[U-Boot-Users] .../board/fads/flash.c confuses me - give me a hint

[Wolfgang Denk]

In message <41E590B4.6080700 at orkun.us> you wrote:
>
> I'll jump in. Initially, each board had its own flash.c. cfi_flash.c 
> came later and some board maintainers switched to it and others did not 
> update their implementation for some reason. If your board can be 

One of the reasons is code size and efficiency. For example:

-> MAKEALL OXC
Configuring for OXC board...
   text    data     bss     dec     hex filename
 126100    8040   35988  170128   29890 u-boot
-> ppc_8xx-size board/oxc/flash.o
   text    data     bss     dec     hex filename
   2256      84       0    2340     924 board/oxc/flash.o
-> MAKEALL uc100
Configuring for uc100 board...
   text    data     bss     dec     hex filename
 164164   10260  218452  392876   5feac u-boot
-> ppc_8xx-size drivers/cfi_flash.o
   text    data     bss     dec     hex filename
   6040     116       0    6156    180c drivers/cfi_flash.o

As you can see, the CFI flash driver is nearly 3 times as  big  as  a
customized flash driver.

In some cases there is ample space and this doesn't matter, in  other
cases things are different.

> supported by cfi_flash.c and works well, it is probably not a good idea 
> to develop a custom flash driver.

I disagree if you give this as general advice. You have to  know  the
requirements  of  the project, and understand what you're doing. Only
then you can give intelligent advice.


Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
The project was large enough and management communication poor enough
to prompt many members of the team to see themselves  as  contestants
making  brownie  points,  rather  than as builders making programming
products. Each suboptimized  his  piece  to  meet  his  targets;  few
stopped to think about the total effect on the customer.
                              - Fred Brooks, "The Mythical Man Month"