[U-Boot] U-boot running on DDR fails to detect the CFI compliant flash

[Jerry Van Baren <gerald.vanbaren@ge.com>]

Hi Prakash

Please quote properly and don't top post.  Your emails are very hard to 
understand.

prakash bedge wrote:
> Hi Albert and Stefan,
>  
> I have used the proper commands.
> i.e.
> mw.b 0xfc000000 0xf0
> mw.b 0xfc000055 0x98
> md.b 0xfc000010
> But still no positive results.
> Last time I forgot to tell here, that I have commneted the for(;;) loop 
> in "hang" function after flash_init result testing in lib_ppc/board.c 
> and then I am able to run the above commands on uboot prompt.
>  
> 1) You're writing 32-bit words to the chip. At most it should be 16-bit 
> words, possibly even 8-bits. Try mw.w and mw.b.
> Prakash - I tried both but no success.
> How to crosscheck the chipwidth? Can someone tell what is chipwidth and 
> portwidth?
> I believe I am using chipwidth - 16 and portwidth - 8. How to validate 
> this against chipwidth and portwidth?

Number one thing you *MUST* do is read the flash data sheets, especially 
the command interface.  Repeat until you understand.  Then try the QRY 
command sequence by hand in all the various possibilities (see thread 
links below).

* In your hardware, the "55" and "AA" addresses may be shifted by one or 
two bits:
<http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/31501/focus=31735>

* In your hardware, the command byte lane may be one byte wide, two 
bytes wide, or four bytes wide.  This changes the 55/AA addresses and 
which byte lane(s) are used for the command.
   * Do you have 1, 2, or 4 chips on your  board?
   * Is your memory bus 1, 2, or 4 bytes wide?

The thread links below will help explain.  Note that Robert is using the 
BDI, and thus using the BDI memory read/write commands.  You want to use 
u-boot's memory read/write commands instead.

Pay special attention to these posts:
<http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/31501/focus=31588>
<http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/31501/focus=31723>
<http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/31501/focus=31724>
<http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/31501/focus=31730>
<http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/31501/focus=31735>
<http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/31501/focus=31787>
<http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/31501/focus=31738>

Good luck,
gvb

[snip]