From: Florian Fainelli <f.fainelli@xxxxxxxxx> On Fri, 4 Oct 2024 22:01:54 -0700, Sam Edwards <cfsworks@xxxxxxxxx> wrote: > The CFE bootloader places a stub program in the first page of physical > memory to hold the secondary CPUs until the boot CPU writes the release > address, but does not splice a /reserved-memory node into the FDT to > protect it. If Linux overwrites this program before execution reaches > smp_prepare_cpus(), the secondary CPUs may become inaccessible. > > This is only a problem with CFE, and then only until the secondary CPUs > are brought online. Ideally, there would be some hypothetical mechanism > we could use to indicate that this area of memory is sensitive only > during boot. But as there is none, and since it is such a small amount > of memory, it is easiest to reserve it unconditionally. > > Therefore, add a /reserved-memory node to bcm4908.dtsi to protect the > first 4KiB of physical memory. > > Signed-off-by: Sam Edwards <CFSworks@xxxxxxxxx> > --- Applied to https://github.com/Broadcom/stblinux/commits/devicetree-arm64/next, thanks! -- Florian
