On Sat, Apr 25, 2020 at 12:31 PM Ard Biesheuvel <ardb@xxxxxxxxxx> wrote: > > Palmer, > > As discussed, below are the changes for v5.8 that can be taken via the > RISC-V tree to implement booting RISC-V Linux from EFI firmware. > > You can fetch and merge the signed tag directly, or merge 22090f84bc3f80 > and cherry pick the 4 patches on top of it, if you see any need to do so > (but please use a topic branch in that case) > > Please be aware (as is noted in the tag) that these changes are really > the bare minimum that is needed to launch the kernel from EFI firmware. > In the current state, you may be able to boot from Uboot in EFI mode, > but Tianocore based boot will not work at all, unless you convert the > EFI memory map back to DT memory nodes in the firmware implementation, > and I can assure you that that is not something that will be accepted in > upstream Tianocore. > > So in summary, this is unfinished work, and I can only recommend merging > these changes once there is a plan in place to complete the implementation. > I have started looking into this part. My initial plan was to start looking into it right after I got the boot time services working but other things took priority. Thanks for your review and suggestion throughout the process. I will coordinate with Abner/Daniel to test RISC-V UEFI runtime services(once implemented) with tianocore. > -- > Ard. > > > The following changes since commit 22090f84bc3f8081e0ec180ccaedc85820085376: > > efi/libstub: unify EFI call wrappers for non-x86 (2020-04-23 20:15:06 +0200) > > are available in the Git repository at: > > git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi.git tags/riscv-efi-for-v5.8 > > for you to fetch changes up to 66b4ac6b9dd1fdbb8ac7a1f20a8d08066368245d: > > RISC-V: Add EFI stub support. (2020-04-25 13:59:54 +0200) > > ---------------------------------------------------------------- > EFI stub loading support for RISC-V > > This branch implements support for loading the RISC-V Linux kernel > straight from EFI firmware, by adding PE/COFF metadata to the kernel > image and incorporating the kernel's EFI stub. > > Note that this is the *bare* minimum that is needed to boot from EFI > firmware. The following pieces are still missing at this point, and > will be required for full interoperability with generic EFI firmware: > - using the EFI memory map instead of the device tree to populate the > memblock tables > - parsing and handling of generic EFI configuration tables (such as > SMBIOS), as well as architecture specific ones that may be defined > for RISC-V > - runtime mapping of EFI runtime services memory and MMIO regions, and > support for EFI runtime services (get/set time, get/set variable, reset > system) > > ---------------------------------------------------------------- > > Cc: Atish Patra <atish.patra@xxxxxxx> > Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx> > Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx> > Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx> > Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx > > Atish Patra (4): > include: pe.h: Add RISC-V related PE definition > RISC-V: Define fixmap bindings for generic early ioremap support > RISC-V: Add PE/COFF header for EFI stub > RISC-V: Add EFI stub support. > > arch/riscv/Kconfig | 22 ++++++ > arch/riscv/Makefile | 1 + > arch/riscv/configs/defconfig | 1 + > arch/riscv/include/asm/Kbuild | 1 + > arch/riscv/include/asm/efi.h | 33 +++++++++ > arch/riscv/include/asm/fixmap.h | 18 +++++ > arch/riscv/include/asm/io.h | 1 + > arch/riscv/include/asm/sections.h | 13 ++++ > arch/riscv/kernel/Makefile | 4 ++ > arch/riscv/kernel/efi-header.S | 100 +++++++++++++++++++++++++++ > arch/riscv/kernel/head.S | 16 +++++ > arch/riscv/kernel/image-vars.h | 53 +++++++++++++++ > arch/riscv/kernel/vmlinux.lds.S | 22 +++++- > drivers/firmware/efi/Kconfig | 3 +- > drivers/firmware/efi/libstub/Makefile | 10 +++ > drivers/firmware/efi/libstub/riscv-stub.c | 109 ++++++++++++++++++++++++++++++ > include/linux/pe.h | 3 + > 17 files changed, 407 insertions(+), 3 deletions(-) > create mode 100644 arch/riscv/include/asm/efi.h > create mode 100644 arch/riscv/include/asm/sections.h > create mode 100644 arch/riscv/kernel/efi-header.S > create mode 100644 arch/riscv/kernel/image-vars.h > create mode 100644 drivers/firmware/efi/libstub/riscv-stub.c -- Regards, Atish
