[U-Boot] Want to study U-Boot code

[Javier Martinez Canillas]

On Sat, Jan 26, 2013 at 2:07 PM, Woody Wu <narkewoody at gmail.com> wrote:
> 在 2013-1-26 AM5:27，"Robert P. J. Day" <rpjday at crashcourse.ca>写道：
>>
>> On Fri, 25 Jan 2013, Wolfgang Denk wrote:
>>
>> > Dear Woody Wu,
>> >
>> > In message <CAAsE_ue4VffAioQWzHPpyOZmzoFk9E5S7jj2+2BZuiK=
> C5yXtA at mail.gmail.com> you wrote:
>> > >
>> > > I want to firstly get a picture to basically understand how u-boot
>> > > work, especially on an ARM9 based board. I think not everyone who
>> > > want to understand u-boot has to read the full code.  Thank.
>> >
>> > This depends on your definition of "understanding".  On a highlevel,
>> > you might start with reaing and digesting the manual, eventually
>> > trying out how U-Boot works on some (real or emulated) board.
>>
>>   if i can jump in, a good way to start playing is to configure and
>> build for the "sandbox" architecture so you can run it on your x86
>> system.  for the benefit of a couple friends, i whipped together a
>> wiki page for that here:
>>
>> http://www.crashcourse.ca/wiki/index.php/U-Boot_sandbox
>>
>>   very simple but enough to get you started, and you can match up
>> running the commands with the underlying code.
>>
>> rday
>
> Sandbox looks amazing! Thanks share me with this info.  But i still
> wondering that if u-boot doesnt have any book or document explaining how it
> work and how it organized, how pepople can join its development?
>

Hello Woody,

I recommend you to start with the README file since it gives you a high level
overview of U-Boot and some very good specifics too.

Since you are asking about U-Boot source code organization specifically,
you can take a look at the "Directory Hierarchy" section of the README file.

But as others stated before, you should first narrow your search to an area that
interests you. I found that "scratching your own itch" is the best way to learn.

There is no documentation that can replace the source code itself, remember
that a good documentation shouldn't say how thinks are made (for that
you have the code)
but why things were made in a certain way and the design decisions behind that.

Finally, if you think that the documentation is not enough, feel free to send
patches to improve that :-)

As Confusios said "I heard and I forget. I see and I remember. I do
and I understand"

Hope it helps,
Javier