+Ard On Tue, Jun 15, 2021 at 5:29 PM Nick Kossifidis <mick@xxxxxxxxxxxx> wrote: > > Στις 2021-06-15 22:21, Rob Herring έγραψε: > > On Tue, Jun 15, 2021 at 12:48 PM Geert Uytterhoeven > > <geert@xxxxxxxxxxxxxx> wrote: > >> > >> Hi Nick, > >> > >> On Tue, Jun 15, 2021 at 8:29 PM Nick Kossifidis <mick@xxxxxxxxxxxx> > >> wrote: > >> > Στις 2021-06-15 16:19, Geert Uytterhoeven έγραψε: > >> > > This does not match > >> > > https://github.com/devicetree-org/dt-schema/blob/master/schemas/chosen.yaml#L77: > >> > > > >> > > $ref: types.yaml#/definitions/uint64-array > >> > > maxItems: 2 > >> > > description: > >> > > This property (currently used only on arm64) holds the memory > >> > > range, > >> > > the address and the size, of the elf core header which mainly > >> > > describes > >> > > the panicked kernel\'s memory layout as PT_LOAD segments of elf > >> > > format. > >> > > > >> > > Hence "linux,elfcorehdr" should be a property of the /chosen node, > >> > > instead of a memory node with a compatible value of "linux,elfcorehdr". > >> > > > >> > > >> > That's a binding for a property on the /chosen node, that as the text > >> > says it's defined for arm64 only and the code that handled it was also > >> > >> That doesn't mean it must not be used on other architectures ;-) > >> Arm64 was just the first one to use it... > > > > It is used on arm64 because memory is often passed by UEFI tables and > > not with /memory node. As riscv is also supporting EFI, I'd think they > > would do the same. > > > > We've had this discussion before, riscv uses /memory for now and even if > we switched to getting memory from ACPI/UEFI tables, the elf core header > is passed from the crashed kernel to the kdump kernel, it has nothing to > do with UEFI since the bootloader is the kernel itself. Am I missing > something ? I believe if we originally booted using UEFI tables, then those are passed the kdump kernel as well. The original DT may have had a /memory node, but it's possible it didn't match what was in the UEFI tables. So using the DT /memory nodes for kdump could give surprising results. I think reserved regions also come from UEFI. Ard can probably comment better. Rob