memory size in tz_vmm

Martin Stein martin.stein at genode-labs.com
Thu Nov 1 12:31:46 CET 2018


Hi,

First something off-topic: It seems that you have set "respond-to" to be
only your own mail address. If so, could you please refrain from this in
the future? At least to me, it seems a bit annoying to have to check the
receiver manually each time.

Now to your question:

Its not that much of information but here is what I vaguely remember:

1) Normally, there are certain limitations to RAM partitioning in
Trustzone. So you can't choose freely how much of the RAM should be
trusted and how much not. I can't tell how the limitations looked like
in particular but I remember that it was important to take care of them
when configuring.

2) The means of Trustzone configuration are pretty implementer-specific
You may want to have a look at [1], [2], and [3] to see how
Trustzone-relevant stuff is initialized by base-hw on IMX.

3) There's some documentation about AIPSTZ and CSU in [4], [5].

I hope this helps.

Cheers,
Martin

[1] <GENODE_DIR>(repos/base-hw/src/bootstrap/spec/arm/imx_aipstz
[2] <GENODE_DIR>(repos/base-hw/src/bootstrap/spec/arm/imx_csu
[3] <GENODE_DIR>(repos/base-hw/src/bootstrap/spec/arm/imx_tzic
[4] https://www.nxp.com/docs/en/reference-manual/iMX53RM.pdf
[5] https://www.nxp.com/docs/en/reference-manual/IMX53RQSBRM-R.pdf


El 21/09/18 a las 15:39, lzSun escribió:
> Hello,
> I am very interested in genode and I am working on tz_vmm demo using
> i.mx53-qsb board now. After the tz_vmm start,  I find a boot message
> like this:
> " Genode 18.05 <local changes>
> 211 MiB RAM and 64535 caps assigned to init "
> To my understanding, it's present that the available memory that the
> genode os in secure world is 211MB. And After the system boot up, I use
> Top command to observe the memroy that normal world have which gives me
> like this:
> " Mem: 37956K used, 49444K free, 0K shrd, 68K buff, 26456K cached "
> This shows that the total memory the linux in the normal world can use
> is less than 150MB. And I have some questions about this:
> 1. Can this memory size be increased? For example, I want to increase
> the memory size that genode can use. To my understanding, this memory
> distribution between two worlds(secure and normal) can be configured. So
> I wonder whether I can determine 
> this memory distribution. If it's indeed configurable,  where I can find
> the source file to configure this and whether this configuration can be
> changed dynamically when the system is running. 
> 2. As far as I know, the i.mx53-qsb have 1GB, but from the situation
> above, the total memory size is about 400MB which is far less than 1GB.
> So why can this situation happened?
> Thanks,
> Best wishes



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