19 Sep
2003
19 Sep
'03
10:14 p.m.
Hello,
in message 3F6AD744.1030107@elsoft.ch you wrote:
So a multi stage boot process has to be implemented. After reset,
I agree.
hardware loads a tiny piece of code from the first two blocks of the NAND flash. This code has to do:
- minimial initialisation of CPU
- initialisation of SDRAM and NAND flash
- copy rest of boot code (U-Boot) from NAND to SDRAM while taking care of bad blocks
- jump to an appropriate place to give up control to rest of boot code
In my opinion, such a "primary boot loader" should be completely independend of U-Boot, i. e. you shouldbe able to use it to load any other boot loader as well, and the U-Boot code itself should only need minimal adjustment.
Best regards,
Wolfgang Denk
--
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd@denx.de
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