EFI stub loading support for RISC-V

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.

--
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 <[email protected]>

Cc Palmer Dabbelt <[email protected]>

Cc Paul Walmsley <[email protected]>

Cc Albert Ou <[email protected]>

Cc [email protected]

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

Quoted 18 lines · Ard Biesheuvel

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.

Quoted 3 lines

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.

Quoted 64 lines

--
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 <[email protected]>

Cc Palmer Dabbelt <[email protected]>

Cc Paul Walmsley <[email protected]>

Cc Albert Ou <[email protected]>

Cc [email protected]

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 +++

Quoted 8 lines

 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

Quoted 106 lines · Atish Patra

Quoted 18 lines · Ard Biesheuvel

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.

Quoted 3 lines

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.

Quoted 64 lines

--
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 <[email protected]>

Cc Palmer Dabbelt <[email protected]>

Cc Paul Walmsley <[email protected]>

Cc Albert Ou <[email protected]>

Cc [email protected]

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 +++

Quoted 8 lines

 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

Quoted 3 lines

--
Regards,
Atish

Hi Palmer,
There were few build errors for all-yes config and nommu reported by 0-day tests.
As some of the fixes require to add some dummy declarations for efi runtime related functions,
Ard suggested that we should drop the series for now and merge with full uefi support later.

Quoted 111 lines · On Tue, 28 Apr 2020 10:57:48 PDT (-0700), [email protected] wrote:

Quoted 106 lines · Atish Patra

Quoted 18 lines · Ard Biesheuvel

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.

Quoted 3 lines

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.

Quoted 64 lines

--
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 <[email protected]>

Cc Palmer Dabbelt <[email protected]>

Cc Paul Walmsley <[email protected]>

Cc Albert Ou <[email protected]>

Cc [email protected]

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 +++

Quoted 8 lines

 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

Quoted 3 lines

--
Regards,
Atish

Quoted 7 lines

Hi Palmer,
There were few build errors for all-yes config and nommu reported by 0-day tests.
As some of the fixes require to add some dummy declarations for efi runtime related functions,
Ard suggested that we should drop the series for now and merge with full uefi support later.

OK, I'll wait for another patch set. That makes my life a bit easier as well, as we don't have to do the multi-tree merge in a single release.

Quoted 121 lines · Palmer Dabbelt

Quoted 118 lines · On Tue, 28 Apr 2020 10:57:48 PDT (-0700), [email protected] wrote:

Quoted 106 lines · Atish Patra

Quoted 18 lines · Ard Biesheuvel

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.

Quoted 3 lines

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.

Quoted 64 lines

--
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 <[email protected]>

Cc Palmer Dabbelt <[email protected]>

Cc Paul Walmsley <[email protected]>

Cc Albert Ou <[email protected]>

Cc [email protected]

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 +++

Quoted 8 lines

 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

Quoted 3 lines

--
Regards,
Atish

Hi Palmer,
There were few build errors for all-yes config and nommu reported by 0-day tests.
As some of the fixes require to add some dummy declarations for efi runtime related functions,
Ard suggested that we should drop the series for now and merge with full uefi support later.

Quoted 2 lines

OK, I'll wait for another patch set. That makes my life a bit easier as well, as we don't have to do the multi-tree merge in a single release.

Yeah. Apologies for the back and forth, but I really don't want to end up in a place where I am juggling EFI fixes and have to care about architectures that can't even use EFI in a meaningful way.