> 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-$(CONFIG_ARCH_SUNPLUS) := 0x00308000
> > >
> > > What is this needed for? If it boots without this line, better avoid
> > > adding it, because
> > > it will increase the kernel size for everyone else (unless they also enable
> > > AXXIA).
> > >
> >
> > SP7021 reserved the 1st 1MB memory for ARM926@P-Chip using,
> > The 2nd 1MB memory for IOP device and the 3rd 1MB memory for bootloader.
> > I'll add these comments at next commit.
>
> I think you can just remove the memory from the system memory map in the
> device tree and pretend it only starts after the bootloader. It's been a while
> since I looked at this though, so I could be misremembering what the minimum
> boundaries are for doing this.
>
> Arnd
I have test following 3 methods:
1. current patch
DT:
memory {
reg = <0x00000000 0x20000000>; /* 512MB */
};
reserved-memory {
#address-cells = <1>;
#size-cells = <1>;
ranges;
iop_reserve: iop_device {
no-map;
reg = <0x00100000 0x00100000>;
};
a926_reserve: a926_memory {
no-map;
reg = <0x00000000 0x00100000>;
};
};
arch/arm/Makefile:
textofs-$(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).
