Hi Arne,

On 14/05/2014 06:07, Arne Rovet wrote:

MAX_HW_CFG_SIZE_V2 is defined as 121 in tools/imximage.h, but I think the processor reference manual implies it can be larger (i.MX 6Dual/6Quad Applications Processor Reference Manual, Rev. 1, 04/2013).

In the section labelled "8.6.2 Device Configuration Data (DCD)" it says the DCD can be a maximum of 1768 bytes: "The maximum size of the DCD limited to 1768 bytes."

It is the same for MX53 - header V2 is valid for i.MX6 and also for i.MX53.

Have I misunderstood the link between the DCD size and MAX_HW_CFG_SIZE_V2? If so, where did the value of 121 for MAX_HW_CFG_SIZE_V2 come from?

I cannot answer this question. But even if the DCD can be longer, there is an initial load region size that is differnet (table 7-26 on i.MX53 manual, table 8-26 on i.MX6Q manual). For example, on SD the i-MX53 loads up 2KB, the i.MX6Q 4KB. The whole header must fit in the initial load region.

The main question is also if a large DCD table is needed. The DCD is supposed in U-Boot to set up the minimal requirement to let the processor to copy the u-boot image into RAM - the rest can be done in U-Boot code after the boot ROM has completed its job.

Best regards, Stefano Babic