[U-Boot] [U-Boot PATCH v2 08/12] k2hk: add support for k2hk SOC and EVM

Andrianov, Vitaly
2014-03-06T19:09:18Z

Hi Tom,

> -----Original Message-----
> From: u-boot-bounces at lists.denx.de [mailto:u-boot-
> bounces at lists.denx.de] On Behalf Of Rini, Tom
> Sent: Tuesday, February 25, 2014 5:12 PM
> To: Karicheri, Muralidharan
> Cc: Kwok, WingMan; u-boot at lists.denx.de; Nair, Sandeep
> Subject: Re: [U-Boot] [U-Boot PATCH v2 08/12] k2hk: add support for
> k2hk SOC and EVM
>
> On Thu, Feb 20, 2014 at 12:55:10PM -0500, Murali Karicheri wrote:
>
> > From: Vitaly Andrianov <vitalya@ti.com>
> >
> > k2hk EVM is based on Texas Instruments Keystone2 Hawking/Kepler SoC.
> > Keystone2 SoC has ARM v7 Cortex-A15 MPCore processor. Please refer
> the
> > ti/k2hk_evm/README for details on the board, build and other
> > information.
> >
> > This patch add support for keystone architecture and k2hk evm.
> >
> > Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
> > Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
> > Signed-off-by: WingMan Kwok <w-kwok2@ti.com>
> > Signed-off-by: Sandeep Nair <sandeep_n@ti.com>

[snip]
>
> > + "fdt_high=0xffffffff\0" \
>
> Please don't do this, set it to the top of kernel low mem.
>

The EVM may have up to 8GB of DDR and u-boot can see the first 2GB
with physical address range 0x80000000-0xffffffff.
If we don't use the "fdt_high" environment variable, u-boot relocates
the dtb to the end of that memory, which is outside of the lowmem.

Here is the part of bootlog:
-------------------------------------------------------------
## Flattened Device Tree blob at 87000000
Booting using the fdt blob at 0x87000000
Loading Kernel Image ... OK
OK
Loading Device Tree to ffff1000, end fffffcab ... OK
--------------------------------------------------------------

But K2 lowmem VA starts from 0xc0000000 and has size ~760MB. That
corresponds to the physical range 0x80000000-0xaf800000.
That is why we have to use the "fdt_high=0xffffffff" environment variable.

Have I missed something I u-boot memory configuration?
Is there a way to tell u-boot to relocate fdt to the end lowmem?

Thanks,
Vitaly