Re: [edk2-devel] [RESEND PATCH v2] BaseTools: Add support for RISCV GOT/PLT relocations

["Sunil V L" <sunilvl@ventanamicro.com>]

Hi Pete,
   Thank you very much!.
On Wed, Jun 16, 2021 at 01:35:27PM +0100, Pete Batard wrote:
> Sunil, Daniel, thanks for the patch.
> 
> I confirm that this addresses the 0x13 and 0x14 relocation issues that I was
> seeing.
> 
> However, this patch appears to introduces new R_RISCV_PCREL_LO12_S
> relocation errors that I was not seeing previously, so I still can't manage
> to get a successful compilation.

It is not introduced by the patch but looks like one more new relocation
type is added by the latest tool chain you are using. Please raise a new
bug and I will add the support for it in next patch.

Thanks!
Sunil
> 
> Especially the stream of 0x13 and 0x14 relocation errors I was getting at
> https://github.com/pbatard/ntfs-3g/runs/2278190652?check_suite_focus=true
> has now switched to (tested on up to date Ubuntu with latest EDK2):
> 
> -------------------------------------------------------------------------
> "GenFw" -e UEFI_DRIVER -o /usr/src/ntfs-3g/Build/RELEASE_GCC5/RISCV64/uefi-driver/uefi_driver/OUTPUT/ntfs.efi /usr/src/ntfs-3g/Build/RELEASE_GCC5/RISCV64/uefi-driver/uefi_driver/DEBUG/ntfs.dll
> GenFw: ERROR 3000: Invalid
>   WriteSections64(): /usr/src/ntfs-3g/Build/RELEASE_GCC5/RISCV64/uefi-driver/uefi_driver/DEBUG/ntfs.dll
> unsupported ELF EM_RISCV64 relocation 0x19.
> GenFw: ERROR 3000: Invalid
>   WriteSections64(): /usr/src/ntfs-3g/Build/RELEASE_GCC5/RISCV64/uefi-driver/uefi_driver/DEBUG/ntfs.dll
> unsupported ELF EM_RISCV64 relocation 0x19.
> GenFw: ERROR 3000: Invalid
>   WriteSections64(): /usr/src/ntfs-3g/Build/RELEASE_GCC5/RISCV64/uefi-driver/uefi_driver/DEBUG/ntfs.dll
> unsupported ELF EM_RISCV64 relocation 0x19.
> GenFw: ERROR 3000: Invalid
>   WriteRelocations64(): /usr/src/ntfs-3g/Build/RELEASE_GCC5/RISCV64/uefi-driver/uefi_driver/DEBUG/ntfs.dll
> unsupported ELF EM_RISCV64 relocation 0x19.
> GenFw: ERROR 3000: Invalid
>   WriteRelocations64(): /usr/src/ntfs-3g/Build/RELEASE_GCC5/RISCV64/uefi-driver/uefi_driver/DEBUG/ntfs.dll
> unsupported ELF EM_RISCV64 relocation 0x19.
> GenFw: ERROR 3000: Invalid
>   WriteRelocations64(): /usr/src/ntfs-3g/Build/RELEASE_GCC5/RISCV64/uefi-driver/uefi_driver/DEBUG/ntfs.dll
> unsupported ELF EM_RISCV64 relocation 0x19.
> make: *** [GNUmakefile:553: /usr/src/ntfs-3g/Build/RELEASE_GCC5/RISCV64/uefi-driver/uefi_driver/OUTPUT/ntfs.efi]
> Error 2
> -------------------------------------------------------------------------
> 
> So, in effect, some of the earlier relocation errors appear to have morphed
> into 0x19/R_RISCV_PCREL_LO12_S ones...
> 
> I can open a new bug for this issue if you prefer.
> 
> Regards,
> 
> /Pete
> 
> On 2021.06.15 03:26, Daniel Schaefer wrote:
> > Great commit message, thanks Sunil!
> > Maintainers, please take a look and let us know if there's any other
> > concern.
> > This patch lets us build the RISC-V platforms using modern toolchains
> > that are provided directly by the distributions, rather than building
> > your own from source.
> > 
> > Thanks,
> > Daniel
> > ------------------------------------------------------------------------
> > *From:* Sunil V L <sunilvl@ventanamicro.com>
> > *Sent:* Friday, June 11, 2021 22:08
> > *To:* devel@edk2.groups.io <devel@edk2.groups.io>
> > *Cc:* Chang, Abner (HPS SW/FW Technologist) <abner.chang@hpe.com>;
> > Schaefer, Daniel <daniel.schaefer@hpe.com>; Bob Feng
> > <bob.c.feng@intel.com>; Liming Gao <gaoliming@byosoft.com.cn>; Yuwei
> > Chen <yuwei.chen@intel.com>; Heinrich Schuchardt <xypron.glpk@gmx.de>
> > *Subject:* Re: [RESEND PATCH v2] BaseTools: Add support for RISCV
> > GOT/PLT relocations
> > Hi,
> >      I just edited the commit message to indicate the module and CC the
> >      maintainers. Could I get the feedback please?
> > Thanks
> > Sunil
> > 
> > On Fri, Jun 11, 2021 at 07:35:03PM +0530, Sunil V L wrote:
> > > Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3096
> > <https://bugzilla.tianocore.org/show_bug.cgi?id=3096>
> > > 
> > > This patch adds support for R_RISCV_CALL_PLT and R_RISCV_GOT_HI20
> > > relocations generated by PIE enabled compiler. This also needed
> > > changes to R_RISCV_32 and R_RISCV_64 relocations as explained in
> > > https://github.com/riscv/riscv-gnu-toolchain/issues/905#issuecomment-846682710
> > <https://github.com/riscv/riscv-gnu-toolchain/issues/905#issuecomment-846682710>
> > > 
> > > Changes in v2:
> > >    - Addressed Daniel's comment on formatting
> > > 
> > > Testing:
> > > 1) Debian GCC 8.3.0 and booted sifive_u and QMEU virt models.
> > > 2) Debian 10.2.0 and booted QEMU virt model.
> > > 3) riscv-gnu-tool chain 9.2 and booted QEMU virt model.
> > > 
> > > Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
> > > 
> > > Acked-by: Abner Chang <abner.chang@hpe.com>
> > > Reviewed-by: Daniel Schaefer <daniel.schaefer@hpe.com>
> > > Tested-by: <daniel.schaefer@hpe.com>
> > > 
> > > Cc: Bob Feng <bob.c.feng@intel.com>
> > > Cc: Liming Gao <gaoliming@byosoft.com.cn>
> > > Cc: Yuwei Chen <yuwei.chen@intel.com>
> > > Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
> > > ---
> > >   BaseTools/Source/C/GenFw/Elf64Convert.c | 44 +++++++++++++++++++++----
> > >   1 file changed, 38 insertions(+), 6 deletions(-)
> > > 
> > > diff --git a/BaseTools/Source/C/GenFw/Elf64Convert.c b/BaseTools/Source/C/GenFw/Elf64Convert.c
> > > index d097db8632..d684318269 100644
> > > --- a/BaseTools/Source/C/GenFw/Elf64Convert.c
> > > +++ b/BaseTools/Source/C/GenFw/Elf64Convert.c
> > > @@ -129,6 +129,8 @@ STATIC UINT32 mDebugOffset;
> > >   STATIC UINT8       *mRiscVPass1Targ = NULL;
> > >   STATIC Elf_Shdr    *mRiscVPass1Sym = NULL;
> > >   STATIC Elf64_Half  mRiscVPass1SymSecIndex = 0;
> > > +STATIC INT32       mRiscVPass1Offset;
> > > +STATIC INT32       mRiscVPass1GotFixup;
> > >   //
> > >   // Initialization Function
> > > @@ -479,11 +481,11 @@ WriteSectionRiscV64 (
> > >       break;
> > >     case R_RISCV_32:
> > > -    *(UINT32 *)Targ = (UINT32)((UINT64)(*(UINT32 *)Targ) - SymShdr->sh_addr + mCoffSectionsOffset[Sym->st_shndx]);
> > > +    *(UINT64 *)Targ = Sym->st_value + Rel->r_addend;
> > >       break;
> > >     case R_RISCV_64:
> > > -    *(UINT64 *)Targ = *(UINT64 *)Targ - SymShdr->sh_addr + mCoffSectionsOffset[Sym->st_shndx];
> > > +    *(UINT64 *)Targ = Sym->st_value + Rel->r_addend;
> > >       break;
> > >     case R_RISCV_HI20:
> > > @@ -533,6 +535,18 @@ WriteSectionRiscV64 (
> > >       mRiscVPass1SymSecIndex = 0;
> > >       break;
> > > +  case R_RISCV_GOT_HI20:
> > > +    Value = (Sym->st_value - Rel->r_offset);
> > > +    mRiscVPass1Offset = RV_X(Value, 0, 12);
> > > +    Value = RV_X(Value, 12, 20);
> > > +    *(UINT32 *)Targ = (Value << 12) | (RV_X(*(UINT32*)Targ, 0, 12));
> > > +
> > > +    mRiscVPass1Targ = Targ;
> > > +    mRiscVPass1Sym = SymShdr;
> > > +    mRiscVPass1SymSecIndex = Sym->st_shndx;
> > > +    mRiscVPass1GotFixup = 1;
> > > +    break;
> > > +
> > >     case R_RISCV_PCREL_HI20:
> > >       mRiscVPass1Targ = Targ;
> > >       mRiscVPass1Sym = SymShdr;
> > > @@ -545,11 +559,17 @@ WriteSectionRiscV64 (
> > >       if (mRiscVPass1Targ != NULL && mRiscVPass1Sym != NULL && mRiscVPass1SymSecIndex != 0) {
> > >         int i;
> > >         Value2 = (UINT32)(RV_X(*(UINT32 *)mRiscVPass1Targ, 12, 20));
> > > -      Value = (UINT32)(RV_X(*(UINT32 *)Targ, 20, 12));
> > > -      if(Value & (RISCV_IMM_REACH/2)) {
> > > -        Value |= ~(RISCV_IMM_REACH-1);
> > > +
> > > +      if(mRiscVPass1GotFixup) {
> > > +        Value = (UINT32)(mRiscVPass1Offset);
> > > +      } else {
> > > +        Value = (UINT32)(RV_X(*(UINT32 *)Targ, 20, 12));
> > > +        if(Value & (RISCV_IMM_REACH/2)) {
> > > +          Value |= ~(RISCV_IMM_REACH-1);
> > > +        }
> > >         }
> > >         Value = Value - (UINT32)mRiscVPass1Sym->sh_addr + mCoffSectionsOffset[mRiscVPass1SymSecIndex];
> > > +
> > >         if(-2048 > (INT32)Value) {
> > >           i = (((INT32)Value * -1) / 4096);
> > >           Value2 -= i;
> > > @@ -569,12 +589,21 @@ WriteSectionRiscV64 (
> > >           }
> > >         }
> > > -      *(UINT32 *)Targ = (RV_X(Value, 0, 12) << 20) | (RV_X(*(UINT32*)Targ, 0, 20));
> > > +      if(mRiscVPass1GotFixup) {
> > > +        *(UINT32 *)Targ = (RV_X((UINT32)Value, 0, 12) << 20)
> > > +                            | (RV_X(*(UINT32*)Targ, 0, 20));
> > > +        /* Convert LD instruction to ADDI */
> > > +        *(UINT32 *)Targ = ((*(UINT32 *)Targ & ~0x707f) | 0x13);
> > > +      } else {
> > > +        *(UINT32 *)Targ = (RV_X(Value, 0, 12) << 20) | (RV_X(*(UINT32*)Targ, 0, 20));
> > > +      }
> > >         *(UINT32 *)mRiscVPass1Targ = (RV_X(Value2, 0, 20)<<12) | (RV_X(*(UINT32 *)mRiscVPass1Targ, 0, 12));
> > >       }
> > >       mRiscVPass1Sym = NULL;
> > >       mRiscVPass1Targ = NULL;
> > >       mRiscVPass1SymSecIndex = 0;
> > > +    mRiscVPass1Offset = 0;
> > > +    mRiscVPass1GotFixup = 0;
> > >       break;
> > >     case R_RISCV_ADD64:
> > > @@ -586,6 +615,7 @@ WriteSectionRiscV64 (
> > >     case R_RISCV_GPREL_I:
> > >     case R_RISCV_GPREL_S:
> > >     case R_RISCV_CALL:
> > > +  case R_RISCV_CALL_PLT:
> > >     case R_RISCV_RVC_BRANCH:
> > >     case R_RISCV_RVC_JUMP:
> > >     case R_RISCV_RELAX:
> > > @@ -1528,6 +1558,7 @@ WriteRelocations64 (
> > >               case R_RISCV_GPREL_I:
> > >               case R_RISCV_GPREL_S:
> > >               case R_RISCV_CALL:
> > > +            case R_RISCV_CALL_PLT:
> > >               case R_RISCV_RVC_BRANCH:
> > >               case R_RISCV_RVC_JUMP:
> > >               case R_RISCV_RELAX:
> > > @@ -1537,6 +1568,7 @@ WriteRelocations64 (
> > >               case R_RISCV_SET16:
> > >               case R_RISCV_SET32:
> > >               case R_RISCV_PCREL_HI20:
> > > +            case R_RISCV_GOT_HI20:
> > >               case R_RISCV_PCREL_LO12_I:
> > >                 break;
> > > -- 
> > > 2.25.1
> > > 
> > 
>