The curious things about I.MX28 bootloader

[eunseokjung]

Hi, all.

I have some curious things about I.MX Bootloader.

I know that I.MX28 have secondary bootloader area which is used when primary boot fail.

My bootloader area is saved at 0x10000. And secondary is in 0x20000.

I did some experiment. I removed flash from 0x10000 to 0x30000.(I think here is bootloader area.)

After remove flash, its bootloader working properly. It is very strange. I think, it should fail. Because i remove bootloader area. But, it working well.

So my hypothesis is that I.MX28 have bootloader backup area. But i'm not sure. Do you have idea of this?

When i removed flash area form 0x00000 to 0x30000, the bootloader is not working.

Anyone who knows about this, please let me know.

Thank you.

Eunseok.

[igorpadykov · Accepted solution]

Hi Eunseok

address may depend on particular processor parameters, like

Search Area, Search Count and NAND page size.

Please check section 12.12.1.5 (Redundant Boot Support in ROM NAND driver)

about secondary boot details. Search Area, Search Count and NAND page size

define address of bootloader, it may be different. Take a look at Figure 12-7

(Expected NAND Layout with example search count = 4 and search stride = 1*64)

of the Reference Manual, where Boot Firmware 2 relates to the secondary boot image.

Best regards

igor

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