Re: [U-Boot] Hangs at relocation on 460EX Target

Hi, Stefan

Stefan Roese wrote:

Felix,

On Thursday 23 October 2008, Felix Radensky wrote:

...

I had the same problem with u-boot-1.3.4 on custom 460EX board with registered SODIMM. The SPD code in 4xx_spd_ddr2.c (program_copt1()) checks two SPD fields to decide whether DIMM is registered: DDRII DIMM type (offset 20) and SDRAM module attributes (offset 21).

In my case, the values in these fields do not match what code is looking for. See http://www.micron.com/products/spddetail.aspx?part=MT9HTF6472RHY-667F1 I had to modify the following peice in program_copt1() to make it work:

        if (dimm_num == 0) {
            if (dimm_populated[dimm_num] == SDRAM_DDR1) /* DDR1 type */
                mcopt1 |= SDRAM_MCOPT1_DDR1_TYPE;
            if (dimm_populated[dimm_num] == SDRAM_DDR2) /* DDR2 type */
                mcopt1 |= SDRAM_MCOPT1_DDR2_TYPE;
            if (registered == 1) { /* DDR2 always buffered */
                /* TODO: what about above  comments ? */
                mcopt1 |= SDRAM_MCOPT1_RDEN;
                buf0 = TRUE;
            } else {
                /* TODO: the mask 0x02 doesn't match Samsung def for

byte 21. */

So it seems already to be know that here is a problem.

...

                if ((attribute & 0x02) == 0x00) {
                    /* buffered not supported */
                    buf0 = FALSE;
                } else {
                    mcopt1 |= SDRAM_MCOPT1_RDEN;
                    buf0 = TRUE;
                }
            }
        }

I've changed

if ((attribute & 0x02) == 0x00)

to be

if (((attribute & 0x02) == 0x00) && (attribute != 0x04))

Why did you change it this way? Which DDR2 module are you using? And what's the value of SPD register 21?

My change causes the code to go into else branch and set SDRAM_MCOPT1_RDEN (registered) bit. I'm using Micron 512M registered SODIMM. The value of SPD register 21 is 0x4. The full SPD spec is here: http://www.micron.com/products/spddetail.aspx?part=MT9HTF6472RHY-667F1

Felix.