[U-Boot] [PATCH 3/9] ARM: HYP/non-sec switch in bootm.c

[TigerLiu at viatech.com.cn]

Hi, Dall:
Thanks for your quick response!
>It depends on the board.  Which ARM doc are you referring to?
ARM Security Technology : Building a Secure System using TrustZone
Technology.
(PRD29-GENC-009492C)
Figure 5-2 in Chapter 5.2.1 Boot Sequence.
Based on my understanding, U-boot is classfied as normal world boot
loader.
Maybe my understanding is wrong! :)

>In general, there are three options for how u-boot is booted:
>1. In secure mode
>2. In non-secure hyp mode
>3. in non-secure svc mode

>for (1) you can just switch to non-secure hyp.  for (2) you don't have
>to do anything.  for (3) you're screwed, unless there's a backdoor
>call to enter Hyp mode (typically found on TI hardware).
For (1), i didn't get it totally:
On a platform with a CA7 supporting TZ tech, but this SOC not support
VT, 
usually cpu is powered on in secure mode.
So, i could only switch it to non-sec state?
If this CA7 also supports VT, so i could select 2 goals:
Switch to non-sec state, or swith to non-sec hyp mode?

I think non-sec state is not identical with non-sec hyp mode.

Best wishes,


-Christoffer