Messages in this thread | | | Subject | Re: [PATCH V2] ARM: dts: bcm283x: Reserve first page for firmware | From | Florian Fainelli <> | Date | Tue, 9 May 2017 09:25:54 -0700 |
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On 05/09/2017 02:04 AM, Phil Elwell wrote: > The Raspberry Pi startup stub files for multi-core BCM27XX processors > make the secondary CPUs spin until the corresponding mailbox is > written. These stubs are loaded at physical address 0x00000xxx (as seen > by the ARMs), but this page will be reused by the kernel unless it is > explicitly reserved, causing the waiting cores to execute random code. > > Use the /memreserve/ Device Tree directive to mark the first page as > off-limits to the kernel.
This reserves a 4KB page here, is this good enough, or should we just go directly to the maximum page granule size possible on an ARM64/Linux system to be on the safe side?
> > See: https://github.com/raspberrypi/linux/issues/1989 > > Signed-off-by: Phil Elwell <phil@raspberrypi.org> > --- > > Changes in V2: > - Rebase against linux-next > - Drop downstream-only patch > > arch/arm/boot/dts/bcm283x.dtsi | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/arm/boot/dts/bcm283x.dtsi b/arch/arm/boot/dts/bcm283x.dtsi > index a3106aa..6d12c3e8 100644 > --- a/arch/arm/boot/dts/bcm283x.dtsi > +++ b/arch/arm/boot/dts/bcm283x.dtsi > @@ -3,6 +3,8 @@ > #include <dt-bindings/clock/bcm2835-aux.h> > #include <dt-bindings/gpio/gpio.h> > > +/memreserve/ 0x00000000 0x00001000;
Can you put a comment above this /memreserve entry here to remind about what this is useful for?
Thanks!
> + > /* This include file covers the common peripherals and configuration between > * bcm2835 and bcm2836 implementations, leaving the CPU configuration to > * bcm2835.dtsi and bcm2836.dtsi. >
-- Florian
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