd_flash.c). Commands like 'cp', 'erase' could be used for operation over serial flash.
Now we have to use parallel flash (CFI), hence it is required to handle "Serial flash controller" in another manner as both are exporting 'write_buff' leading to a conflict.
Since we felt "Serial flash controller" resembles SPI flash framework, and hence decided to move it there. Problem is that this "Serial flash controller" is also not fitting in SPI framework because of its nature.
How to handle such situations, is there any other framework or we need to introduce our own commands? We are using "u-boot-2009.08".
Thanks Ashish
Dear ashish priyadarshi,
In message fb24d2790911102234x4d210e10mdd9d551541120dc0@mail.gmail.com you wrote:
We have a special "Serial flash controller" which was put into the standard flash framework of uboot (common/cmd_flash.c). Commands like 'cp', 'erase' could be used for operation over serial flash.
What do you mean by "Serial flash controller"? Some storage device similar to NAND or SPI Flash? This would not fit, then.
Since we felt "Serial flash controller" resembles SPI flash framework, and hence decided to move it there. Problem is that this "Serial flash controller" is also not fitting in SPI framework because of its nature.
So you already learned that your serial flash is not a type of memory, but a storage device. You cannot use the memory interface as used for NOR flash for it.
How to handle such situations, is there any other framework or we need to introduce our own commands? We are using "u-boot-2009.08".
That's difficult to impossible to answer - you don't provide any information what exact sort of device you have or why it would (not) fit into the SPI flash code.
Best regards,
Wolfgang Denk
Hello Wolfgang
Thanks for your reply.
The device composes of a Serial NOR flash (STmicro M25P64) and Serial Memory
Controller Interface (SMI). All operations such as Read-ID, read-data, write-data, and erase can be controlled by SMI. Like for Read-ID, first command is written into the TX register of SMI and then 3 bytes of flash-ID can be read back from Rx regsiter of SMI.
SMI differs from a normal SPI controller in this way that it manages a lot of things on its own. For example to read FLASH id we need to tell SMI beforehand how many bytes it has to read in response to this command. The SPI Flash interface however splits this in two seperate xfer calls where command is sent first and then response is read. regards Ashish
On Thu, Nov 12, 2009 at 3:02 AM, Wolfgang Denk wd@denx.de wrote:
Dear ashish priyadarshi,
In message fb24d2790911102234x4d210e10mdd9d551541120dc0@mail.gmail.com you wrote:
We have a special "Serial flash controller" which was put into the
standard
flash framework of uboot (common/cmd_flash.c). Commands like 'cp', 'erase'
could
be used for operation over serial flash.
What do you mean by "Serial flash controller"? Some storage device similar to NAND or SPI Flash? This would not fit, then.
Since we felt "Serial flash controller" resembles SPI flash framework,
and
hence decided to move it there. Problem is that this "Serial flash controller"
is
also not fitting in SPI framework because of its nature.
So you already learned that your serial flash is not a type of memory, but a storage device. You cannot use the memory interface as used for NOR flash for it.
How to handle such situations, is there any other framework or we need to introduce our own commands? We are using "u-boot-2009.08".
That's difficult to impossible to answer - you don't provide any information what exact sort of device you have or why it would (not) fit into the SPI flash code.
Best regards,
Wolfgang Denk
-- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de "I've seen it. It's rubbish." - Marvin the Paranoid Android
participants (2)
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ashish priyadarshi -
Wolfgang Denk