[U-Boot] Some question about uboot

[Wolfgang Denk]

Dear loody,

In message <3a665c760902240521y768bead8x9bebc4a30ac04f2e at mail.gmail.com> you wrote:
>
> If I only need uboot to do cpu basic setting with USB ehci and file
> system support, does it still need 128k at least?

File system support is big (which file system(s) are we talking
about?), and USB support is BIG.

You will most probably need more than 128 k.

> Would you please tell me how to add a new cpu and platform in uBoot?
> I know the first step I have to do is adding my cpu and platform
> folder. But I have no idea how to add setting in Makefile.
> why sometimes we use "@$(MKCONFIG) $(@:_config=)" ,sometimes we use
> "@$(MKCONFIG) -a" and sometimes we have to " @mkdir -p $(obj)include"
> before calling mkconfig?

Well, read the source code. It's the best documentation we have - it
is exact, and detailed.

> I try to modify platform.h located at include/configs to remove
> unnecessary driver.

This is not the way to configure U-Boot. 

> But I have no idea which one I can remove such that the unnecessary
> driver will no compile my uboot.

As a first step you need an in depth understanding of your  hardware.
This will tell you exactly which drivers are needed for the operation
of your system as you want to use it.

Note that nobody else can tell you that - we don't know your hardware,
and we don;t know your requirements.

> for example, I remove "CONFIG_DRIVER_CS8900" in smdk2410.h, and the
> error message while linking is "net/libnet.a(net.o): In function
> `NetSendPacket':
> /media/u-boot_20090224_snapshot/net/net.c:654: undefined reference to
> `eth_send'"

You are taking the wrong approach. If you rip out the network  driver
without  disabling  network  support  you  will obviously get errors.
Hoever, if you just disable network support, then the network  driver
may go out of way automagically.


Best regards,

Wolfgang Denk

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DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
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