On Thu, Dec 9, 2021 at 9:49 AM qinjian[覃健] <qinjian@xxxxxxxxxxx> wrote:
> > On Tue, Dec 7, 2021 at 8:21 AM qinjian[覃健] <qinjian@xxxxxxxxxxx> wrote:
> > > > > @@ -152,6 +152,7 @@ textofs-$(CONFIG_ARCH_MSM8X60) := 0x00208000
> > > > > textofs-$(CONFIG_ARCH_MSM8960) := 0x00208000
> > > > > textofs-$(CONFIG_ARCH_MESON) := 0x00208000
> > > > > textofs-$(CONFIG_ARCH_AXXIA) := 0x00308000
> > > > > +textofs-$(CONFIG_ARCH_SUNPLUS) := 0x00308000
> > > >
> > > > What is this needed for? If it boots without this line, better avoid
> > > > adding it, because
> > > > it will increase the kernel size for everyone else (unless they also enable
> > > > AXXIA).
> > > >
> > >
> > > SP7021 reserved the 1st 1MB memory for ARM926@P-Chip using,
> > > The 2nd 1MB memory for IOP device and the 3rd 1MB memory for bootloader.
> > > I'll add these comments at next commit.
> >
> > I think you can just remove the memory from the system memory map in the
> > device tree and pretend it only starts after the bootloader. It's been a while
> > since I looked at this though, so I could be misremembering what the minimum
> > boundaries are for doing this.
>
> I have test following 3 methods:
Right, I was thinking of the third method here, which has the advantage of
not requiring the same odd base address for all other platforms, this
is important to us.
I don't see what the problem is with it in your example, does that mean you
have a little less usable memory, or that something fails to work right? I don't
know what the requirements are for memreserve.
Adding a few more people to Cc, maybe they have ideas about how this
was solved elsewhere.
Arnd
> 1. current patch
> DT:
> memory {
> reg = <0x00000000 0x20000000>; /* 512MB */
> };
>
> reserved-memory {
> #address-cells = <1>;
> #size-cells = <1>;
> ranges;
>
> iop_reserve: iop_device {
> no-map;
> reg = <0x00100000 0x00100000>;
> };
> a926_reserve: a926_memory {
> no-map;
> reg = <0x00000000 0x00100000>;
> };
> };
> arch/arm/Makefile:
> textofs-$(CONFIG_ARCH_SUNPLUS) := 0x00308000
>
> bootlog & meminfo :
> [ 0.000000] Zone ranges:
> [ 0.000000] Normal [mem 0x0000000000000000-0x000000001fffffff]
> [ 0.000000] Movable zone start for each node
> [ 0.000000] Early memory node ranges
> [ 0.000000] node 0: [mem 0x0000000000000000-0x00000000001fffff]
> [ 0.000000] node 0: [mem 0x0000000000200000-0x000000001fffffff]
> [ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x000000001fffffff]
>
> ~ # cat /proc/meminfo
> MemTotal: 514008 kB
> MemFree: 491960 kB
> MemAvailable: 488608 kB
>
>
>
> 2. DT same as case 1, but no modify @ arch/arm/Makefile
>
> bootlog & meminfo :
> [ 0.000000] OF: fdt: Reserved memory: failed to reserve memory for node 'iop_device': base 0x00100000, size 1 MiB
> [ 0.000000] OF: fdt: Reserved memory: failed to reserve memory for node 'a926_memory': base 0x00000000, size 1 MiB
> ...
> [ 0.000000] Zone ranges:
> [ 0.000000] Normal [mem 0x0000000000000000-0x000000001fffffff]
> [ 0.000000] Movable zone start for each node
> [ 0.000000] Early memory node ranges
> [ 0.000000] node 0: [mem 0x0000000000000000-0x000000001fffffff]
> [ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x000000001fffffff]
>
> ~ # cat /proc/meminfo
> MemTotal: 516056 kB
> MemFree: 493928 kB
> MemAvailable: 490572 kB
>
>
>
> 3. DT:
> memory {
> reg = <0x00300000 0x1FD00000>; /* 512 - 3 MB */
> };
> no modify @ arch/arm/Makefile
>
> bootlog & meminfo :
> [ 0.000000] Zone ranges:
> [ 0.000000] Normal [mem 0x0000000000400000-0x000000001fffffff]
> [ 0.000000] Movable zone start for each node
> [ 0.000000] Early memory node ranges
> [ 0.000000] node 0: [mem 0x0000000000400000-0x000000001fffffff]
> [ 0.000000] Initmem setup node 0 [mem 0x0000000000400000-0x000000001fffffff]
>
> ~ # cat /proc/meminfo
> MemTotal: 511964 kB
> MemFree: 489636 kB
> MemAvailable: 486292 kB
>
>
>
> I think method 1 should be correct (compare method 2) & better (compare method 3).
>
