i.MX ProcessorsのトピックGetting HAB to auth signed kernel on a MX8Mini

Getting HAB to auth signed kernel on a MX8Mini

adam_m — Fri, 11 Dec 2020 17:38:03 GMT

I am working on getting uboot to load a secure kernel on a Boundary Devices Nitrogen8MM. I have already worked through the instructions at https://boundarydevices.com/high-assurance-boot-hab-i-mx8m-edition/ and eveything is working with a sigend uboot.

According to BoundaryDevices, they have been told by NXP that the next step is to get booti to auth the kernel by using this patch: https://github.com/boundarydevices/u-boot-imx6/commit/a20a5ee3c0 However, it's not working.

When I auth the kernel by hand using hab_auth_img, it appears to work just fine:

=> load mmc 1 ${loadaddr} Image
30009696 bytes read in 679 ms (42.1 MiB/s)
=> hab_auth_img ${loadaddr} ${filesize} 0x01c9d000

Authenticate image from DDR location 0x40480000...

Secure boot enabled

HAB Configuration: 0xcc, HAB State: 0x99
No HAB Events Found!

=>

But when just booting I get this:

Authenticating Image...

Authenticate image from DDR location 0x40800000...
Error: Invalid IVT structure

Allowed IVT structure:
IVT HDR = 0x4X2000D1
IVT ENTRY = 0xXXXXXXXX
IVT RSV1 = 0x0
IVT DCD = 0x0
IVT BOOT_DATA = 0xXXXXXXXX
IVT SELF = 0xXXXXXXXX
IVT CSF = 0xXXXXXXXX
IVT RSV2 = 0x0
Authenticate Image Fail, Please check
Error loading kernel image

And, of course, if I don't use the patch then it boots just fine, but I need to auth the kernel before leading.

What am I missing?

Re: Getting HAB to auth signed kernel on a MX8Mini

adam_m — Sat, 12 Dec 2020 01:06:32 GMT

I've done some digging and the issue seems to be that IVT_SEFT and IVT_INITAL don't match in validate_ivt(). I added some debuggin statements and found this:

Allowed IVT structure:
IVT HDR = 0x4X2000D1
IVT ENTRY = 0xXXXXXXXX
IVT RSV1 = 0x0
IVT DCD = 0x0
IVT BOOT_DATA = 0xXXXXXXXX
IVT SELF = 0xXXXXXXXX
IVT CSF = 0xXXXXXXXX
IVT RSV2 = 0x0
Found values:
IVT_ENTRY: 0x40480000
IVT_RSV1: 0x0
IVT_DCD: 0x0
IVT_SELF: 0x4211d000
IVT_INITAL: 0x4249d000
IVT_CSF: 0x4211d020
IVT_RSV2: 0x0

So, they are off by 0x380000 which is a suspiciously round number, but I can't figure out where it comes from.

Re: Getting HAB to auth signed kernel on a MX8Mini

Yuri — Tue, 15 Dec 2020 04:51:54 GMT

@adam_m
Hello,

Have You used recommendations in U-boot help how to sign kernel?

https://source.codeaurora.org/external/imx/uboot-imx/tree/doc/imx/habv4/guides/mx8m_mx8mm_secure_boot.txt?h=imx_v2018.03_4.14.78_1.0.0_ga

Regards,
Yuri.