Hi all, we have developed a board very similar to MPC8306SOM board. We have 
some problems to run u-boot on. Briefly, the board has the same main components 
of the som board (RAM, NAND chip and a MPC8306 microprocessor) so we tried to 
use the same u-boot-nand.bin image for the boot. Something happens: the board 
starts, prints the message "NAND boot...transfering control" and nothing else 
happens. The first code is executed in NAND until nand_boot function (defined 
in the file nand_spl/nand_boot_fsl_elbc.c) is called: this copies in RAM the 
u-boot image and jumps at the address 0x01000000. To make we sure that RAM is 
working ok we have modified the u-boot-nand.bin with istructions that reset the 
processor and all works ok. Surely the jump at 0x01000000 happens and u-boot 
code starts to be executed but surely for some unknown reasons something goes 
wrong. Follow the u-boot code is very difficult also because is not clear to us 
how the "parts" of the boot loader are linked toghet
 er. Now some questions:

1- Looking at the dump of u-boot-nand.bin we saw that there are two "parts" of 
code very similar: one starts at offset 0x0 and the other at offset 0x20000. 
Both parts begin with a reset configuration word followed by the u-boot magic 
number, string version etc... Which is the purpose of this two parts?This could 
be useful to better understand the boot process. For now we know only that the 
processor reads the configuration word in NAND at offset 0x0 and starts to 
execute istructions from offset 0x100 in NAND. The second "part" (that starts 
at offset 0x20000) is then copied in RAM and the code that is executed is at 
location 0x01000120 in RAM.

2 - In the function nand_boot defined in nand_spl/nand_boot_fsl_elbc.c the last 
istruction is the call to the function pointed by the function pointer uboot 
(its value is 0x01000120). Where can i find the code executed here? Which is 
the relative source file? Looking at that source file maybe i can find where 
the boot could stop.  

Thank you all very much!

Best regards,

Mirko

--
Mirko Banchi

e-mail:    mk.ban...@gmail.com
id-jabber: mk.ban...@jabber.org

PGP key fingerprint:

308F BFB1 4E67 2522 C88E 
DC69 7631 52ED 32A5 6456



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