[PATCH v4 07/10] RISC-V: Add awareness for RISC-V reloations

[Alexander Graf <agraf@suse.de>]

This patch adds awareness of RISC-V relocations throughout the grub tools
as well as dynamic linkage and elf->PE relocation conversion support.

Signed-off-by: Alexander Graf <agraf@suse.de>

---

v2 -> v3:

  - Fix riscv32 target

v3 -> v4:

  - Change copyright from 2013 to 2018
  - Add spec reference
---
 grub-core/kern/dl.c         |   6 +-
 grub-core/kern/riscv/dl.c   | 340 ++++++++++++++++++++++++++++++++++++++++++++
 include/grub/dl.h           |   6 +-
 util/grub-mkimagexx.c       | 268 ++++++++++++++++++++++++++++++++++
 util/grub-module-verifier.c |  56 ++++++++
 5 files changed, 671 insertions(+), 5 deletions(-)
 create mode 100644 grub-core/kern/riscv/dl.c

diff --git a/grub-core/kern/dl.c b/grub-core/kern/dl.c
index f8d58f029..48eb5e7b6 100644
--- a/grub-core/kern/dl.c
+++ b/grub-core/kern/dl.c
@@ -225,7 +225,7 @@ grub_dl_load_segments (grub_dl_t mod, const Elf_Ehdr *e)
   unsigned i;
   const Elf_Shdr *s;
   grub_size_t tsize = 0, talign = 1;
-#if !defined (__i386__) && !defined (__x86_64__)
+#if !defined (__i386__) && !defined (__x86_64__) && !defined(__riscv)
   grub_size_t tramp;
   grub_size_t got;
   grub_err_t err;
@@ -241,7 +241,7 @@ grub_dl_load_segments (grub_dl_t mod, const Elf_Ehdr *e)
 	talign = s->sh_addralign;
     }
 
-#if !defined (__i386__) && !defined (__x86_64__)
+#if !defined (__i386__) && !defined (__x86_64__) && !defined(__riscv)
   err = grub_arch_dl_get_tramp_got_size (e, &tramp, &got);
   if (err)
     return err;
@@ -304,7 +304,7 @@ grub_dl_load_segments (grub_dl_t mod, const Elf_Ehdr *e)
 	  mod->segment = seg;
 	}
     }
-#if !defined (__i386__) && !defined (__x86_64__)
+#if !defined (__i386__) && !defined (__x86_64__) && !defined(__riscv)
   ptr = (char *) ALIGN_UP ((grub_addr_t) ptr, GRUB_ARCH_DL_TRAMP_ALIGN);
   mod->tramp = ptr;
   mod->trampptr = ptr;
diff --git a/grub-core/kern/riscv/dl.c b/grub-core/kern/riscv/dl.c
new file mode 100644
index 000000000..6fb8385ef
--- /dev/null
+++ b/grub-core/kern/riscv/dl.c
@@ -0,0 +1,340 @@
+/* dl.c - arch-dependent part of loadable module support */
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2018  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/dl.h>
+#include <grub/elf.h>
+#include <grub/misc.h>
+#include <grub/err.h>
+#include <grub/mm.h>
+#include <grub/i18n.h>
+
+/*
+ * Instructions and instruction encoding are documented in the RISC-V
+ * specification. This file is based on version 2.2:
+ *
+ * https://github.com/riscv/riscv-isa-manual/blob/master/release/riscv-spec-v2.2.pdf
+ */
+#define LDR 0x58000050
+#define BR 0xd61f0200
+
+/*
+ * Check if EHDR is a valid ELF header.
+ */
+grub_err_t
+grub_arch_dl_check_header (void *ehdr)
+{
+  Elf_Ehdr *e = ehdr;
+
+  /* Check the magic numbers.  */
+  if (e->e_ident[EI_DATA] != ELFDATA2LSB || e->e_machine != EM_RISCV)
+    return grub_error (GRUB_ERR_BAD_OS,
+		       N_("invalid arch-dependent ELF magic"));
+
+  return GRUB_ERR_NONE;
+}
+
+#pragma GCC diagnostic ignored "-Wcast-align"
+
+/* Relocate symbols. */
+grub_err_t
+grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr,
+			       Elf_Shdr *s, grub_dl_segment_t seg)
+{
+  Elf_Rel *rel, *max;
+
+  for (rel = (Elf_Rel *) ((char *) ehdr + s->sh_offset),
+	 max = (Elf_Rel *) ((char *) rel + s->sh_size);
+       rel < max;
+       rel = (Elf_Rel *) ((char *) rel + s->sh_entsize))
+    {
+      Elf_Sym *sym;
+      void *place;
+      grub_size_t sym_addr;
+
+      if (rel->r_offset >= seg->size)
+	return grub_error (GRUB_ERR_BAD_MODULE,
+			   "reloc offset is out of the segment");
+
+      sym = (Elf_Sym *) ((char *) mod->symtab
+			 + mod->symsize * ELF_R_SYM (rel->r_info));
+
+      sym_addr = sym->st_value;
+      if (s->sh_type == SHT_RELA)
+	sym_addr += ((Elf_Rela *) rel)->r_addend;
+
+      place = (void *) ((grub_addr_t) seg->addr + rel->r_offset);
+
+      switch (ELF_R_TYPE (rel->r_info))
+	{
+	case R_RISCV_32:
+	  {
+	    grub_uint32_t *abs_place = place;
+
+	    grub_dprintf ("dl", "  reloc_abs32 %p => 0x%016llx\n",
+			  place, (unsigned long long) sym_addr);
+
+	    *abs_place = (grub_uint32_t) sym_addr;
+	  }
+	  break;
+	case R_RISCV_64:
+	  {
+	    grub_size_t *abs_place = place;
+
+	    grub_dprintf ("dl", "  reloc_abs64 %p => 0x%016llx\n",
+			  place, (unsigned long long) sym_addr);
+
+	    *abs_place = (grub_size_t) sym_addr;
+	  }
+	  break;
+
+	case R_RISCV_ADD8:
+	  {
+	    grub_uint8_t *abs_place = place;
+
+	    *abs_place += (grub_uint8_t) sym_addr;
+	  }
+	  break;
+	case R_RISCV_ADD16:
+	  {
+	    grub_uint16_t *abs_place = place;
+
+	    *abs_place += (grub_uint16_t) sym_addr;
+	  }
+	  break;
+	case R_RISCV_ADD32:
+	  {
+	    grub_uint32_t *abs_place = place;
+
+	    *abs_place += (grub_uint32_t) sym_addr;
+	  }
+	  break;
+	case R_RISCV_ADD64:
+	  {
+	    grub_size_t *abs_place = place;
+
+	    *abs_place += (grub_size_t) sym_addr;
+	  }
+	  break;
+
+	case R_RISCV_SUB8:
+	  {
+	    grub_uint8_t *abs_place = place;
+
+	    *abs_place -= (grub_uint8_t) sym_addr;
+	  }
+	  break;
+	case R_RISCV_SUB16:
+	  {
+	    grub_uint16_t *abs_place = place;
+
+	    *abs_place -= (grub_uint16_t) sym_addr;
+	  }
+	  break;
+	case R_RISCV_SUB32:
+	  {
+	    grub_uint32_t *abs_place = place;
+
+	    *abs_place -= (grub_uint32_t) sym_addr;
+	  }
+	  break;
+	case R_RISCV_SUB64:
+	  {
+	    grub_size_t *abs_place = place;
+
+	    *abs_place -= (grub_size_t) sym_addr;
+	  }
+	  break;
+
+	case R_RISCV_BRANCH:
+	  {
+	    grub_uint32_t *abs_place = place;
+	    grub_ssize_t off = sym_addr - (grub_addr_t) place;
+	    grub_uint32_t imm12 = (off & 0x1000) << (31 - 12);
+	    grub_uint32_t imm11 = (off & 0x800) >> (11 - 7);
+	    grub_uint32_t imm10_5 = (off & 0x7e0) << (30 - 10);
+	    grub_uint32_t imm4_1 = (off & 0x1e) << (11 - 4);
+	    *abs_place = (*abs_place & 0x1fff07f)
+			 | imm12 | imm11 | imm10_5 | imm4_1;
+	  }
+	  break;
+
+	case R_RISCV_JAL:
+	  {
+	    grub_uint32_t *abs_place = place;
+	    grub_ssize_t off = sym_addr - (grub_addr_t) place;
+	    grub_uint32_t imm20 = (off & 0x100000) << (31 - 20);
+	    grub_uint32_t imm19_12 = (off & 0xff000);
+	    grub_uint32_t imm11 = (off & 0x800) << (20 - 11);
+	    grub_uint32_t imm10_1 = (off & 0x7fe) << (30 - 10);
+	    *abs_place = (*abs_place & 0xfff)
+			 | imm20 | imm19_12 | imm11 | imm10_1;
+	  }
+	  break;
+
+	case R_RISCV_CALL:
+	  {
+	    grub_uint32_t *abs_place = place;
+	    grub_ssize_t off = sym_addr - (grub_addr_t) place;
+	    grub_uint32_t hi20, lo12;
+
+	    if (off != (grub_int32_t) off)
+	      return grub_error (GRUB_ERR_BAD_MODULE, "relocation overflow");
+
+	    hi20 = (off + 0x800) & 0xfffff000;
+	    lo12 = (off - hi20) & 0xfff;
+	    abs_place[0] = (abs_place[0] & 0xfff) | hi20;
+	    abs_place[1] = (abs_place[1] & 0xfffff) | (lo12 << 20);
+	  }
+	  break;
+
+	case R_RISCV_RVC_BRANCH:
+	  {
+	    grub_uint16_t *abs_place = place;
+	    grub_ssize_t off = sym_addr - (grub_addr_t) place;
+	    grub_uint16_t imm8 = (off & 0x100) << (12 - 8);
+	    grub_uint16_t imm7_6 = (off & 0xc0) >> (6 - 5);
+	    grub_uint16_t imm5 = (off & 0x20) >> (5 - 2);
+	    grub_uint16_t imm4_3 = (off & 0x18) << (12 - 5);
+	    grub_uint16_t imm2_1 = (off & 0x6) << (12 - 10);
+	    *abs_place = (*abs_place & 0xe383)
+			 | imm8 | imm7_6 | imm5 | imm4_3 | imm2_1;
+	  }
+	  break;
+
+	case R_RISCV_RVC_JUMP:
+	  {
+	    grub_uint16_t *abs_place = place;
+	    grub_ssize_t off = sym_addr - (grub_addr_t) place;
+	    grub_uint16_t imm11 = (off & 0x800) << (12 - 11);
+	    grub_uint16_t imm10 = (off & 0x400) >> (10 - 8);
+	    grub_uint16_t imm9_8 = (off & 0x300) << (12 - 11);
+	    grub_uint16_t imm7 = (off & 0x80) >> (7 - 6);
+	    grub_uint16_t imm6 = (off & 0x40) << (12 - 11);
+	    grub_uint16_t imm5 = (off & 0x20) >> (5 - 2);
+	    grub_uint16_t imm4 = (off & 0x10) << (12 - 5);
+	    grub_uint16_t imm3_1 = (off & 0xe) << (12 - 10);
+	    *abs_place = ((*abs_place & 0xe003)
+			  | imm11 | imm10 | imm9_8 | imm7 | imm6
+			  | imm5 | imm4 | imm3_1);
+	  }
+	  break;
+
+	case R_RISCV_PCREL_HI20:
+	  {
+	    grub_uint32_t *abs_place = place;
+	    grub_ssize_t off = sym_addr - (grub_addr_t) place;
+	    grub_int32_t hi20;
+
+	    if (off != (grub_int32_t)off)
+	      return grub_error (GRUB_ERR_BAD_MODULE, "relocation overflow");
+
+	    hi20 = (off + 0x800) & 0xfffff000;
+	    *abs_place = (*abs_place & 0xfff) | hi20;
+	  }
+	break;
+
+	case R_RISCV_PCREL_LO12_I:
+	case R_RISCV_PCREL_LO12_S:
+	  {
+	    grub_uint32_t *t32 = place;
+	    Elf_Rela *rel2;
+	    /* Search backwards for matching HI20 reloc.  */
+	    for (rel2 = (Elf_Rela *) ((char *) rel - s->sh_entsize);
+		    (unsigned long)rel2 >= ((unsigned long)ehdr + s->sh_offset);
+		    rel2 = (Elf_Rela *) ((char *) rel2 - s->sh_entsize))
+	      {
+		Elf_Addr rel2_info;
+		Elf_Addr rel2_offset;
+		Elf_Addr rel2_sym_addr;
+		Elf_Addr rel2_loc;
+		grub_ssize_t rel2_off;
+		grub_ssize_t off;
+		Elf_Sym *sym2;
+
+		rel2_offset = rel2->r_offset;
+		rel2_info = rel2->r_info;
+		rel2_loc = (grub_addr_t) seg->addr + rel2_offset;
+
+		if (ELF_R_TYPE (rel2_info) == R_RISCV_PCREL_HI20
+		    && rel2_loc == sym_addr)
+		  {
+		    sym2 = (Elf_Sym *) ((char *) mod->symtab
+				+ mod->symsize * ELF_R_SYM (rel2->r_info));
+		    rel2_sym_addr = sym2->st_value;
+		    if (s->sh_type == SHT_RELA)
+		      rel2_sym_addr += ((Elf_Rela *) rel2)->r_addend;
+
+		    rel2_off = rel2_sym_addr - rel2_loc;
+		    off = rel2_off - ((rel2_off + 0x800) & 0xfffff000);
+
+		    if (ELF_R_TYPE (rel->r_info) == R_RISCV_PCREL_LO12_I)
+		      *t32 = (*t32 & 0xfffff) | (off & 0xfff) << 20;
+		    else
+		      {
+			grub_uint32_t imm11_5 = (off & 0xfe0) << (31 - 11);
+			grub_uint32_t imm4_0 = (off & 0x1f) << (11 - 4);
+			*t32 = (*t32 & 0x1fff07f) | imm11_5 | imm4_0;
+		      }
+		    break;
+		  }
+	      }
+	    if ((unsigned long)rel2 < ((unsigned long)ehdr + s->sh_offset))
+	      return grub_error (GRUB_ERR_BAD_MODULE, "cannot find matching HI20 relocation");
+	  }
+	  break;
+
+	case R_RISCV_HI20:
+	  {
+	    grub_uint32_t *abs_place = place;
+	    *abs_place = (*abs_place & 0xfff) |
+			 (((grub_int32_t) sym_addr + 0x800) & 0xfffff000);
+	  }
+	  break;
+
+	case R_RISCV_LO12_I:
+	  {
+	    grub_uint32_t *abs_place = place;
+	    grub_int32_t lo12 = (grub_int32_t) sym_addr -
+				(((grub_int32_t) sym_addr + 0x800) & 0xfffff000);
+	    *abs_place = (*abs_place & 0xfffff) | ((lo12 & 0xfff) << 20);
+	  }
+	  break;
+
+	case R_RISCV_LO12_S:
+	  {
+	    grub_uint32_t *abs_place = place;
+	    grub_int32_t lo12 = (grub_int32_t) sym_addr -
+				(((grub_int32_t) sym_addr + 0x800) & 0xfffff000);
+	    grub_uint32_t imm11_5 = (lo12 & 0xfe0) << (31 - 11);
+	    grub_uint32_t imm4_0 = (lo12 & 0x1f) << (11 - 4);
+	    *abs_place = (*abs_place & 0x1fff07f) | imm11_5 | imm4_0;
+	  }
+	  break;
+
+	case R_RISCV_RELAX:
+	  break;
+	default:
+	  return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
+			     N_("relocation 0x%x is not implemented yet"),
+			     ELF_R_TYPE (rel->r_info));
+	}
+    }
+
+  return GRUB_ERR_NONE;
+}
diff --git a/include/grub/dl.h b/include/grub/dl.h
index fee27a14c..f03c03561 100644
--- a/include/grub/dl.h
+++ b/include/grub/dl.h
@@ -292,12 +292,14 @@ grub_arch_dl_get_tramp_got_size (const void *ehdr, grub_size_t *tramp,
 				 grub_size_t *got);
 #endif
 
-#if defined (__powerpc__) || defined (__mips__) || defined (__arm__)
+#if defined (__powerpc__) || defined (__mips__) || defined (__arm__) || \
+    (defined(__riscv) && (__riscv_xlen == 32))
 #define GRUB_ARCH_DL_TRAMP_ALIGN 4
 #define GRUB_ARCH_DL_GOT_ALIGN 4
 #endif
 
-#if defined (__aarch64__) || defined (__sparc__)
+#if defined (__aarch64__) || defined (__sparc__) || \
+    (defined(__riscv) && (__riscv_xlen == 64))
 #define GRUB_ARCH_DL_TRAMP_ALIGN 8
 #define GRUB_ARCH_DL_GOT_ALIGN 8
 #endif
diff --git a/util/grub-mkimagexx.c b/util/grub-mkimagexx.c
index a483c674c..a94d03540 100644
--- a/util/grub-mkimagexx.c
+++ b/util/grub-mkimagexx.c
@@ -1188,6 +1188,205 @@ SUFFIX (relocate_addrs) (Elf_Ehdr *e, struct section_metadata *smd,
 		 break;
 	       }
 #endif /* MKIMAGE_ELF32 */
+	     case EM_RISCV:
+	       {
+		 grub_uint64_t *t64 = (grub_uint64_t *) target;
+		 grub_uint32_t *t32 = (grub_uint32_t *) target;
+		 grub_uint16_t *t16 = (grub_uint16_t *) target;
+		 grub_uint8_t *t8 = (grub_uint8_t *) target;
+		 grub_int64_t off = (long)sym_addr - target_section_addr - offset
+				    - image_target->vaddr_offset;
+
+		 sym_addr += addend;
+
+		 switch (ELF_R_TYPE (info))
+		   {
+		   case R_RISCV_ADD8:
+		     {
+		       *t8 = *t8 + sym_addr;
+		     }
+		     break;
+		   case R_RISCV_ADD16:
+		     {
+		       *t16 = grub_host_to_target16 (grub_target_to_host16 (*t16) + sym_addr);
+		     }
+		     break;
+		   case R_RISCV_32:
+		   case R_RISCV_ADD32:
+		     {
+		       *t32 = grub_host_to_target32 (grub_target_to_host32 (*t32) + sym_addr);
+		     }
+		     break;
+		   case R_RISCV_64:
+		   case R_RISCV_ADD64:
+		     {
+		       *t64 = grub_host_to_target64 (grub_target_to_host64 (*t64) + sym_addr);
+		     }
+		     break;
+
+		   case R_RISCV_SUB8:
+		     {
+		       *t8 = sym_addr - *t8;
+		     }
+		     break;
+		   case R_RISCV_SUB16:
+		     {
+		       *t16 = grub_host_to_target16 (grub_target_to_host16 (*t16) - sym_addr);
+		     }
+		     break;
+		   case R_RISCV_SUB32:
+		     {
+		       *t32 = grub_host_to_target32 (grub_target_to_host32 (*t32) - sym_addr);
+		     }
+		     break;
+		   case R_RISCV_SUB64:
+		     {
+		       *t64 = grub_host_to_target64 (grub_target_to_host64 (*t64) - sym_addr);
+		     }
+		     break;
+		   case R_RISCV_BRANCH:
+		     {
+		       grub_uint32_t imm12 = (off & 0x1000) << (31 - 12);
+		       grub_uint32_t imm11 = (off & 0x800) >> (11 - 7);
+		       grub_uint32_t imm10_5 = (off & 0x7e0) << (30 - 10);
+		       grub_uint32_t imm4_1 = (off & 0x1e) << (11 - 4);
+		       *t32 = grub_host_to_target32 ((grub_target_to_host32 (*t32) & 0x1fff07f)
+						     | imm12 | imm11 | imm10_5 | imm4_1);
+		     }
+		     break;
+		   case R_RISCV_JAL:
+		     {
+		       grub_uint32_t imm20 = (off & 0x100000) << (31 - 20);
+		       grub_uint32_t imm19_12 = (off & 0xff000);
+		       grub_uint32_t imm11 = (off & 0x800) << (20 - 11);
+		       grub_uint32_t imm10_1 = (off & 0x7fe) << (30 - 10);
+		       *t32 = grub_host_to_target32 ((grub_target_to_host32 (*t32) & 0xfff)
+						     | imm20 | imm19_12 | imm11 | imm10_1);
+		     }
+		     break;
+		   case R_RISCV_CALL:
+		     {
+		       grub_uint32_t hi20, lo12;
+
+		       if (off != (grub_int32_t)off)
+			 grub_util_error ("target %lx not reachable from pc=%lx", (long)sym_addr, (long)target);
+
+		       hi20 = (off + 0x800) & 0xfffff000;
+		       lo12 = (off - hi20) & 0xfff;
+		       t32[0] = grub_host_to_target32 ((grub_target_to_host32 (t32[0]) & 0xfff) | hi20);
+		       t32[1] = grub_host_to_target32 ((grub_target_to_host32 (t32[1]) & 0xfffff) | (lo12 << 20));
+		     }
+		     break;
+		   case R_RISCV_RVC_BRANCH:
+		     {
+		       grub_uint16_t imm8 = (off & 0x100) << (12 - 8);
+		       grub_uint16_t imm7_6 = (off & 0xc0) >> (6 - 5);
+		       grub_uint16_t imm5 = (off & 0x20) >> (5 - 2);
+		       grub_uint16_t imm4_3 = (off & 0x18) << (12 - 5);
+		       grub_uint16_t imm2_1 = (off & 0x6) << (12 - 10);
+		       *t16 = grub_host_to_target16 ((grub_target_to_host16 (*t16) & 0xe383)
+						     | imm8 | imm7_6 | imm5 | imm4_3 | imm2_1);
+		     }
+		     break;
+		   case R_RISCV_RVC_JUMP:
+		     {
+		       grub_uint16_t imm11 = (off & 0x800) << (12 - 11);
+		       grub_uint16_t imm10 = (off & 0x400) >> (10 - 8);
+		       grub_uint16_t imm9_8 = (off & 0x300) << (12 - 11);
+		       grub_uint16_t imm7 = (off & 0x80) >> (7 - 6);
+		       grub_uint16_t imm6 = (off & 0x40) << (12 - 11);
+		       grub_uint16_t imm5 = (off & 0x20) >> (5 - 2);
+		       grub_uint16_t imm4 = (off & 0x10) << (12 - 5);
+		       grub_uint16_t imm3_1 = (off & 0xe) << (12 - 10);
+		       *t16 = grub_host_to_target16 ((grub_target_to_host16 (*t16) & 0xe003)
+						     | imm11 | imm10 | imm9_8 | imm7 | imm6
+						     | imm5 | imm4 | imm3_1);
+		     }
+		     break;
+		   case R_RISCV_PCREL_HI20:
+		     {
+		       grub_int32_t hi20;
+
+		       if (off != (grub_int32_t)off)
+			 grub_util_error ("target %lx not reachable from pc=%lx", (long)sym_addr, (long)target);
+
+		       hi20 = (off + 0x800) & 0xfffff000;
+		       *t32 = grub_host_to_target32 ((grub_target_to_host32 (*t32) & 0xfff) | hi20);
+		     }
+		     break;
+		   case R_RISCV_PCREL_LO12_I:
+		   case R_RISCV_PCREL_LO12_S:
+		     {
+		       Elf_Rela *rel2;
+		       Elf_Word k;
+		       /* Search backwards for matching HI20 reloc.  */
+		       for (k = j, rel2 = (Elf_Rela *) ((char *) r - r_size);
+			    k > 0;
+			    k--, rel2 = (Elf_Rela *) ((char *) rel2 - r_size))
+			 {
+			   Elf_Addr rel2_info;
+			   Elf_Addr rel2_offset;
+			   Elf_Addr rel2_sym_addr;
+			   Elf_Addr rel2_addend;
+			   Elf_Addr rel2_loc;
+			   grub_int64_t rel2_off;
+
+			   rel2_offset = grub_target_to_host (rel2->r_offset);
+			   rel2_info = grub_target_to_host (rel2->r_info);
+			   rel2_loc = target_section_addr + rel2_offset + image_target->vaddr_offset;
+
+			   if (ELF_R_TYPE (rel2_info) == R_RISCV_PCREL_HI20
+			       && rel2_loc == sym_addr)
+			     {
+			       rel2_sym_addr = SUFFIX (get_symbol_address)
+				 (e, smd->symtab, ELF_R_SYM (rel2_info),
+				  image_target);
+			       rel2_addend = (s->sh_type == grub_target_to_host32 (SHT_RELA)) ?
+				 grub_target_to_host (rel2->r_addend) : 0;
+			       rel2_off = rel2_sym_addr + rel2_addend - rel2_loc;
+			       off = rel2_off - ((rel2_off + 0x800) & 0xfffff000);
+
+			       if (ELF_R_TYPE (info) == R_RISCV_PCREL_LO12_I)
+				 *t32 = grub_host_to_target32 ((grub_target_to_host32 (*t32) & 0xfffff) | (off & 0xfff) << 20);
+			       else
+				 {
+				   grub_uint32_t imm11_5 = (off & 0xfe0) << (31 - 11);
+				   grub_uint32_t imm4_0 = (off & 0x1f) << (11 - 4);
+				   *t32 = grub_host_to_target32 ((grub_target_to_host32 (*t32) & 0x1fff07f) | imm11_5 | imm4_0);
+				 }
+			       break;
+			     }
+			 }
+		       if (k == 0)
+			 grub_util_error ("cannot find matching HI20 relocation");
+		     }
+		     break;
+		   case R_RISCV_HI20:
+		     *t32 = grub_host_to_target32 ((grub_target_to_host32 (*t32) & 0xfff) | (((grub_int32_t) sym_addr + 0x800) & 0xfffff000));
+		     break;
+		   case R_RISCV_LO12_I:
+		     {
+		       grub_int32_t lo12 = (grub_int32_t) sym_addr - (((grub_int32_t) sym_addr + 0x800) & 0xfffff000);
+		       *t32 = grub_host_to_target32 ((grub_target_to_host32 (*t32) & 0xfffff) | ((lo12 & 0xfff) << 20));
+		     }
+		     break;
+		   case R_RISCV_LO12_S:
+		     {
+		       grub_int32_t lo12 = (grub_int32_t) sym_addr - (((grub_int32_t) sym_addr + 0x800) & 0xfffff000);
+		       grub_uint32_t imm11_5 = (lo12 & 0xfe0) << (31 - 11);
+		       grub_uint32_t imm4_0 = (lo12 & 0x1f) << (11 - 4);
+		       *t32 = grub_host_to_target32 ((grub_target_to_host32 (*t32) & 0x1fff07f) | imm11_5 | imm4_0);
+		     }
+		     break;
+		   case R_RISCV_RELAX:
+		     break;
+		   default:
+		     grub_util_error (_("relocation 0x%x is not implemented yet"),
+				      (unsigned int) ELF_R_TYPE (info));
+		     break;
+		   }
+	       break;
+	       }
 	     default:
 	       grub_util_error ("unknown architecture type %d",
 				image_target->elf_target);
@@ -1472,6 +1671,75 @@ translate_relocation_pe (struct translate_context *ctx,
 	}
       break;
 #endif /* defined(MKIMAGE_ELF32) */
+    case EM_RISCV:
+      switch (ELF_R_TYPE (info))
+	{
+	case R_RISCV_32:
+	  {
+	    ctx->current_address
+	      = add_fixup_entry (&ctx->lst,
+				 GRUB_PE32_REL_BASED_HIGHLOW,
+				 addr, 0, ctx->current_address,
+				 image_target);
+	  }
+	  break;
+	case R_RISCV_64:
+	  {
+	    ctx->current_address
+	      = add_fixup_entry (&ctx->lst,
+				 GRUB_PE32_REL_BASED_DIR64,
+				 addr, 0, ctx->current_address,
+				 image_target);
+	  }
+	  break;
+	  /* Relative relocations do not require fixup entries. */
+	case R_RISCV_BRANCH:
+	case R_RISCV_JAL:
+	case R_RISCV_CALL:
+	case R_RISCV_PCREL_HI20:
+	case R_RISCV_PCREL_LO12_I:
+	case R_RISCV_PCREL_LO12_S:
+	case R_RISCV_RVC_BRANCH:
+	case R_RISCV_RVC_JUMP:
+	case R_RISCV_ADD32:
+	case R_RISCV_SUB32:
+	  grub_util_info ("  %s:  not adding fixup: 0x%08x : 0x%08x", __FUNCTION__, (unsigned int) addr, (unsigned int) ctx->current_address);
+	  break;
+	case R_RISCV_HI20:
+	  {
+	    ctx->current_address
+	      = add_fixup_entry (&ctx->lst,
+				 GRUB_PE32_REL_BASED_RISCV_HI20,
+				 addr, 0, ctx->current_address,
+				 image_target);
+	  }
+	  break;
+	case R_RISCV_LO12_I:
+	  {
+	    ctx->current_address
+	      = add_fixup_entry (&ctx->lst,
+				 GRUB_PE32_REL_BASED_RISCV_LOW12I,
+				 addr, 0, ctx->current_address,
+				 image_target);
+	  }
+	  break;
+	case R_RISCV_LO12_S:
+	  {
+	    ctx->current_address
+	      = add_fixup_entry (&ctx->lst,
+				 GRUB_PE32_REL_BASED_RISCV_LOW12S,
+				 addr, 0, ctx->current_address,
+				 image_target);
+	  }
+	  break;
+	case R_RISCV_RELAX:
+	  break;
+	default:
+	  grub_util_error (_("relocation 0x%x is not implemented yet"),
+			   (unsigned int) ELF_R_TYPE (info));
+	  break;
+	}
+      break;
     default:
       grub_util_error ("unknown machine type 0x%x", image_target->elf_target);
     }
diff --git a/util/grub-module-verifier.c b/util/grub-module-verifier.c
index 03ba1ab43..7a32b010c 100644
--- a/util/grub-module-verifier.c
+++ b/util/grub-module-verifier.c
@@ -117,6 +117,62 @@ struct grub_module_verifier_arch archs[] = {
       R_AARCH64_LDST64_ABS_LO12_NC,
       R_AARCH64_PREL32,
       -1
+    } },
+  { "riscv32", 4, 0, EM_RISCV, GRUB_MODULE_VERIFY_SUPPORTS_REL | GRUB_MODULE_VERIFY_SUPPORTS_RELA, (int[]){
+      R_RISCV_32,
+      R_RISCV_64,
+      R_RISCV_ADD8,
+      R_RISCV_ADD16,
+      R_RISCV_ADD32,
+      R_RISCV_ADD64,
+      R_RISCV_SUB8,
+      R_RISCV_SUB16,
+      R_RISCV_SUB32,
+      R_RISCV_SUB64,
+      R_RISCV_ALIGN,
+      R_RISCV_BRANCH,
+      R_RISCV_CALL,
+      R_RISCV_CALL_PLT,
+      R_RISCV_GOT_HI20,
+      R_RISCV_HI20,
+      R_RISCV_JAL,
+      R_RISCV_LO12_I,
+      R_RISCV_LO12_S,
+      R_RISCV_PCREL_HI20,
+      R_RISCV_PCREL_LO12_I,
+      R_RISCV_PCREL_LO12_S,
+      R_RISCV_RELAX,
+      R_RISCV_RVC_BRANCH,
+      R_RISCV_RVC_JUMP,
+      -1
+    } },
+  { "riscv64", 8, 0, EM_RISCV, GRUB_MODULE_VERIFY_SUPPORTS_REL | GRUB_MODULE_VERIFY_SUPPORTS_RELA, (int[]){
+      R_RISCV_32,
+      R_RISCV_64,
+      R_RISCV_ADD8,
+      R_RISCV_ADD16,
+      R_RISCV_ADD32,
+      R_RISCV_ADD64,
+      R_RISCV_SUB8,
+      R_RISCV_SUB16,
+      R_RISCV_SUB32,
+      R_RISCV_SUB64,
+      R_RISCV_ALIGN,
+      R_RISCV_BRANCH,
+      R_RISCV_CALL,
+      R_RISCV_CALL_PLT,
+      R_RISCV_GOT_HI20,
+      R_RISCV_HI20,
+      R_RISCV_JAL,
+      R_RISCV_LO12_I,
+      R_RISCV_LO12_S,
+      R_RISCV_PCREL_HI20,
+      R_RISCV_PCREL_LO12_I,
+      R_RISCV_PCREL_LO12_S,
+      R_RISCV_RELAX,
+      R_RISCV_RVC_BRANCH,
+      R_RISCV_RVC_JUMP,
+      -1
     }
   },
 };
-- 
2.12.3