Re: [PATCH] BaseTools GenFw: Add support for R_RISCV_PCREL_LO12_S relocation


Pete Batard
 

Hi Sunil,

Thanks a lot for this patch.

I confirm that it fixes the issue I raised in BZ3459.

If anyone is interested, you can find builds of the RISC-V NTFS driver, where this patch has been applied, in the artefacts of https://github.com/pbatard/ntfs-3g/actions/runs/1022633741.

With this:

On 2021.07.10 07:31, Sunil V L wrote:
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3459
This patch adds support for R_RISCV_PCREL_LO12_S relocation type.
The logic is same as existing R_RISCV_PCREL_LO12_I relocation
except the difference between load vs store instruction formats.
Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Yuwei Chen <yuwei.chen@intel.com>
Cc: Pete Batard <pete@akeo.ie>
Cc: Abner Chang <abner.chang@hpe.com>
Cc: Daniel Schaefer <daniel.schaefer@hpe.com>
---
BaseTools/Source/C/GenFw/Elf64Convert.c | 55 +++++++++++++++++++++++++
1 file changed, 55 insertions(+)
diff --git a/BaseTools/Source/C/GenFw/Elf64Convert.c b/BaseTools/Source/C/GenFw/Elf64Convert.c
index 3d7e20aaff..0bb3ead228 100644
--- a/BaseTools/Source/C/GenFw/Elf64Convert.c
+++ b/BaseTools/Source/C/GenFw/Elf64Convert.c
@@ -557,6 +557,60 @@ WriteSectionRiscV64 (
Value = (UINT32)(RV_X(*(UINT32 *)mRiscVPass1Targ, 12, 20));
break;
+ case R_RISCV_PCREL_LO12_S:
+ if (mRiscVPass1Targ != NULL && mRiscVPass1Sym != NULL && mRiscVPass1SymSecIndex != 0) {
+ int i;
+ Value2 = (UINT32)(RV_X(*(UINT32 *)mRiscVPass1Targ, 12, 20));
+
+ Value = ((UINT32)(RV_X(*(UINT32 *)Targ, 25, 7)) << 5);
+ Value = (Value | (UINT32)(RV_X(*(UINT32 *)Targ, 7, 5)));
+
+ 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;
+ Value += 4096 * i;
+ if(-2048 > (INT32)Value) {
+ Value2 -= 1;
+ Value += 4096;
+ }
+ }
+ else if( 2047 < (INT32)Value) {
+ i = (Value / 4096);
+ Value2 += i;
+ Value -= 4096 * i;
+ if(2047 < (INT32)Value) {
+ Value2 += 1;
+ Value -= 4096;
+ }
+ }
+
+ // Update the IMM of SD instruction
+ //
+ // |31 25|24 20|19 15|14 12 |11 7|6 0|
+ // |-------------------------------------------|-------|
+ // |imm[11:5] | rs2 | rs1 | funct3 |imm[4:0] | opcode|
+ // ---------------------------------------------------
+
+ // First Zero out current IMM
+ *(UINT32 *)Targ &= ~0xfe000f80;
+
+ // Update with new IMM
+ *(UINT32 *)Targ |= (RV_X(Value, 5, 7) << 25);
+ *(UINT32 *)Targ |= (RV_X(Value, 0, 5) << 7);
+
+ // Update previous instruction
+ *(UINT32 *)mRiscVPass1Targ = (RV_X(Value2, 0, 20)<<12) | (RV_X(*(UINT32 *)mRiscVPass1Targ, 0, 12));
+ }
+ mRiscVPass1Sym = NULL;
+ mRiscVPass1Targ = NULL;
+ mRiscVPass1SymSecIndex = 0;
+ break;
+
case R_RISCV_PCREL_LO12_I:
if (mRiscVPass1Targ != NULL && mRiscVPass1Sym != NULL && mRiscVPass1SymSecIndex != 0) {
int i;
@@ -1587,6 +1641,7 @@ WriteRelocations64 (
case R_RISCV_PCREL_HI20:
case R_RISCV_GOT_HI20:
case R_RISCV_PCREL_LO12_I:
+ case R_RISCV_PCREL_LO12_S:
break;
default:
Tested-by: Pete Batard <pete@akeo.ie>

Join devel@edk2.groups.io to automatically receive all group messages.