Re: [U-Boot-Users] A question about initialization of SDRAM

In message Tx948882797899.26592@send2.inner-21cn.com you wrote:

I am trying to use ELDK to make a u-boot on the board with MPC852T.

"the board with MPC852T"? There is many such boards, most of them differnt.

There is declaration of rtx in cpu/mpc8xx/fec.c:

...

static RTXBD *rtx = NULL;

...

I think that "rtx" should be NULL at the first time fec_init() is entered,so the rtx will be given the value.
but after the ELDK make the u-boot, "rtx" isn't NULL at the first time fec_init() is entered, it is 0xffffffff.

What makes you think so? The code is running perfectly fine on many boards. Which specific problem do you see?

Before the word "memctl->memc_mbmr  = 0xD0924114" in the function initdram, rtx is NULL(0x0),but after that it
is 0xffffffff. Part of the fuction initdram is below:

Looks as if there was a bug in the SDRAM init sequence for your board.

I wonder what happens in "memctl->memc_mbmr = 0xD0924114;",would you please explain it to me ? Thanks!

Please see the processor's User's Manual; read the memory controller section.

Best regards,

Wolfgang Denk