On Wed, 23 Aug 2023 21:36:51 +0200 Jernej Škrabec <jernej.skrabec@xxxxxxxxx> wrote: Hi Andrey, > send new revision as standalone e-mail, not as reply to old discussion. > > Dne torek, 22. avgust 2023 ob 11:23:58 CEST je Andrey Skvortsov napisal(a): > > This patch reserves some memory in the DTS and sets up a > > pstore device tree node to enable pstore support. > > > > In general any DRAM address, that isn't overwritten during a boot is > > suitable for pstore. > > > > Range from 0x40000000 - 0x50000000 is heavily used by u-boot for > > internal use and to load kernel, fdt, fdto, scripts, pxefile and ramdisk > > later in the boot process. Ramdisk start address is 0x4FF00000, > > initramfs for kernel with some hacking features and debug info enabled > > can take more than 100Mb and final address will be around 0x58000000. > > Address 0x61000000 will most likely not overlap with that. > > There are other bootloaders as U-Boot, especially on PinePhone. Are you sure > it works there too? What about U-Boot configuration, will those addresses still > be used if configuration is changed? Also going along with what Pavel said (that's it more a policy decision, not a device property), I feel like this node should be added by the bootloader then. And indeed U-Boot has support for that already. >From skimming over the code in cmd/pstore.c: if you enable CONFIG_CMD_PSTORE and set CONFIG_CMD_PSTORE_MEM_ADDR to your chosen address, then the U-Boot code will insert a reserved memory node on the fly. Would that solve your problem? Cheers, Andre > Best regards, > Jernej > > > > > Signed-off-by: Andrey Skvortsov <andrej.skvortzov@xxxxxxxxx> > > --- > > > > Changes in v2: > > - Update commit description with information about why this base address is > > used. > > > > .../boot/dts/allwinner/sun50i-a64-pinephone.dtsi | 16 ++++++++++++++++ > > 1 file changed, 16 insertions(+) > > > > diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi > > b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi index > > 87847116ab6d..84f9410b0b70 100644 > > --- a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi > > +++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi > > @@ -19,6 +19,22 @@ aliases { > > serial0 = &uart0; > > }; > > > > + reserved-memory { > > + #address-cells = <1>; > > + #size-cells = <1>; > > + ranges; > > + > > + pstore_mem: ramoops@61000000 { > > + compatible = "ramoops"; > > + reg = <0x61000000 0x100000>; > > + record-size = <0x20000>; > > + console-size = <0x20000>; > > + ftrace-size = <0x20000>; > > + pmsg-size = <0x20000>; > > + ecc-size = <16>; > > + }; > > + }; > > + > > backlight: backlight { > > compatible = "pwm-backlight"; > > pwms = <&r_pwm 0 50000 PWM_POLARITY_INVERTED>; > > > > >