Re: [edk2-devel] [edk2-staging/RISC-V-V2 PATCH v3 37/39] edk2-staging:RISC-V-V2: Add RiscVEdk2Readme.md

["Abner Chang" <abner.chang@hpe.com>]

> -----Original Message-----
> From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of
> Leif Lindholm
> Sent: Friday, November 22, 2019 1:09 AM
> To: Chang, Abner (HPS SW/FW Technologist) <abner.chang@hpe.com>
> Cc: devel@edk2.groups.io; Chen, Gilbert <gilbert.chen@hpe.com>
> Subject: Re: [edk2-devel] [edk2-staging/RISC-V-V2 PATCH v3 37/39] edk2-
> staging:RISC-V-V2: Add RiscVEdk2Readme.md
> 
> On Mon, Oct 28, 2019 at 09:59:15 +0800, Abner Chang wrote:
> > Add readme of RISC-V edk2 port.
> >
> > Signed-off-by: Abner Chang <abner.chang@hpe.com>
> >
> > Cc: Leif Lindholm <leif.lindholm@linaro.org>
> > Cc: Gilbert Chen <gilbert.chen@hpe.com>
> > ---
> >  RiscVEdk2Readme.md | 64
> > ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 64 insertions(+)
> >  create mode 100644 RiscVEdk2Readme.md
> >
> > diff --git a/RiscVEdk2Readme.md b/RiscVEdk2Readme.md new file mode
> > 100644 index 0000000..ebd7495
> > --- /dev/null
> > +++ b/RiscVEdk2Readme.md
> > @@ -0,0 +1,64 @@
> > +This branch is used to contribute RISC-V architecture to EDK2
> > +
> > +The branch owner:
> > +Abner Chang < abner.chang@hpe.com >
> > +Gilbert Chen < gilbert.chen@hpe.com >
> > +
> > +## RISC-V EDK2 Port Introduction
> > +RISC-V is an open ISA which was designed to support research and
> > +education of computer architecture, but now it becomes a standard
> > +open Instruction Set Architecture for industry implementations. The
> > +RISC-V edk2 project is to create a new processor binding in UEFI spec and
> have the RISC-V edk2 implementation.
> > +The goal is to have RISC-V edk2 port as the firmware reference for
> > +RISC-V platforms.
> > +
> > +This branch (RISC-V-V2) on edk2-staging is RISC-V edk2 port with
> > +RISC-V OpenSbi (https://github.com/riscv/opensbi) library integrated.
> > +RiscVPkg provides the generic and common modules of RISC-V prcessor.
> > +Two edk2 RISC-V platforms are introduced in this branch,
> > +- SiFive Freedome U500 platform whcih is maintained in
> > +FreedomU500VC707Board under Platform/SiFive/U5SeriesPkg.
> > +- SiFive Freedome U540 HiFive Unleashed platform whcih is maintained
> > +in FreedomU540HiFiveUnleashedBoard under
> Platform/SiFive/U5SeriesPkg.
> > +
> > +Refer to Platform/SiFive/U5Series/Readme.md on edk2-platform
> repository.
> > +
> > +## RISC-V EDK2 Package
> > +```
> > +RiscVPkg       - RISC-V processor package. This package provides RISC-V
> > +                 processor related protocols/libraries accroding to UEFI
> > +                 specification and edk2 implementations.
> > +RiscVPlatformPkg  - RISC-V platform package. This package provides RISC-
> V
> > +                    platform common modules, libraries, PCDs and definitoins.
> > +```
> > +## Toolchain of RISC-V EDK2 port
> > +Due to not yet tracked down bugs, only the following toolchain is
> > +known to produce bootoable binaries.
> 
> Was this issue also resolved by Mark's linker script patch?

The fix is not in lds, the fix is tool_def.template in which msmall-data-limit is added and set to 0 to avoid .sdata2 section. See below email on edk2-devel,
- [edk2-devel] [edk2-staging/RISC-V-V2 PATCH v3-2] BaseTools: Fix edk2 RISC-V binary hangs at POST with the latest toolchain

> 
> > +https://github.com/riscv/riscv-gnu-toolchain at commit ID 64879b24.
> > +The commit ID 64879b24 of riscv-gnu-toolchain repository is verified
> > +to build RISC-V edk2 platform and boot to EFI SHELL successfully.
> > +You have to clone the toolchain from above link and check out
> > +commit:64879b24 for building RISC-V edk2 port.
> > +The commit later than 64879b24 causes system hangs at the PEI phase
> > +to DXE phase transition. We are still figuring out the root cause.
> > +
> > +## EDK2 Build Target
> > +"RISCV64" ARCH is the RISC-V architecture which currently supported and
> verified.
> > +The verified RISC-V toolchain is
> > +https://github.com/riscv/riscv-gnu-toolchain
> > +@64879b24 as mentioned above, toolchain tag is "GCC5" which is
> > +declared in tools_def.txt.
> 
> If this text is still needed:
> Which environment has this toolchain successfully been built in?

Readme has been updated,
https://github.com/riscv/riscv-gnu-toolchain and "GCC5" till the toolchain used for building binary of RISC-V platform, just commit ID 64879b24 is not required.

- [edk2-devel] [Platform/devel-riscv-v2 PATCHv5-2] edk2-platforms: Update Readme.md for RISC-V platform.
- [edk2-devel] [edk2-staging/RISC-V-V2 PATCH v3-2] BaseTools: Fix edk2 RISC-V binary hangs at POST with the latest toolchain


> 
> /
>     Leif
> 
> > +Below is the edk2 build options for building RISC-V RV64 platform,
> > +``` build -a RISCV64 -p Platform/{Vendor}/{Platform}/{Platform}.dsc
> > +-t GCC5 ``` For example, ``` build -a RISCV64 -p
> > +Platform/SiFive/U5SeriesPkg/FreedomU500VC707Board/U500.dsc
> > +-t GCC5
> > +```
> > +
> > +Make sure RISC-V toolchain is built succesfully and the toolchain
> > +binaries are generated in somewhere you specified when building
> toolchain.
> > +'GCC5_RISCV64_PREFIX' is the cross compilation prefix to toolchain
> binraries.
> > +For example, set 'GCC5_RISCV64_PREFIX' to '~/RiscVToolchain/riscv64-
> unknown-elf-'
> > +before you build RISC-V edk2 port.
> > --
> > 2.7.4
> >
> 
>