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i.mx6 boot

Question asked by jiefeng zhang on Jun 8, 2014
Latest reply on Jun 11, 2014 by jiefeng zhang

chip : i.mx6q

 

I think after reading the datasheetchip startup process is as follows:

 

1、When the chip start-up(boot from SD card) , Chip will copy the SD card code from 0x400 to the internal RAM.(copy length is 4K)

 

2、Internal ROM code will check IVT and DCD , and then perform DCD to initialize the DDR.

 

3、Internal ROM code will copy boot_data->length specifies the length of the data to boot_data specified address , and then jump to entry the specified address.

 

question :

1、The above view is correct?


2、How do Internal ROM code find the DCD?


In my code ,the address offset is 0x27800000(As long as the memory address range , For example : 0x10000000 ) :

boot_data->start       = 0x27800000

DCD(Absolute address)     = 0x2780042C

entry                  = 0x278006E0


I try change the DCD(Absolute address) , but code is not working .

The DDR initialization after finding DCD , Why DCD(Absolute address) in the memory address ? How do Internal ROM code find the DCD? Internal ROM should not find DCD according to the address in memory.


Forgive my English is not good , thanks.


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