[U-Boot] there is no need for uboot to use linux's mtd driver!

[U-Boot] there is no need for uboot to use linux's mtd driver!

[liu.yaojin at zte.com.cn]

i am porting uboot to our board.and i am a fresh man to the uboot.
after several days on studying uboot.i found uboot's mtd drvier framework 
for nand is very foolish!

i think uboot should just have some api,such as 
read/write_page,oob,crc,but let them be null functions.
!!!because!!! the semiconductor company's engineers will provide the 
functions!!!.so when they port uboot to their cpu ,it will very 
easy.furthermore, using the null api is good to customer and kinds of 
engineers!~

we shouldn't spend so much time on bootloader.but the author seems to make 
our work harder!

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[U-Boot] there is no need for uboot to use linux's mtd driver!

[Wolfgang Denk]

Dear liu.yaojin at zte.com.cn,

In message <200906111737.n5BHblLO059758@mse1.zte.com.cn> you wrote:
>
> i am porting uboot to our board.and i am a fresh man to the uboot.
> after several days on studying uboot.i found uboot's mtd drvier framework 
> for nand is very foolish!

You are welcome to provide a patch that implements such a small and
efficient solution as you propose here - note that it should work on
all the processors and boards that are supported so far.

It's probably a good exercise for a newbie...  Happy hacking.


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 at denx.de
Until you walk a mile in another man's moccasins, you  can't  imagine
the smell.

[U-Boot] there is no need for uboot to use linux's mtd driver!

[Scott Wood]

On Tue, Jun 09, 2009 at 07:52:19PM +0800, liu.yaojin at zte.com.cn wrote:
> i am porting uboot to our board.and i am a fresh man to the uboot.
> after several days on studying uboot.i found uboot's mtd drvier framework 
> for nand is very foolish!

As Wolfgang pointed out, patches that actually improve things are welcome. 

Don't forget to account for the possibility that a board has more than
one type of NAND controller.

> i think uboot should just have some api,such as 
> read/write_page,oob,crc,but let them be null functions.
> !!!because!!! the semiconductor company's engineers will provide the 
> functions!!!.
 
Those functions would be almost identical for a many NAND controllers.

Note that you *can* provide your own read/write page, oob, crc, etc.
functions.  I agree that there should be a way for the generic functions
to not be compiled if they're not needed.

> we shouldn't spend so much time on bootloader.

That's precisely why Linux's code was reused, rather than spending time
writing something from scratch.

-Scott

[U-Boot] there is no need for uboot to use linux's mtd driver!

[Mike Frysinger]

On Tuesday 16 June 2009 14:33:00 Scott Wood wrote:
> I agree that there should be a way for the generic functions
> to not be compiled if they're not needed.

if gc-sections is used, then it isnt a problem ...
-mike
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[U-Boot] there is no need for uboot to use linux's mtd driver!

[Scott Wood]

Mike Frysinger wrote:
> On Tuesday 16 June 2009 14:33:00 Scott Wood wrote:
>> I agree that there should be a way for the generic functions
>> to not be compiled if they're not needed.
> 
> if gc-sections is used, then it isnt a problem ...

Not without some other changes -- there would still be references to the 
unused functions in the form of code that would set function pointers to 
them if those function pointers weren't already non-NULL.

-Scott