Index: llvm/include/llvm/BinaryFormat/ELF.h
===================================================================
--- llvm/include/llvm/BinaryFormat/ELF.h
+++ llvm/include/llvm/BinaryFormat/ELF.h
@@ -912,6 +912,39 @@
 #include "ELFRelocs/CSKY.def"
 };
 
+// RL78 Specific e_flags.
+enum : unsigned {
+  // Functional unit.
+  EF_RL78_FU_EXIST = 0x01,
+  // Extension instructions#.
+  EF_RL78_EI_EXIST = 0x08,
+  // MAA mode
+  EF_RL78_MAA_0 = 0x40,
+  EF_RL78_MAA_1 = 0xc0,
+  // CPU.
+  EF_RL78_CPU_8BIT = 0x100,
+  EF_RL78_CPU_16BIT = 0x300,
+  // Size of double in bytes.
+  EF_RL78_DOUBLE_4 = 0x400,
+  EF_RL78_DOUBLE_8 = 0xc00,
+  // Default function pointer.
+  EF_RL78_TEXT_NEAR = 0x1000,
+  EF_RL78_TEXT_FAR = 0x3000,
+  // Default data pointer.
+  EF_RL78_DATA_NEAR = 0x4000,
+  EF_RL78_DATA_FAR = 0xc000,
+  // Default constant data pointer.
+  EF_RL78_RODATA_NEAR = 0x10000,
+  EF_RL78_RODATA_FAR = 0x30000,
+  // RL78 e_flags mask.
+  EF_RL78_MASK = 0x3FFFF
+};
+
+// ELF Relocation type for RL78.
+enum {
+#include "ELFRelocs/RL78.def"
+};
+
 // LoongArch Specific e_flags
 enum : unsigned {
   // Definitions from LoongArch ELF psABI v2.01.
Index: llvm/include/llvm/BinaryFormat/ELFRelocs/RL78.def
===================================================================
--- /dev/null
+++ llvm/include/llvm/BinaryFormat/ELFRelocs/RL78.def
@@ -0,0 +1,53 @@
+#ifndef ELF_RELOC
+#error "ELF_RELOC must be defined"
+#endif
+
+ELF_RELOC(R_RL78_NONE,        0x00)
+ELF_RELOC(R_RL78_DIR3U,       0x01)
+ELF_RELOC(R_RL78_DIR8U,       0x02)
+ELF_RELOC(R_RL78_DIR16U,      0x04)
+ELF_RELOC(R_RL78_DIR20U,      0x06)
+ELF_RELOC(R_RL78_DIR20U_16,   0x07)
+ELF_RELOC(R_RL78_DIR20UW_16,  0x08)
+ELF_RELOC(R_RL78_DIR32U,      0x09)
+ELF_RELOC(R_RL78_DIR8U_MIR,   0x0a)
+ELF_RELOC(R_RL78_DIR16U_MIR,  0x0b)
+ELF_RELOC(R_RL78_DIR16UW_MIR, 0x0c)
+ELF_RELOC(R_RL78_DIR8U_SAD,   0x0e)
+ELF_RELOC(R_RL78_DIR8UW_SAD,  0x0f)
+ELF_RELOC(R_RL78_DIR16U_RAM,  0x10)
+ELF_RELOC(R_RL78_DIR16UW_RAM, 0x11)
+ELF_RELOC(R_RL78_DIR8S_PCREL, 0x12)
+ELF_RELOC(R_RL78_DIR16S_PCREL,0x13)
+ELF_RELOC(R_RL78_DIR_CALLT,   0x14)
+ELF_RELOC(R_RL78_ABS3U,       0x31)
+ELF_RELOC(R_RL78_ABS8U,       0x32)
+ELF_RELOC(R_RL78_ABS8UW,      0x33)
+ELF_RELOC(R_RL78_ABS16U,      0x34)
+ELF_RELOC(R_RL78_ABS16UW,     0x35)
+ELF_RELOC(R_RL78_ABS20U,      0x36)
+ELF_RELOC(R_RL78_ABS20U_16,   0x37)
+ELF_RELOC(R_RL78_ABS20UW_16,  0x38)
+ELF_RELOC(R_RL78_ABS32U,      0x39)
+ELF_RELOC(R_RL78_ABS8S_PCREL, 0x42)
+ELF_RELOC(R_RL78_ABS16S_PCREL,0x43)
+ELF_RELOC(R_RL78_ABS_CALLT,   0x44)
+ELF_RELOC(R_RL78_REF,         0x70)
+ELF_RELOC(R_RL78_SYM,         0x80)
+ELF_RELOC(R_RL78_SYM_MIR,     0x81)
+ELF_RELOC(R_RL78_OPadd,       0x82)
+ELF_RELOC(R_RL78_OPsub,       0x83)
+ELF_RELOC(R_RL78_OPsctsize,   0x84)
+ELF_RELOC(R_RL78_OPscttop,    0x85)
+ELF_RELOC(R_RL78_OPlowH,      0x86)
+ELF_RELOC(R_RL78_OPlowL,      0x87)
+ELF_RELOC(R_RL78_OPhighW,     0x88)
+ELF_RELOC(R_RL78_OPlowW,      0x89)
+ELF_RELOC(R_RL78_OPhighW_MIR, 0x8a)
+ELF_RELOC(R_RL78_OPlowW_MIR,  0x8b)
+ELF_RELOC(R_RL78_OPlowW_SMIR, 0x8c)
+ELF_RELOC(R_RL78_OPmir,       0x8d)
+ELF_RELOC(R_RL78_OPABSlowH,   0xa6)
+ELF_RELOC(R_RL78_OPABSlowL,   0xa7)
+ELF_RELOC(R_RL78_OPABShighW,  0xa8)
+ELF_RELOC(R_RL78_OPABSlowW,   0xa9)
\ No newline at end of file
Index: llvm/include/llvm/Object/ELFObjectFile.h
===================================================================
--- llvm/include/llvm/Object/ELFObjectFile.h
+++ llvm/include/llvm/Object/ELFObjectFile.h
@@ -1225,6 +1225,8 @@
       return "elf32-loongarch";
     case ELF::EM_XTENSA:
       return "elf32-xtensa";
+    case ELF::EM_RL78:
+      return "elf32-rl78";
     default:
       return "elf32-unknown";
     }
@@ -1352,6 +1354,9 @@
   case ELF::EM_XTENSA:
     return Triple::xtensa;
 
+  case ELF::EM_RL78:
+    return Triple::rl78;
+
   default:
     return Triple::UnknownArch;
   }
Index: llvm/include/module.modulemap
===================================================================
--- llvm/include/module.modulemap
+++ llvm/include/module.modulemap
@@ -104,6 +104,7 @@
     textual header "llvm/BinaryFormat/ELFRelocs/VE.def"
     textual header "llvm/BinaryFormat/ELFRelocs/x86_64.def"
     textual header "llvm/BinaryFormat/ELFRelocs/Xtensa.def"
+    textual header "llvm/BinaryFormat/ELFRelocs/RL78.def"
     textual header "llvm/BinaryFormat/WasmRelocs.def"
     textual header "llvm/BinaryFormat/MsgPack.def"
 }
Index: llvm/lib/Object/ELF.cpp
===================================================================
--- llvm/lib/Object/ELF.cpp
+++ llvm/lib/Object/ELF.cpp
@@ -180,6 +180,12 @@
       break;
     }
     break;
+  case ELF::EM_RL78:
+    switch (Type) {
+#include "llvm/BinaryFormat/ELFRelocs/RL78.def"
+    default:
+      break;
+    }
   default:
     break;
   }
Index: llvm/lib/ObjectYAML/ELFYAML.cpp
===================================================================
--- llvm/lib/ObjectYAML/ELFYAML.cpp
+++ llvm/lib/ObjectYAML/ELFYAML.cpp
@@ -636,6 +636,22 @@
       break;
     }
     break;
+  case ELF::EM_RL78:
+    BCase(EF_RL78_FU_EXIST);
+    BCase(EF_RL78_EI_EXIST);
+    BCaseMask(EF_RL78_MAA_0, EF_RL78_MAA_1);
+    BCaseMask(EF_RL78_MAA_1, EF_RL78_MAA_1);
+    BCaseMask(EF_RL78_CPU_8BIT, EF_RL78_CPU_16BIT);
+    BCaseMask(EF_RL78_CPU_16BIT, EF_RL78_CPU_16BIT);
+    BCaseMask(EF_RL78_DOUBLE_4, EF_RL78_DOUBLE_8);
+    BCaseMask(EF_RL78_DOUBLE_8, EF_RL78_DOUBLE_8);
+    BCaseMask(EF_RL78_TEXT_NEAR, EF_RL78_TEXT_FAR);
+    BCaseMask(EF_RL78_TEXT_FAR, EF_RL78_TEXT_FAR);
+    BCaseMask(EF_RL78_DATA_NEAR, EF_RL78_DATA_FAR);
+    BCaseMask(EF_RL78_DATA_FAR, EF_RL78_DATA_FAR);
+    BCaseMask(EF_RL78_RODATA_NEAR, EF_RL78_RODATA_FAR);
+    BCaseMask(EF_RL78_RODATA_FAR, EF_RL78_RODATA_FAR);
+    break;
   default:
     break;
   }
@@ -915,6 +931,9 @@
   case ELF::EM_XTENSA:
 #include "llvm/BinaryFormat/ELFRelocs/Xtensa.def"
     break;
+  case ELF::EM_RL78:
+#include "llvm/BinaryFormat/ELFRelocs/RL78.def"
+    break;
   default:
     // Nothing to do.
     break;
Index: llvm/test/tools/llvm-readobj/ELF/reloc-types-rl78.test
===================================================================
--- /dev/null
+++ llvm/test/tools/llvm-readobj/ELF/reloc-types-rl78.test
@@ -0,0 +1,164 @@
+## Test that llvm-readobj shows proper relocation type
+## names and values for the RL78 target.
+
+# RUN: yaml2obj %s -o %t-rl78.o
+# RUN: llvm-readobj -r %t-rl78.o | FileCheck %s
+
+# CHECK:      0x0 R_RL78_NONE - 0x0
+# CHECK-NEXT: 0x4 R_RL78_DIR3U - 0x0
+# CHECK-NEXT: 0x8 R_RL78_DIR8U - 0x0
+# CHECK-NEXT: 0xC R_RL78_DIR16U - 0x0
+# CHECK-NEXT: 0x10 R_RL78_DIR20U - 0x0
+# CHECK-NEXT: 0x14 R_RL78_DIR20U_16 - 0x0
+# CHECK-NEXT: 0x18 R_RL78_DIR20UW_16 - 0x0
+# CHECK-NEXT: 0x1C R_RL78_DIR32U - 0x0
+# CHECK-NEXT: 0x20 R_RL78_DIR8U_MIR - 0x0
+# CHECK-NEXT: 0x24 R_RL78_DIR16U_MIR - 0x0
+# CHECK-NEXT: 0x28 R_RL78_DIR16UW_MIR - 0x0
+# CHECK-NEXT: 0x2C R_RL78_DIR8U_SAD - 0x0
+# CHECK-NEXT: 0x30 R_RL78_DIR8UW_SAD - 0x0
+# CHECK-NEXT: 0x34 R_RL78_DIR16U_RAM - 0x0
+# CHECK-NEXT: 0x38 R_RL78_DIR16UW_RAM - 0x0
+# CHECK-NEXT: 0x3C R_RL78_DIR8S_PCREL - 0x0
+# CHECK-NEXT: 0x40 R_RL78_DIR16S_PCREL - 0x0
+# CHECK-NEXT: 0x44 R_RL78_DIR_CALLT - 0x0
+# CHECK-NEXT: 0x48 R_RL78_ABS3U - 0x0
+# CHECK-NEXT: 0x4C R_RL78_ABS8U - 0x0
+# CHECK-NEXT: 0x50 R_RL78_ABS8UW - 0x0
+# CHECK-NEXT: 0x54 R_RL78_ABS16U - 0x0
+# CHECK-NEXT: 0x58 R_RL78_ABS16UW - 0x0
+# CHECK-NEXT: 0x5C R_RL78_ABS20U - 0x0
+# CHECK-NEXT: 0x60 R_RL78_ABS20U_16 - 0x0
+# CHECK-NEXT: 0x64 R_RL78_ABS20UW_16 - 0x0
+# CHECK-NEXT: 0x66 R_RL78_ABS32U - 0x0
+# CHECK-NEXT: 0x68 R_RL78_ABS8S_PCREL - 0x0
+# CHECK-NEXT: 0x6C R_RL78_ABS16S_PCREL - 0x0
+# CHECK-NEXT: 0x70 R_RL78_ABS_CALLT - 0x0
+# CHECK-NEXT: 0x74 R_RL78_REF - 0x0
+# CHECK-NEXT: 0x78 R_RL78_SYM - 0x0
+# CHECK-NEXT: 0x7C R_RL78_SYM_MIR - 0x0
+# CHECK-NEXT: 0x80 R_RL78_OPadd - 0x0
+# CHECK-NEXT: 0x84 R_RL78_OPsub - 0x0
+# CHECK-NEXT: 0x88 R_RL78_OPsctsize - 0x0
+# CHECK-NEXT: 0x8C R_RL78_OPscttop - 0x0
+# CHECK-NEXT: 0x90 R_RL78_OPlowH - 0x0
+# CHECK-NEXT: 0x94 R_RL78_OPlowL - 0x0
+# CHECK-NEXT: 0x95 R_RL78_OPhighW - 0x0
+# CHECK-NEXT: 0x96 R_RL78_OPlowW - 0x0
+# CHECK-NEXT: 0x98 R_RL78_OPhighW_MIR - 0x0
+# CHECK-NEXT: 0x9C R_RL78_OPlowW_MIR - 0x0
+# CHECK-NEXT: 0xA0 R_RL78_OPlowW_SMIR - 0x0
+# CHECK-NEXT: 0xA4 R_RL78_OPmir - 0x0
+# CHECK-NEXT: 0xA8 R_RL78_OPABSlowH - 0x0
+# CHECK-NEXT: 0xAC R_RL78_OPABSlowL - 0x0
+# CHECK-NEXT: 0xB0 R_RL78_OPABShighW - 0x0
+# CHECK-NEXT: 0xB4 R_RL78_OPABSlowW - 0x0
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS32
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_RL78
+Sections:
+  - Name:         .rela.text
+    Type:         SHT_RELA
+    Relocations:
+       - Offset: 0x0000000000000000
+         Type:   R_RL78_NONE
+       - Offset: 0x0000000000000004
+         Type:   R_RL78_DIR3U
+       - Offset: 0x0000000000000008
+         Type:   R_RL78_DIR8U
+       - Offset: 0x000000000000000C
+         Type:   R_RL78_DIR16U
+       - Offset: 0x0000000000000010
+         Type:   R_RL78_DIR20U
+       - Offset: 0x0000000000000014
+         Type:   R_RL78_DIR20U_16
+       - Offset: 0x0000000000000018
+         Type:   R_RL78_DIR20UW_16
+       - Offset: 0x000000000000001C
+         Type:   R_RL78_DIR32U
+       - Offset: 0x0000000000000020
+         Type:   R_RL78_DIR8U_MIR
+       - Offset: 0x0000000000000024
+         Type:   R_RL78_DIR16U_MIR
+       - Offset: 0x0000000000000028
+         Type:   R_RL78_DIR16UW_MIR
+       - Offset: 0x000000000000002C
+         Type:   R_RL78_DIR8U_SAD
+       - Offset: 0x0000000000000030
+         Type:   R_RL78_DIR8UW_SAD
+       - Offset: 0x0000000000000034
+         Type:   R_RL78_DIR16U_RAM
+       - Offset: 0x0000000000000038
+         Type:   R_RL78_DIR16UW_RAM
+       - Offset: 0x000000000000003C
+         Type:   R_RL78_DIR8S_PCREL
+       - Offset: 0x0000000000000040
+         Type:   R_RL78_DIR16S_PCREL
+       - Offset: 0x0000000000000044
+         Type:   R_RL78_DIR_CALLT
+       - Offset: 0x0000000000000048
+         Type:   R_RL78_ABS3U
+       - Offset: 0x000000000000004C
+         Type:   R_RL78_ABS8U
+       - Offset: 0x0000000000000050
+         Type:   R_RL78_ABS8UW
+       - Offset: 0x0000000000000054
+         Type:   R_RL78_ABS16U
+       - Offset: 0x0000000000000058
+         Type:   R_RL78_ABS16UW
+       - Offset: 0x000000000000005C
+         Type:   R_RL78_ABS20U
+       - Offset: 0x0000000000000060
+         Type:   R_RL78_ABS20U_16
+       - Offset: 0x0000000000000064
+         Type:   R_RL78_ABS20UW_16
+       - Offset: 0x0000000000000066
+         Type:   R_RL78_ABS32U
+       - Offset: 0x0000000000000068
+         Type:   R_RL78_ABS8S_PCREL
+       - Offset: 0x000000000000006C
+         Type:   R_RL78_ABS16S_PCREL
+       - Offset: 0x0000000000000070
+         Type:   R_RL78_ABS_CALLT
+       - Offset: 0x0000000000000074
+         Type:   R_RL78_REF
+       - Offset: 0x0000000000000078
+         Type:   R_RL78_SYM
+       - Offset: 0x000000000000007C
+         Type:   R_RL78_SYM_MIR
+       - Offset: 0x0000000000000080
+         Type:   R_RL78_OPadd
+       - Offset: 0x0000000000000084
+         Type:   R_RL78_OPsub
+       - Offset: 0x0000000000000088
+         Type:   R_RL78_OPsctsize
+       - Offset: 0x000000000000008C
+         Type:   R_RL78_OPscttop
+       - Offset: 0x0000000000000090
+         Type:   R_RL78_OPlowH
+       - Offset: 0x0000000000000094
+         Type:   R_RL78_OPlowL
+       - Offset: 0x0000000000000095
+         Type:   R_RL78_OPhighW
+       - Offset: 0x0000000000000096
+         Type:   R_RL78_OPlowW
+       - Offset: 0x0000000000000098
+         Type:   R_RL78_OPhighW_MIR
+       - Offset: 0x000000000000009C
+         Type:   R_RL78_OPlowW_MIR
+       - Offset: 0x00000000000000A0
+         Type:   R_RL78_OPlowW_SMIR
+       - Offset: 0x00000000000000A4
+         Type:   R_RL78_OPmir
+       - Offset: 0x00000000000000A8
+         Type:   R_RL78_OPABSlowH
+       - Offset: 0x00000000000000AC
+         Type:   R_RL78_OPABSlowL
+       - Offset: 0x00000000000000B0
+         Type:   R_RL78_OPABShighW
+       - Offset: 0x00000000000000B4
+         Type:   R_RL78_OPABSlowW
Index: llvm/test/tools/llvm-readobj/ELF/rl78-header-flags.test
===================================================================
--- /dev/null
+++ llvm/test/tools/llvm-readobj/ELF/rl78-header-flags.test
@@ -0,0 +1,68 @@
+## Check that we are able to dump EF_RL78_* flags correctly
+
+# RUN: yaml2obj %s -o %t.fu_exist -DFLAG=FU_EXIST
+# RUN: llvm-readobj -S --file-headers %t.fu_exist | FileCheck --check-prefixes=ALL,FU_EXIST %s
+
+# RUN: yaml2obj %s -o %t.ei_exist -DFLAG=EI_EXIST
+# RUN: llvm-readobj -S --file-headers %t.ei_exist | FileCheck --check-prefixes=ALL,EI_EXIST %s
+
+# RUN: yaml2obj %s -o %t.maa_0 -DFLAG=MAA_0
+# RUN: llvm-readobj -S --file-headers %t.maa_0 | FileCheck --check-prefixes=ALL,MAA_0 %s
+
+# RUN: yaml2obj %s -o %t.maa_1 -DFLAG=MAA_1
+# RUN: llvm-readobj -S --file-headers %t.maa_1 | FileCheck --check-prefixes=ALL,MAA_1 %s
+
+# RUN: yaml2obj %s -o %t.cpu_8bit -DFLAG=CPU_8BIT
+# RUN: llvm-readobj -S --file-headers %t.cpu_8bit | FileCheck --check-prefixes=ALL,CPU_8BIT %s
+
+# RUN: yaml2obj %s -o %t.cpu_16bit -DFLAG=CPU_16BIT
+# RUN: llvm-readobj -S --file-headers %t.cpu_16bit | FileCheck --check-prefixes=ALL,CPU_16BIT %s
+
+# RUN: yaml2obj %s -o %t.double_4 -DFLAG=DOUBLE_4
+# RUN: llvm-readobj -S --file-headers %t.double_4 | FileCheck --check-prefixes=ALL,DOUBLE_4 %s
+
+# RUN: yaml2obj %s -o %t.double_8 -DFLAG=DOUBLE_8
+# RUN: llvm-readobj -S --file-headers %t.double_8 | FileCheck --check-prefixes=ALL,DOUBLE_8 %s
+
+# RUN: yaml2obj %s -o %t.text_near -DFLAG=TEXT_NEAR
+# RUN: llvm-readobj -S --file-headers %t.text_near | FileCheck --check-prefixes=ALL,TEXT_NEAR %s
+
+# RUN: yaml2obj %s -o %t.text_far -DFLAG=TEXT_FAR
+# RUN: llvm-readobj -S --file-headers %t.text_far | FileCheck --check-prefixes=ALL,TEXT_FAR %s
+
+# RUN: yaml2obj %s -o %t.data_near -DFLAG=DATA_NEAR
+# RUN: llvm-readobj -S --file-headers %t.data_near | FileCheck --check-prefixes=ALL,DATA_NEAR %s
+
+# RUN: yaml2obj %s -o %t.data_far -DFLAG=DATA_FAR
+# RUN: llvm-readobj -S --file-headers %t.data_far | FileCheck --check-prefixes=ALL,DATA_FAR %s
+
+# RUN: yaml2obj %s -o %t.rodata_near -DFLAG=RODATA_NEAR
+# RUN: llvm-readobj -S --file-headers %t.rodata_near | FileCheck --check-prefixes=ALL,RODATA_NEAR %s
+
+# RUN: yaml2obj %s -o %t.rodata_far -DFLAG=RODATA_FAR
+# RUN: llvm-readobj -S --file-headers %t.rodata_far | FileCheck --check-prefixes=ALL,RODATA_FAR %s
+
+# ALL:  Flags [
+# FU_EXIST:  EF_RL78_FU_EXIST (0x1)
+# EI_EXIST:  EF_RL78_EI_EXIST (0x8)
+# MAA_0:  EF_RL78_MAA_0 (0x40)
+# MAA_1:  EF_RL78_MAA_1 (0xC0)
+# CPU_8BIT:  EF_RL78_CPU_8BIT (0x100)
+# CPU_16BIT:  EF_RL78_CPU_16BIT (0x300)
+# DOUBLE_4:  EF_RL78_DOUBLE_4 (0x400)
+# DOUBLE_8:  EF_RL78_DOUBLE_8 (0xC00)
+# TEXT_NEAR:  EF_RL78_TEXT_NEAR (0x1000)
+# TEXT_FAR:  EF_RL78_TEXT_FAR (0x3000)
+# DATA_NEAR:  EF_RL78_DATA_NEAR (0x4000)
+# DATA_FAR:  EF_RL78_DATA_FAR (0xC000)
+# RODATA_NEAR:  EF_RL78_RODATA_NEAR (0x10000)
+# RODATA_FAR:  EF_RL78_RODATA_FAR (0x30000)
+# ALL:  ]
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS32
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_RL78
+  Flags:   [ EF_RL78_[[FLAG]] ]
Index: llvm/tools/llvm-readobj/ELFDumper.cpp
===================================================================
--- llvm/tools/llvm-readobj/ELFDumper.cpp
+++ llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -1720,6 +1720,23 @@
   LLVM_READOBJ_ENUM_ENT(ELF, EF_XTENSA_XT_LIT)
 };
 
+const EnumEntry<unsigned> ElfHeaderRL78Flags[] = {
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_FU_EXIST),
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_EI_EXIST),
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_MAA_1),
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_MAA_0),
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_CPU_16BIT),
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_CPU_8BIT),
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_DOUBLE_8),
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_DOUBLE_4),
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_TEXT_FAR),
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_TEXT_NEAR),
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_DATA_FAR),
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_DATA_NEAR),
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_RODATA_FAR),
+  LLVM_READOBJ_ENUM_ENT(ELF, EF_RL78_RODATA_NEAR)
+};
+
 const EnumEntry<unsigned> ElfSymOtherFlags[] = {
   LLVM_READOBJ_ENUM_ENT(ELF, STV_INTERNAL),
   LLVM_READOBJ_ENUM_ENT(ELF, STV_HIDDEN),
@@ -3595,6 +3612,9 @@
   else if (e.e_machine == EM_XTENSA)
     ElfFlags = printFlags(e.e_flags, ArrayRef(ElfHeaderXtensaFlags),
                           unsigned(ELF::EF_XTENSA_MACH));
+  else if (e.e_machine == EM_RL78)
+    ElfFlags = printFlags(e.e_flags, ArrayRef(ElfHeaderRL78Flags),
+                          unsigned(ELF::EF_RL78_MASK));
   Str = "0x" + utohexstr(e.e_flags);
   if (!ElfFlags.empty())
     Str = Str + ", " + ElfFlags;
@@ -6834,6 +6854,9 @@
     else if (E.e_machine == EM_XTENSA)
       W.printFlags("Flags", E.e_flags, ArrayRef(ElfHeaderXtensaFlags),
                    unsigned(ELF::EF_XTENSA_MACH));
+    else if (E.e_machine == EM_RL78)
+      W.printFlags("Flags", E.e_flags, ArrayRef(ElfHeaderRL78Flags),
+                   unsigned(ELF::EF_RL78_MASK));
     else
       W.printFlags("Flags", E.e_flags);
     W.printNumber("HeaderSize", E.e_ehsize);
Index: llvm/unittests/Object/ELFObjectFileTest.cpp
===================================================================
--- llvm/unittests/Object/ELFObjectFileTest.cpp
+++ llvm/unittests/Object/ELFObjectFileTest.cpp
@@ -286,6 +286,13 @@
     checkFormatAndArch(Data, Formats[Idx], Triple::xtensa);
 }
 
+TEST(ELFObjectFileTest, MachineTestForRL78) {
+  std::array<StringRef, 4> Formats = {"elf32-rl78", "elf32-rl78",
+                                      "elf64-unknown", "elf64-unknown"};
+  for (auto [Idx, Data] : enumerate(generateData(ELF::EM_RL78)))
+    checkFormatAndArch(Data, Formats[Idx], Triple::rl78);
+}
+
 // ELF relative relocation type test.
 TEST(ELFObjectFileTest, RelativeRelocationTypeTest) {
   EXPECT_EQ(ELF::R_CKCORE_RELATIVE, getELFRelativeRelocationType(ELF::EM_CSKY));