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

["Pete Batard" <pete@akeo.ie>]

I agree that this is unlikely to be a consequence of the current patch.

I logged new BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3459

Regards,

/Pete

On 2021.06.17 05:44, Sunil V L wrote:
> 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
>>>>
>>> 
>>