On Wed, Sep 9, 2020 at 1:52 PM Palmer Dabbelt <palmer@xxxxxxxxxxx> wrote: > > On Wed, 09 Sep 2020 08:16:20 PDT (-0700), ardb@xxxxxxxxxx wrote: > > Maxim reports boot failures on platforms that describe reserved memory > > regions in DT that are disjoint from system DRAM, and which are converted > > to EfiReservedMemory regions by the EFI subsystem in u-boot. > > > > As it turns out, the whole notion of discovering the base of DRAM is > > problematic, and it would be better to simply rely on the EFI memory > > allocation routines instead, and derive the FDT and initrd allocation > > limits from the actual placement of the kernel (which is what defines > > the start of the linear region anyway) > > > > Finally, we should be able to get rid of get_dram_base() entirely. > > However, as RISC-V only just started using it, we will need to address > > that at a later time. > > Looks like we're using dram_base to derive two argumets to > efi_relocate_kernel(): the preferred load address and the minimum load address. > I don't see any reason why we can't use the same PAGE_OFFSET-like logic that > x86 uses for the minimum load address, but I don't think we have any mechanism > like "struct boot_params" so we'd need to come up with something. > As discussed in the other thread (https://www.spinics.net/lists/linux-efi/msg20262.html), we don't need to do anything special. efi_relocate_kernel can just take preferred address as 0 so that efi_bs_alloc will fail and efi_low_alloc_above will be used to allocate 2MB/4MB aligned address as per requirement. I don't think the other changes in this series will cause any issue for RISC-V. I will test it and update anyways. > > Cc: Maxim Uvarov <maxim.uvarov@xxxxxxxxxx> > > Cc: Heinrich Schuchardt <xypron.glpk@xxxxxx> > > Cc: Atish Patra <atish.patra@xxxxxxx> > > Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx> > > Cc: Jens Wiklander <jens.wiklander@xxxxxxxxxx> > > Cc: Francois Ozog <francois.ozog@xxxxxxxxxx> > > Cc: Etienne CARRIERE <etienne.carriere@xxxxxx> > > Cc: Takahiro Akashi <takahiro.akashi@xxxxxxxxxx> > > Cc: Patrice CHOTARD <patrice.chotard@xxxxxx> > > Cc: Sumit Garg <sumit.garg@xxxxxxxxxx> > > Cc: Grant Likely <Grant.Likely@xxxxxxx> > > Cc: Ilias Apalodimas <ilias.apalodimas@xxxxxxxxxx> > > Cc: Christophe Priouzeau <christophe.priouzeau@xxxxxxxxxx> > > Cc: Rouven Czerwinski <r.czerwinski@xxxxxxxxxxxxxx> > > Cc: Patrick DELAUNAY <patrick.delaunay@xxxxxx> > > > > Ard Biesheuvel (3): > > efi/libstub: Export efi_low_alloc_above() to other units > > efi/libstub: Use low allocation for the uncompressed kernel > > efi/libstub: base FDT and initrd placement on image address not DRAM > > base > > > > arch/arm/include/asm/efi.h | 6 +- > > arch/arm64/include/asm/efi.h | 2 +- > > drivers/firmware/efi/libstub/arm32-stub.c | 177 ++++---------------- > > drivers/firmware/efi/libstub/efi-stub.c | 2 +- > > drivers/firmware/efi/libstub/efistub.h | 3 + > > drivers/firmware/efi/libstub/relocate.c | 4 +- > > 6 files changed, 47 insertions(+), 147 deletions(-) -- Regards, Atish
