[U-Boot-Users] ' Configuring Flash on PPC405ep board'

nreddy at netenrich.com nreddy at netenrich.com
Fri Sep 23 13:37:32 CEST 2005

Hi Stefan,

Thanks for your suggestion.

I enabled 8MB flash on my board.
It started working now.
Still i need to check thoroughly.

I have taken reference driver from /board/walnut405 .

Thanks once again.


> Hi Nagi,
> On Friday 23 September 2005 12:09, nreddy at netenrich.com wrote:
>> I need to know how to configure 8MB Flash on PPC405ep board.
>> I already have 4MB flash on PPC405ep board working fine .
>> I am using u-boot as my bootloader.
> That's good. If not, your mail would be pretty wrong here in this list!
> ;-)
>> Can anybody tell me what are the registers to be configured at Processor
>> side(i am new to this register settings) or memory controller side.
> If you are lucky, you "only" have to change the EBC (external bus
> controller)
> setup for the corresponding CS (chip select). Please see e.g. below some
> lines from the bubinga (AMCC 405EP eval board) config file
> (include/configs/bubinga.h):
> /* Memory Bank 0 (Flash/SRAM) initialization
> */
> #define CFG_EBC_PB0AP           0x04006000
> #define CFG_EBC_PB0CR           0xFFF18000  /*
> BAS=0xFFF,BS=1MB,BU=R/W,BW=8bit
> */
> To change the size of this CS0 setup, you need to change the BAS field and
> the
> BS field. E.g. to something like this:
> #define CFG_EBC_PB0CR           0xFF8E8000  /*
> BAS=0xFF8,BS=8MB,BU=R/W,BW=8bit
> But I would suggest that you take a look at the 405EP user's manual to
> check
> yourself. It's not that complicated.
> Now you (hopefully) have the CS setup correctly, but you also have to
> configure/change your flash driver to support this new flash. Do you use
> the
> common CFI driver? Or a board specific version?
>> Please tell me the steps that i need to follow to write my own dirver(i
>> may take existing driver as reference).
> Best regards,
> Stefan

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