Add backend support for C-SKY

C-SKY V2 ABI manual:
https://github.com/c-sky/csky-doc/blob/master/C-SKY_V2_CPU_Applications_Binary_Interface_Standards_Manual.pdf
C-SKY architecture user guide:
https://github.com/c-sky/csky-doc/blob/master/CSKY%20Architecture%20user_guide.pdf

Signed-off-by: Mao Han <han_mao@c-sky.com>

21 files changed, 692 insertions, 6 deletions

diff --git a/backends/ChangeLog b/backends/ChangeLog
index af1a40e2..f1eaf14b 100644
--- a/backends/ChangeLog
+++ b/backends/ChangeLog
@@ -1,3 +1,15 @@
+2019-07-13 Mao Han <han_mao@c-sky.com>
+
+	* Makefile.am: Add C-SKY.
+	* csky_attrs.c: New file.
+	* csky_cfi.c: New file.
+	* csky_corenote.c: Likewise.
+	* csky_init.c: Likewise.
+	* csky_initreg.c: Likewise.
+	* csky_regs.c: Likewise.
+	* csky_reloc.def: Likewise.
+	* csky_symbol.c: Likewise.
+
 2019-06-28  Mark Wielaard  <mark@klomp.org>
 
 	* aarch64_init.c (aarch64_init.c): Remove eh->name;
diff --git a/backends/Makefile.am b/backends/Makefile.am
index 2126a2ec..175468f6 100644
--- a/backends/Makefile.am
+++ b/backends/Makefile.am
@@ -33,12 +33,13 @@ AM_CPPFLAGS += -I$(top_srcdir)/libebl -I$(top_srcdir)/libasm \
 
 
 modules = i386 sh x86_64 ia64 alpha arm aarch64 sparc ppc ppc64 s390 \
-	  tilegx m68k bpf riscv
+	  tilegx m68k bpf riscv csky
 libebl_pic = libebl_i386_pic.a libebl_sh_pic.a libebl_x86_64_pic.a    \
 	     libebl_ia64_pic.a libebl_alpha_pic.a libebl_arm_pic.a    \
 	     libebl_aarch64_pic.a libebl_sparc_pic.a libebl_ppc_pic.a \
 	     libebl_ppc64_pic.a libebl_s390_pic.a libebl_tilegx_pic.a \
-	     libebl_m68k_pic.a libebl_bpf_pic.a libebl_riscv_pic.a
+	     libebl_m68k_pic.a libebl_bpf_pic.a libebl_riscv_pic.a    \
+	     libebl_csky_pic.a
 noinst_LIBRARIES = $(libebl_pic)
 noinst_DATA = $(libebl_pic:_pic.a=.so)
 
@@ -136,6 +137,10 @@ riscv_SRCS = riscv_init.c riscv_symbol.c riscv_cfi.c riscv_regs.c \
 libebl_riscv_pic_a_SOURCES = $(riscv_SRCS)
 am_libebl_riscv_pic_a_OBJECTS = $(riscv_SRCS:.c=.os)
 
+csky_SRCS = csky_attrs.c csky_init.c csky_symbol.c csky_cfi.c \
+	    csky_regs.c csky_initreg.c csky_corenote.c
+libebl_csky_pic_a_SOURCES = $(csky_SRCS)
+am_libebl_csky_pic_a_OBJECTS = $(csky_SRCS:.c=.os)
 
 libebl_%.so libebl_%.map: libebl_%_pic.a $(libelf) $(libdw) $(libeu)
 	@rm -f $(@:.so=.map)
diff --git a/backends/csky_attrs.c b/backends/csky_attrs.c
new file mode 100644
index 00000000..177f0ba2
--- /dev/null
+++ b/backends/csky_attrs.c
@@ -0,0 +1,67 @@
+/* C-SKY ABI-specified defaults for DWARF CFI.
+   Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <string.h>
+#include <dwarf.h>
+
+#define BACKEND csky_
+#include "libebl_CPU.h"
+
+bool
+csky_check_object_attribute (Ebl *ebl __attribute__ ((unused)),
+			    const char *vendor, int tag,
+			    uint64_t value __attribute__ ((unused)),
+			    const char **tag_name,
+			    const char **value_name __attribute__ ((unused)))
+{
+  if (!strcmp (vendor, "csky"))
+    switch (tag)
+      {
+      case 4:
+	*tag_name = "CSKY_ARCH_NAME";
+	return true;
+
+      case 5:
+	*tag_name = "CSKY_CPU_NAME";
+	return true;
+
+      case 6:
+        *tag_name = "CSKY_ISA_FLAGS";
+        return true;
+
+      case 7:
+        *tag_name = "CSKY_ISA_EXT_FLAGS";
+        return true;
+      }
+
+  return false;
+}
diff --git a/backends/csky_cfi.c b/backends/csky_cfi.c
new file mode 100644
index 00000000..7277dbd4
--- /dev/null
+++ b/backends/csky_cfi.c
@@ -0,0 +1,60 @@
+/* C-SKY ABI-specified defaults for DWARF CFI.
+   Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <dwarf.h>
+
+#define BACKEND csky_
+#include "libebl_CPU.h"
+
+
+int
+csky_abi_cfi (Ebl *ebl __attribute__ ((unused)), Dwarf_CIE *abi_info)
+{
+  static const uint8_t abi_cfi[] =
+    {
+      DW_CFA_def_cfa, ULEB128_7 (14), ULEB128_7 (0),
+      DW_CFA_val_offset, ULEB128_7 (14), ULEB128_7 (0),
+
+#define SV(n) DW_CFA_same_value, ULEB128_7 (n)
+      SV(4), SV (5), SV (6), SV (7), SV (8), SV (9),
+      SV(10), SV (11), SV (15), SV (16), SV (17)
+#undef SV
+    };
+
+  abi_info->initial_instructions = abi_cfi;
+  abi_info->initial_instructions_end = &abi_cfi[sizeof abi_cfi];
+  abi_info->data_alignment_factor = -4;
+
+  abi_info->return_address_register = 15; /* lr.  */
+
+  return 0;
+}
diff --git a/backends/csky_corenote.c b/backends/csky_corenote.c
new file mode 100644
index 00000000..a1479bd3
--- /dev/null
+++ b/backends/csky_corenote.c
@@ -0,0 +1,61 @@
+/* C-SKY specific core note handling.
+   Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <elf.h>
+#include <inttypes.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <sys/time.h>
+
+#define BACKEND	csky_
+#include "libebl_CPU.h"
+
+#define	ULONG			uint32_t
+#define PID_T			int32_t
+#define	UID_T			uint32_t
+#define	GID_T			uint32_t
+#define ALIGN_ULONG		4
+#define ALIGN_PID_T		4
+#define ALIGN_UID_T		4
+#define ALIGN_GID_T		4
+#define TYPE_ULONG		ELF_T_WORD
+#define TYPE_PID_T		ELF_T_SWORD
+#define TYPE_UID_T		ELF_T_WORD
+#define TYPE_GID_T		ELF_T_WORD
+
+static const Ebl_Register_Location prstatus_regs[] =
+  {
+    { .offset = 0, .regno = 0, .count = 36, .bits = 32 } /* r0..r31 */
+  };
+#define PRSTATUS_REGS_SIZE	(36 * 4)
+
+#include "linux-core-note.c"
diff --git a/backends/csky_init.c b/backends/csky_init.c
new file mode 100644
index 00000000..b34a03aa
--- /dev/null
+++ b/backends/csky_init.c
@@ -0,0 +1,65 @@
+/* Initialization of C-SKY specific backend library.
+   Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#define BACKEND		csky_
+#define RELOC_PREFIX	R_CKCORE_
+#include "libebl_CPU.h"
+
+/* This defines the common reloc hooks based on csky_reloc.def.  */
+#include "common-reloc.c"
+
+const char *
+csky_init (Elf *elf __attribute__ ((unused)),
+	   GElf_Half machine __attribute__ ((unused)),
+	   Ebl *eh,
+	   size_t ehlen)
+{
+  /* Check whether the Elf_BH object has a sufficent size.  */
+  if (ehlen < sizeof (Ebl))
+    return NULL;
+
+  /* We handle it.  */
+  csky_init_reloc (eh);
+  HOOK (eh, abi_cfi);
+  HOOK (eh, core_note);
+  HOOK (eh, check_object_attribute);
+  HOOK (eh, machine_flag_check);
+  HOOK (eh, reloc_simple_type);
+  HOOK (eh, register_info);
+  HOOK (eh, section_type_name);
+  HOOK (eh, set_initial_registers_tid);
+
+  /* gcc/config/ #define DWARF_FRAME_REGISTERS.  */
+  eh->frame_nregs = 38;
+
+  return MODVERSION;
+}
diff --git a/backends/csky_initreg.c b/backends/csky_initreg.c
new file mode 100644
index 00000000..81a0da33
--- /dev/null
+++ b/backends/csky_initreg.c
@@ -0,0 +1,87 @@
+/* Fetch live process registers from TID. C-SKY version.
+   Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "system.h"
+#include <assert.h>
+#if defined __CSKY__ && defined __linux__
+# include <sys/uio.h>
+# include <sys/procfs.h>
+# include <sys/ptrace.h>
+#endif
+
+#define BACKEND csky_
+#include "libebl_CPU.h"
+
+bool
+csky_set_initial_registers_tid (pid_t tid __attribute__ ((unused)),
+			ebl_tid_registers_t *setfunc __attribute__ ((unused)),
+				void *arg __attribute__ ((unused)))
+{
+#if !defined __CSKY__ || !defined __linux__
+  return false;
+#else /* __CSKY__ */
+  struct pt_regs user_regs;
+  struct iovec iovec;
+  iovec.iov_base = &user_regs;
+  iovec.iov_len = sizeof (user_regs);
+  if (ptrace (PTRACE_GETREGSET, tid, NT_PRSTATUS, &iovec) != 0)
+    return false;
+
+  Dwarf_Word dwarf_regs[38];
+
+  /* lr.  */
+  dwarf_regs[15] = user_regs.lr;
+  /* sp.  */
+  dwarf_regs[14] = user_regs.usp;
+  /* r0 ~ r13.  */
+  dwarf_regs[0] = user_regs.a0;
+  dwarf_regs[1] = user_regs.a1;
+  dwarf_regs[2] = user_regs.a2;
+  dwarf_regs[3] = user_regs.a3;
+  for (int i = 4; i < 14; i++)
+    dwarf_regs[i] = user_regs.regs[i - 4];
+  /* r ~ r13.  */
+  for (int i = 16; i < 31; i++)
+    dwarf_regs[i] = user_regs.exregs[i - 16];
+  /* tls.  */
+  dwarf_regs[31] = user_regs.tls;
+  /* hi.  */
+  dwarf_regs[36] = user_regs.rhi;
+  /* lo.  */
+  dwarf_regs[37] = user_regs.rlo;
+  /* pc.  */
+  dwarf_regs[32] = user_regs.pc;
+  setfunc (-1, 1, &dwarf_regs[32], arg);
+
+  return setfunc (0, 38, dwarf_regs, arg);
+#endif
+}
diff --git a/backends/csky_regs.c b/backends/csky_regs.c
new file mode 100644
index 00000000..6d45c04b
--- /dev/null
+++ b/backends/csky_regs.c
@@ -0,0 +1,101 @@
+/* Register names and numbers for C-SKY DWARF.
+   Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <string.h>
+#include <dwarf.h>
+
+#define BACKEND csky_
+#include "libebl_CPU.h"
+
+ssize_t
+csky_register_info (Ebl *ebl  __attribute__ ((unused)),
+		    int regno, char *name, size_t namelen,
+		    const char **prefix, const char **setname,
+		    int *bits, int *type)
+{
+  if (name == NULL)
+    return 38;
+
+  *prefix = "";
+  *bits = 32;
+  *type = DW_ATE_signed;
+  *setname = "integer";
+
+  switch (regno)
+    {
+    case 0 ... 9:
+      name[0] = 'r';
+      name[1] = regno + '0';
+      namelen = 2;
+      break;
+
+    case 10 ... 13:
+    case 16 ... 30:
+      name[0] = 'r';
+      name[1] = regno / 10 + '0';
+      name[2] = regno % 10 + '0';
+      namelen = 3;
+      break;
+
+    case 14:
+      stpcpy (name, "sp");
+      namelen = 2;
+      break;
+
+    case 15:
+      stpcpy (name, "lr");
+      namelen = 2;
+      break;
+
+    case 31:
+      stpcpy (name, "tls");
+      namelen = 3;
+      break;
+
+    case 36:
+      stpcpy (name, "hi");
+      namelen = 2;
+      break;
+
+    case 37:
+      stpcpy (name, "lo");
+      namelen = 2;
+      break;
+
+    default:
+      *setname = NULL;
+      return 0;
+    }
+
+  name[namelen++] = '\0';
+  return namelen;
+}
diff --git a/backends/csky_reloc.def b/backends/csky_reloc.def
new file mode 100644
index 00000000..1108f0c2
--- /dev/null
+++ b/backends/csky_reloc.def
@@ -0,0 +1,86 @@
+/* List the relocation types for csky.  -*- C -*-
+   Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+/*	    NAME,		REL|EXEC|DYN	*/
+
+
+RELOC_TYPE (NONE,		REL|EXEC|DYN)
+RELOC_TYPE (ADDR32,		REL|EXEC|DYN)
+RELOC_TYPE (PCRELIMM8BY4,	REL)
+RELOC_TYPE (PCRELIMM11BY2,	REL)
+RELOC_TYPE (PCREL32,		REL|DYN)
+RELOC_TYPE (PCRELJSR_IMM11BY2,	REL)
+RELOC_TYPE (RELATIVE,		EXEC|DYN)
+RELOC_TYPE (COPY,		EXEC|DYN)
+RELOC_TYPE (GLOB_DAT,		EXEC|DYN)
+RELOC_TYPE (JUMP_SLOT,		EXEC|DYN)
+RELOC_TYPE (GOTOFF,		REL)
+RELOC_TYPE (GOTPC,		REL)
+RELOC_TYPE (GOT32,		REL)
+RELOC_TYPE (PLT32,		REL)
+RELOC_TYPE (ADDRGOT,		REL)
+RELOC_TYPE (ADDRPLT,		REL)
+RELOC_TYPE (PCREL_IMM26BY2,	REL)
+RELOC_TYPE (PCREL_IMM16BY2,	REL)
+RELOC_TYPE (PCREL_IMM16BY4,	REL)
+RELOC_TYPE (PCREL_IMM10BY2,	REL)
+RELOC_TYPE (PCREL_IMM10BY4,	REL)
+RELOC_TYPE (ADDR_HI16,		REL|DYN)
+RELOC_TYPE (ADDR_LO16,		REL|DYN)
+RELOC_TYPE (GOTPC_HI16,		REL)
+RELOC_TYPE (GOTPC_LO16,		REL)
+RELOC_TYPE (GOTOFF_HI16,	REL)
+RELOC_TYPE (GOTOFF_LO16,	REL)
+RELOC_TYPE (GOT12,		REL)
+RELOC_TYPE (GOT_HI16,		REL)
+RELOC_TYPE (GOT_LO16,		REL)
+RELOC_TYPE (PLT12,		REL)
+RELOC_TYPE (PLT_HI16,		REL)
+RELOC_TYPE (PLT_LO16,		REL)
+RELOC_TYPE (ADDRGOT_HI16,	REL)
+RELOC_TYPE (ADDRGOT_LO16,	REL)
+RELOC_TYPE (ADDRPLT_HI16,	REL)
+RELOC_TYPE (ADDRPLT_LO16,	REL)
+RELOC_TYPE (PCREL_JSR_IMM26BY2,	REL|DYN)
+RELOC_TYPE (TOFFSET_LO16,	REL)
+RELOC_TYPE (DOFFSET_LO16,	REL)
+RELOC_TYPE (PCREL_IMM18BY2,	REL)
+RELOC_TYPE (DOFFSET_IMM18,	REL)
+RELOC_TYPE (DOFFSET_IMM18BY2,	REL)
+RELOC_TYPE (DOFFSET_IMM18BY4,	REL)
+RELOC_TYPE (GOT_IMM18BY4,	REL)
+RELOC_TYPE (PLT_IMM18BY4,	REL)
+RELOC_TYPE (PCREL_IMM7BY4,	REL)
+RELOC_TYPE (TLS_LE32,		REL)
+RELOC_TYPE (TLS_IE32,		REL)
+RELOC_TYPE (TLS_GD32,		REL)
+RELOC_TYPE (TLS_LDM32,		REL)
+RELOC_TYPE (TLS_LDO32,		REL)
+RELOC_TYPE (TLS_DTPMOD32,	EXEC|DYN)
+RELOC_TYPE (TLS_DTPOFF32,	EXEC|DYN)
+RELOC_TYPE (TLS_TPOFF32,	EXEC|DYN)
diff --git a/backends/csky_symbol.c b/backends/csky_symbol.c
new file mode 100644
index 00000000..79b5bf9e
--- /dev/null
+++ b/backends/csky_symbol.c
@@ -0,0 +1,77 @@
+/* C-SKY specific symbolic name handling.
+   Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <assert.h>
+#include <elf.h>
+#include <stddef.h>
+#include <string.h>
+
+#define BACKEND csky_
+#include "libebl_CPU.h"
+
+/* Check for the simple reloc types.  */
+Elf_Type
+csky_reloc_simple_type (Ebl *ebl __attribute__ ((unused)), int type,
+			int *addsub __attribute__ ((unused)))
+{
+  switch (type)
+    {
+    case R_CKCORE_ADDR32:
+      return ELF_T_WORD;
+    default:
+      return ELF_T_NUM;
+    }
+}
+
+bool
+csky_machine_flag_check (GElf_Word flags)
+{
+  switch (flags & EF_CSKY_ABIMASK)
+    {
+    case EF_CSKY_ABIV2:
+      return true;
+    case EF_CSKY_ABIV1:
+    default:
+      return false;
+    }
+}
+
+const char *
+csky_section_type_name (int type,
+		       char *buf __attribute__ ((unused)),
+		       size_t len __attribute__ ((unused)))
+{
+  if (type == SHT_CSKY_ATTRIBUTES)
+    return "CSKY_ATTRIBUTES";
+
+  return NULL;
+}
diff --git a/libebl/ChangeLog b/libebl/ChangeLog
index e42cd34b..bb91c152 100644
--- a/libebl/ChangeLog
+++ b/libebl/ChangeLog
@@ -1,3 +1,7 @@
+2019-04-29 Mao Han <han_mao@c-sky.com>
+
+	* eblopenbackend.c: Add C-SKY.
+
 2019-06-28  Mark Wielaard  <mark@klomp.org>
 
 	* eblopenbackend.c (try_dlopen): Remove result->name check.
diff --git a/libebl/eblopenbackend.c b/libebl/eblopenbackend.c
index 9dd51950..01711f5e 100644
--- a/libebl/eblopenbackend.c
+++ b/libebl/eblopenbackend.c
@@ -135,6 +135,7 @@ static const struct
   { "bpf", "elf_bpf", "bpf", 3, EM_BPF, 0, 0 },
   { "riscv", "elf_riscv", "riscv", 5, EM_RISCV, ELFCLASS64, ELFDATA2LSB },
   { "riscv", "elf_riscv", "riscv", 5, EM_RISCV, ELFCLASS32, ELFDATA2LSB },
+  { "csky", "elf_csky", "csky", 4, EM_CSKY, ELFCLASS32, ELFDATA2LSB },
 };
 #define nmachines (sizeof (machines) / sizeof (machines[0]))
 
diff --git a/src/ChangeLog b/src/ChangeLog
index 27812b05..911ad26f 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2019-07-13 Mao Han <han_mao@c-sky.com>
+
+	* elflint.c: Add C-SKY.
+
 2019-06-28  Mark Wielaard  <mark@klomp.org>
 
 	* readelf.c (print_ehdr): Use dwelf_elf_e_machine_string instead of
diff --git a/src/elflint.c b/src/elflint.c
index 810c8bd7..edb466dd 100644
--- a/src/elflint.c
+++ b/src/elflint.c
@@ -330,7 +330,7 @@ static const int valid_e_machine[] =
     EM_CRIS, EM_JAVELIN, EM_FIREPATH, EM_ZSP, EM_MMIX, EM_HUANY, EM_PRISM,
     EM_AVR, EM_FR30, EM_D10V, EM_D30V, EM_V850, EM_M32R, EM_MN10300,
     EM_MN10200, EM_PJ, EM_OPENRISC, EM_ARC_A5, EM_XTENSA, EM_ALPHA,
-    EM_TILEGX, EM_TILEPRO, EM_AARCH64, EM_BPF, EM_RISCV
+    EM_TILEGX, EM_TILEPRO, EM_AARCH64, EM_BPF, EM_RISCV, EM_CSKY
   };
 #define nvalid_e_machine \
   (sizeof (valid_e_machine) / sizeof (valid_e_machine[0]))
diff --git a/src/readelf.c b/src/readelf.c
index cda7c93a..2084fb1f 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -3571,7 +3571,9 @@ print_attributes (Ebl *ebl, const GElf_Ehdr *ehdr)
 
       if (shdr == NULL || (shdr->sh_type != SHT_GNU_ATTRIBUTES
 			   && (shdr->sh_type != SHT_ARM_ATTRIBUTES
-			       || ehdr->e_machine != EM_ARM)))
+			       || ehdr->e_machine != EM_ARM)
+			   && (shdr->sh_type != SHT_CSKY_ATTRIBUTES
+			       || ehdr->e_machine != EM_CSKY)))
 	continue;
 
       printf (gettext ("\
diff --git a/tests/ChangeLog b/tests/ChangeLog
index 81621851..63d6af96 100644
--- a/tests/ChangeLog
+++ b/tests/ChangeLog
@@ -1,3 +1,12 @@
+2019-07-16  Mao Han  <han_mao@c-sky.com>
+
+	* hello_csky.ko.bz2: New testfile.
+	* run-addrcfi.sh: Add C-SKY testfile.
+	* run-strip-reloc.sh: Likewise.
+	* testfilecsky.bz2: New testfile.
+	* Makefile.am (EXTRA_DIST): Add hello_csky.ko.bz2 and
+	testfilecsky.bz2.
+
 2019-06-28  Mark Wielaard  <mark@klomp.org>
 
 	* Makefile.am (check_PROGRAMS): Add dwelf_elf_e_machine_string.
diff --git a/tests/Makefile.am b/tests/Makefile.am
index a605d080..0ac35315 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -212,7 +212,7 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh run-ar.sh \
 	     testfile-nobitsalign.bz2 testfile-nobitsalign.strip.bz2 \
 	     run-strip-reloc.sh hello_i386.ko.bz2 hello_x86_64.ko.bz2 \
 	     hello_ppc64.ko.bz2 hello_s390.ko.bz2 hello_aarch64.ko.bz2 \
-	     hello_m68k.ko.bz2 hello_riscv64.ko.bz2 \
+	     hello_m68k.ko.bz2 hello_riscv64.ko.bz2 hello_csky.ko.bz2 \
 	     run-unstrip-test.sh run-unstrip-test2.sh \
 	     testfile-info-link.bz2 testfile-info-link.debuginfo.bz2 \
 	     testfile-info-link.stripped.bz2 run-unstrip-test3.sh \
@@ -229,6 +229,7 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh run-ar.sh \
 	     testfile11-debugframe.bz2 testfile12-debugframe.bz2 \
 	     testfileaarch64-debugframe.bz2 testfilearm-debugframe.bz2 \
 	     testfileppc32-debugframe.bz2 testfileppc64-debugframe.bz2 \
+	     testfilecsky.bz2 \
 	     run-varlocs-self.sh run-exprlocs-self.sh \
 	     run-find-prologues.sh run-allregs.sh run-native-test.sh \
 	     run-addrname-test.sh run-dwfl-bug-offline-rel.sh \
diff --git a/tests/hello_csky.ko.bz2 b/tests/hello_csky.ko.bz2
new file mode 100644
index 00000000..ed98c7f6
--- /dev/null
+++ b/tests/hello_csky.ko.bz2
diff --git a/tests/run-addrcfi.sh b/tests/run-addrcfi.sh
index fd89d025..64fa24d7 100755
--- a/tests/run-addrcfi.sh
+++ b/tests/run-addrcfi.sh
@@ -3747,3 +3747,46 @@ testrun_compare ${abs_builddir}/addrcfi -e testfile-x32 0x00400390 <<\EOF
 	control reg66 (%fsw): undefined
 handle_cfi no CFI (.debug_frame): no error
 EOF
+
+# EM_CSKY (function bar 0x8440)
+testfiles testfilecsky
+testrun_compare ${abs_builddir}/addrcfi -e testfilecsky 0x8440 <<\EOF
+dwarf_cfi_addrframe (.eh_frame): no matching address range
+.debug_frame has 0x8440 => [0x8440, 0x844a):
+	return address in reg15
+	CFA location expression: bregx(14)
+	integer reg0 (r0): undefined
+	integer reg1 (r1): undefined
+	integer reg2 (r2): undefined
+	integer reg3 (r3): undefined
+	integer reg4 (r4): same_value
+	integer reg5 (r5): same_value
+	integer reg6 (r6): same_value
+	integer reg7 (r7): same_value
+	integer reg8 (r8): same_value
+	integer reg9 (r9): same_value
+	integer reg10 (r10): same_value
+	integer reg11 (r11): same_value
+	integer reg12 (r12): undefined
+	integer reg13 (r13): undefined
+	integer reg14 (sp): location expression: call_frame_cfa stack_value
+	integer reg15 (lr): same_value
+	integer reg16 (r16): same_value
+	integer reg17 (r17): same_value
+	integer reg18 (r18): undefined
+	integer reg19 (r19): undefined
+	integer reg20 (r20): undefined
+	integer reg21 (r21): undefined
+	integer reg22 (r22): undefined
+	integer reg23 (r23): undefined
+	integer reg24 (r24): undefined
+	integer reg25 (r25): undefined
+	integer reg26 (r26): undefined
+	integer reg27 (r27): undefined
+	integer reg28 (r28): undefined
+	integer reg29 (r29): undefined
+	integer reg30 (r30): undefined
+	integer reg31 (tls): undefined
+	integer reg36 (hi): undefined
+	integer reg37 (lo): undefined
+EOF
diff --git a/tests/run-strip-reloc.sh b/tests/run-strip-reloc.sh
index 0c6b1c2c..b7ec1420 100755
--- a/tests/run-strip-reloc.sh
+++ b/tests/run-strip-reloc.sh
@@ -18,7 +18,7 @@
 . $srcdir/test-subr.sh
 
 testfiles hello_i386.ko hello_x86_64.ko hello_ppc64.ko hello_s390.ko \
-	hello_aarch64.ko hello_m68k.ko hello_riscv64.ko
+	hello_aarch64.ko hello_m68k.ko hello_riscv64.ko hello_csky.ko
 
 tempfiles readelf.out readelf.out1 readelf.out2
 tempfiles out.stripped1 out.debug1 out.stripped2 out.debug2
@@ -119,6 +119,7 @@ runtest hello_s390.ko 1
 runtest hello_aarch64.ko 1
 runtest hello_m68k.ko 1
 runtest hello_riscv64.ko 1
+runtest hello_csky.ko 1
 
 # self test, shouldn't impact non-ET_REL files at all.
 runtest ${abs_top_builddir}/src/strip 0
diff --git a/tests/testfilecsky.bz2 b/tests/testfilecsky.bz2
new file mode 100644
index 00000000..dfee449e
--- /dev/null
+++ b/tests/testfilecsky.bz2