[U-Boot-Users] ARM cleanup - was: [GIT PULL] [ARM] Pleasepull fromgit://denx.de/git/u-boot-arm.git

Ulf Samuelsson ulf at atmel.com
Tue Sep 4 13:15:28 CEST 2007


>> This is definitely not the code which causes the board to reset.
>> It is the code start up the MCU.
>> Since the MCU is already executing from SDRAM at this stage, 
>> (loaded from dataflashboot.bin) there is no low level init to be done.
>> Any low level init at this stage will cause a crash.
>> 
> 
> Ulf
> Two questions before I revamp the patch
> 
> 1) Do you want your red led to show
> a) U-Boot code is running
> OR
> b) The MCU configuration code is running
> OR
> c) Something else
> so I can locate the LED code correctly.

I think you want the red LED to show that U-Boot is running.


> 
> 2) Will there be two types of build for the AT91RM9200 boards
> a) one that runs after dataflashboot.bin (and hence must not touch
> the MCU)
> b) one that runs direct from reset and must set up the MCU
>   or just one that runs after dataflashboot.bin
> so that I know whether we need to ifdef the code or just delete it (for
> AT91RM9200)

The AT91RM9200DK boots from a parallel flash and should boot either
directly from u-boot or from boot.bin
The AT91RM9200DK is obsolete, and it is definitely not recommended
to use this as an example.

The AT91RM9200EK can either boot from a parallel flash or from 
a dataflash, but can use the AT91RM9200DK board support
(with a few modifications)
For this, the user needs to choose in the header file if to 
boot from par or serial.

We must support both methods in the reset routine.

> 
> Regards
> 
> Peter
> 


Best Regards
Ulf Samuelsson






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