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uboot basics ?

U-Boot-Users Ram 2 participants 2 messages Aug 31, 2005

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Ram

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#0 lore raw

Hi,
I am going through the uboot drivers code for smc91111 ethernet controller in uboot.

My Objective is to know how boot loader configures the ethernet controller.

This is for the first time i am going thru a boot loader code.

I have some doubts:

How does a boot loader know which device is connected. say i have connected the smc 91111 ethernet
controller - how does it know it is smc91111 controller.

I think as soon as it detects the smc91111 controller is connected. it must configure that - i think the
code in drivers/smc91111.c must be executed.

What will happen if there are 2 ethernet controllers in the board. how u-boot responds to this.

However, i am not following the code given in smc91111.c i really dont know what it is doing ?.

i have the data sheets with me and going thru it. i must admit i am totally confused.

Does anybody know what constitues configuring a ethernet controller and what the code does ?.

i would request you to kindly let me the flow in u-boot. from startup to configuring ind. devices.

Any description is available in this matter will be very useful.

Any pointers in this matter is highly appreciated.

Thanks,

Regards,
Ram
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#1 lore raw
Quoted 2 lines · In message <[email protected]> you wrote:

How does a boot loader know which device is connected. say i have connected>

U-Boot is stupid. It doesn't "know" anything. It just does what you tell it.

Quoted 2 lines

the smc 91111 ethernet
controller - how does it know it is smc91111 controller.

It doesn't know. It juist runs the code you configure into it.

Quoted 1 line

I think as soon as it detects the smc91111 controller is connected. it must>

It doesn;t detect it. It just runs the init code if you configure it.

Quoted 2 lines

What will happen if there are 2 ethernet controllers in the board. how u-boot responds to this.

If just does what you configure...

Quoted 2 lines

Does anybody know what constitues configuring a ethernet controller and wha> t the code does ?.

I'd say such a question is off topic here. You are supposed to have a deep understanding of the hardware and driver code when digging into boot loader code.

Quoted 2 lines

i would request you to kindly let me the flow in u-boot. from startup to configuring ind. devices.

Just start at the reset entry point and follow the code. Ther eis no easy way to understand it all.

Quoted 1 line

Any description is available in this matter will be very useful.

Read the README and the manual.

Best regards,

Wolfgang Denk

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