topic Re: IVT table search by HAB in i.MX Processors

IVT table search by HAB

antonio_santagi — Mon, 16 Mar 2020 16:33:13 GMT

Hello,

I am using iMx8M Mini.

How does the HAB search for IVT table ?

Does it look for IVT on a fixed address or does it look for IVT in the selected memory to boot from sequentially ?

I found on another post that is supposed to look for it at offset 33 , but with no explanation on why that is or if it always to be at offset 33 . Is this offset valid both for eMMC and SD card ?

Does HAB support looking for files/tables on a FAT partition ?

Thank you

Re: IVT table search by HAB

joanxie — Sun, 22 Mar 2020 12:30:43 GMT

for detailed information about IVT, you can refer to the chapter 6.1.6.1 Image Vector Table and Boot Data

i.MX 8M Mini Applications Processor | Arm Cortex A53/M4 | 1080P display | NXP

Re: IVT table search by HAB

antonio_santagi — Thu, 26 Mar 2020 20:49:48 GMT

Ok, I see offset 33 Kbyte from start , but even if there is GPT on eMMC with block size 1Kbyte, that means ending a at the last block GPT Header entries. Is IVT compatible with GPT scheme then ?

If block size is 512 then 33 Kbyte is somewhere in the middle of first partition.

Also if MBR partition scheme is instead of GPT 33 Kbyte means somewhere in first partition.

Re: IVT table search by HAB

joanxie — Wed, 01 Apr 2020 06:40:28 GMT

I'm not sure if I understand your meaning correct or not, maybe you can refer to the Reference Manual of imx8MQ, GPT isn't part of IVT

Re: IVT table search by HAB

antonio_santagi — Wed, 01 Apr 2020 08:48:06 GMT

thank you.

Yes I saw the pictures. I was wondering why 33 Kbyte offset was chosen as it doesn't appear to fit on a Partition table, it is information hidden from partition table, isn't it ?

So, when I mount, for example, SD card that has already the layout ready for boot, I cannot see u-boot and other bootloaders that are placed after ivt table as they are not part of a filesystem of any partition listed in the partition table.

This is not a problem but just to understand why 33 Kbyte was chosen.

thank you

Re: IVT table search by HAB

joanxie — Sun, 05 Apr 2020 04:47:43 GMT

pls refer to the Table 1. Image layout in the 4.3 Preparing an SD/MMC card to boot and chapter 4.3.4 Copying a bootloader image of enclose file