Re: raspberry pi 4 arm64 test image

On Wed, 21 Aug 2019 23:59:28 +0200 [email protected] wrote:
[email protected] writes:
> > The firmware on a pi4 with 2GB or 4GB RAM will only report 1GB.
> > I believe you need to look at the board id (or probe for invalid
> > addresses as in the teg2 kernel) to find out the real amount.
>
> oh dear. i dont even know the expected physical memory map...
> i guess that ram is continuous block at [0-0xfc000000). but
> some memory might be reserved...
>
> on what method does it report only 1GB?
>
> i know of 3 methods so far:
>
> - atags
> - device tree /memory/reg property
> - firmware property request (getramsize() in vcore.c)
>
> for me getramsize() returns zero for both base and limit so its
> completely useless.
>
> i'm currently using device tree method, but the code assumes that
> there is a single block entry. lets see if that lies as well with
> the debug kernel.

The device tree has two entries.

offset:0
lenght:0x3c400000

offset:0x40000000
length:0xbc000000