topic Re: Vybrid HAB Setup in Vybrid Processors

Re: Vybrid HAB Setup

julienmaudet — Mon, 24 Jul 2017 15:06:18 GMT

Ryan,

It is written in hab.c of u-boot for imx6 that "If the MMU is enabled, we have to notify the ROM code, or it won't flush the caches when needed. This is done, by setting the "pu_irom_mmu_enabled" word to 1. This is critical for authenticate_image()".
Was it necessary to authenticate the uImage on the Vybrid?

Thanks,

Julien

Re: Vybrid HAB Setup

Yuri — Mon, 31 Jul 2017 06:11:32 GMT

Hello,

It depends on application - if signed kernel should be used, then

authenticate_image() is necessary to check the kernel.

Have a great day,
Yuri

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Re: Vybrid HAB Setup

julienmaudet — Mon, 31 Jul 2017 07:24:29 GMT

Hello Yuri,

I was able to authenticate my signed kernel by using authenticate_image(), but only if I disable the MMU caching on the OCRAM.

My problem is that I would like to keep the MMU caching enabled. For that, it seems that I have to notify the boot ROM by setting the "pu_irom_mmu_enabled" word to 1. Do you have the address of this word for vybrid processor MVF50NS151CMK40 ?

Thanks,

Julien

Re: Vybrid HAB Setup

Yuri — Tue, 01 Aug 2017 09:56:41 GMT

Hello,

BT_MMU_DISABLE is BOOT_CFG3[6].

Regards,

Yuri.

Re: Vybrid HAB Setup

degle — Tue, 01 Aug 2017 12:30:27 GMT

Hello Julien,

I have been trying to a Linux kernel authenticated on a Vybrid processor as well and I have not had success yet. I have not tried disabling the MMU on OCRAM yet.

But I was wondering if you could tell me what modifications you made to the hab.c and hab.h code to get it to successfully authenticate the Linux image? And any other Vybrid configuration changes other than the OCRAM MMU?

Re: Vybrid HAB Setup

julienmaudet — Tue, 01 Aug 2017 13:05:34 GMT

Hello,

In hab.h, you will have to change HAB_RVT_BASE to 0x54 and also set :

HAB_RVT_ENTRY = HAB_RVT_BASE + 0x4

HAB_RVT_EXIT = HAB_RVT_BASE + 0x8

HAB_RVT_AUTHENTICATE_IMAGE = HAB_RVT_BASE + 0x10

HAB_RVT_REPORT_EVENT = HAB_RVT_BASE + 0x20

HAB_RVT_REPORT_STATUS = HAB_RVT_BASE + 0x24

You will also need to enable SNVS clock before any call to HAB API.

Julien