Patchwork [RFC,V2,09/10] C-SKY: Linux Startup and Dynamic Loading Code

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Submitter Mao Han
Date April 8, 2018, 7:02 a.m.
Message ID <8ea658de41700d5db6211ed2e837fb1365d369af.1523169833.git.han_mao@c-sky.com>
Download mbox | patch
Permalink /patch/26651/
State New
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Comments

Mao Han - April 8, 2018, 7:02 a.m.
This contains the Linux-specific code for loading programs on C-SKY.

        * elf/elf.h: Add C-SKY relocale
        * sysdeps/csky/dl-machine.h: New file
        * sysdeps/csky/dl-procinfo.c: New file
        * sysdeps/csky/dl-procinfo.h: New file
        * sysdeps/csky/dl-sysdep.h: New file
        * sysdeps/csky/dl-tlsdesc.h: New file
        * sysdeps/csky/ldsodefs.h: New file
        * sysdeps/csky/linkmap.h: New file
        * sysdeps/csky/sotruss-lib.c: New file
        * sysdeps/unix/sysv/linux/csky/ldconfig.h: New file
---
 elf/elf.h                               |  67 ++++-
 sysdeps/csky/dl-machine.h               | 472 ++++++++++++++++++++++++++++++++
 sysdeps/csky/dl-procinfo.c              |  62 +++++
 sysdeps/csky/dl-procinfo.h              |  59 ++++
 sysdeps/csky/dl-sysdep.h                |  23 ++
 sysdeps/csky/dl-tlsdesc.h               |  61 +++++
 sysdeps/csky/ldsodefs.h                 |  42 +++
 sysdeps/csky/linkmap.h                  |   5 +
 sysdeps/csky/sotruss-lib.c              |  49 ++++
 sysdeps/unix/sysv/linux/csky/ldconfig.h |  24 ++
 10 files changed, 863 insertions(+), 1 deletion(-)
 create mode 100644 sysdeps/csky/dl-machine.h
 create mode 100644 sysdeps/csky/dl-procinfo.c
 create mode 100644 sysdeps/csky/dl-procinfo.h
 create mode 100644 sysdeps/csky/dl-sysdep.h
 create mode 100644 sysdeps/csky/dl-tlsdesc.h
 create mode 100644 sysdeps/csky/ldsodefs.h
 create mode 100644 sysdeps/csky/linkmap.h
 create mode 100644 sysdeps/csky/sotruss-lib.c
 create mode 100644 sysdeps/unix/sysv/linux/csky/ldconfig.h

Patch

diff --git a/elf/elf.h b/elf/elf.h
index f774898..c8f20a0 100644
--- a/elf/elf.h
+++ b/elf/elf.h
@@ -360,8 +360,9 @@  typedef struct
 #define EM_RISCV	243	/* RISC-V */
 
 #define EM_BPF		247	/* Linux BPF -- in-kernel virtual machine */
+#define EM_CSKY         252     /* C_SKY */
 
-#define EM_NUM		248
+#define EM_NUM		253
 
 /* Old spellings/synonyms.  */
 
@@ -3013,6 +3014,70 @@  enum
 /* Keep this the last entry.  */
 #define R_ARM_NUM		256
 
+/* csky */
+#define R_CKCORE_NONE               0	/* no reloc */
+#define R_CKCORE_ADDR32             1	/* direct 32 bit (S + A) */
+#define R_CKCORE_PCRELIMM8BY4       2	/* disp ((S + A - P) >> 2) &0xff    */
+#define R_CKCORE_PCRELIMM11BY2      3	/* disp ((S + A - P) >> 1) & 0x7ff  */
+#define R_CKCORE_PCREL32            5	/* 32-bit rel (S + A – P)           */
+#define R_CKCORE_PCRELJSR_IMM11BY2  6	/* disp ((S + A - P) >>1) & 0x7ff   */
+#define R_CKCORE_RELATIVE           9	/* 32 bit adjust program base(B + A)*/
+#define R_CKCORE_COPY               10	/* 32 bit adjust by program base    */
+#define R_CKCORE_GLOB_DAT           11	/* off between got and sym (S)      */
+#define R_CKCORE_JUMP_SLOT          12	/* PLT entry (S) */
+#define R_CKCORE_GOTOFF             13	/* offset to GOT (S + A – GOT)      */
+#define R_CKCORE_GOTPC              14	/* PC offset to GOT (GOT + A - P)   */
+#define R_CKCORE_GOT32              15	/* 32 bit GOT entry (G) */
+#define R_CKCORE_PLT32              16	/* 32 bit PLT entry (G) */
+#define R_CKCORE_ADDRGOT            17	/* GOT entry in GLOB_DAT (GOT + G)  */
+#define R_CKCORE_ADDRPLT            18	/* PLT entry in GLOB_DAT (GOT + G)  */
+#define R_CKCORE_PCREL_IMM26BY2     19	/* ((S + A - P) >> 1) & 0x3ffffff   */
+#define R_CKCORE_PCREL_IMM16BY2     20	/* disp ((S + A - P) >> 1) & 0xffff */
+#define R_CKCORE_PCREL_IMM16BY4     21	/* disp ((S + A - P) >> 2) & 0xffff */
+#define R_CKCORE_PCREL_IMM10BY2     22	/* disp ((S + A - P) >> 1) & 0x3ff  */
+#define R_CKCORE_PCREL_IMM10BY4     23	/* disp ((S + A - P) >> 2) & 0x3ff  */
+#define R_CKCORE_ADDR_HI16          24	/* high&low 16 bit ADDR */
+                                        /* ((S + A) >> 16) & 0xffff */
+#define R_CKCORE_ADDR_LO16          25	/* (S + A) & 0xffff */
+#define R_CKCORE_GOTPC_HI16         26	/* high&low 16 bit GOTPC */
+                                        /* ((GOT + A - P) >> 16) & 0xffff */
+#define R_CKCORE_GOTPC_LO16         27	/* (GOT + A – P) & 0xffff */
+#define R_CKCORE_GOTOFF_HI16        28	/* high&low 16 bit GOTOFF */
+                                        /* ((S + A - GOT) >> 16) & 0xffff */
+#define R_CKCORE_GOTOFF_LO16        29	/* (S + A - GOT) & 0xffff */
+#define R_CKCORE_GOT12              30	/* 12 bit disp GOT entry (G) */
+#define R_CKCORE_GOT_HI16           31	/* high&low 16 bit GOT */
+                                        /* (G >> 16) & 0xffff */
+#define R_CKCORE_GOT_LO16           32	/* (G & 0xffff) */
+#define R_CKCORE_PLT12              33	/* 12 bit disp PLT entry (G) */
+#define R_CKCORE_PLT_HI16           34	/* high&low 16 bit PLT */
+                                        /* (G >> 16) & 0xffff */
+#define R_CKCORE_PLT_LO16           35	/* G & 0xffff */
+#define R_CKCORE_ADDRGOT_HI16       36	/* high&low 16 bit ADDRGOT */
+                                        /* (GOT + G * 4)& 0xffff */
+#define R_CKCORE_ADDRGOT_LO16       37	/* (GOT + G * 4) & 0xffff */
+#define R_CKCORE_ADDRPLT_HI16       38	/* high&low 16 bit ADDRPLT */
+                                        /* ((GOT + G * 4) >> 16) & 0xFFFF */
+#define R_CKCORE_ADDRPLT_LO16       39	/* (GOT+G*4) & 0xffff */
+#define R_CKCORE_PCREL_JSR_IMM26BY2 40	/* disp ((S+A-P) >>1) &x3ffffff */
+#define R_CKCORE_TOFFSET_LO16       41	/* (S+A-BTEXT) & 0xffff */
+#define R_CKCORE_DOFFSET_LO16       42	/* (S+A-BTEXT) & 0xffff */
+#define R_CKCORE_PCREL_IMM18BY2     43	/* disp ((S+A-P) >>1) &0x3ffff */
+#define R_CKCORE_DOFFSET_IMM18      44	/* disp (S+A-BDATA)&0x3ffff */
+#define R_CKCORE_DOFFSET_IMM18BY2   45	/* disp ((S+A-BDATA)>>1)&0x3ffff */
+#define R_CKCORE_DOFFSET_IMM18BY4   46	/* disp ((S+A-BDATA)>>2)&0x3ffff */
+#define R_CKCORE_GOT_IMM18BY4       48	/* disp (G >> 2) */
+#define R_CKCORE_PLT_IMM18BY4       49	/* disp (G >> 2) */
+#define R_CKCORE_PCREL_IMM7BY4      50	/* disp ((S+A-P) >>2) & 0x7f */
+#define R_CKCORE_TLS_LE32           51  /* 32 bit offset to TLS block */
+#define R_CKCORE_TLS_IE32           52
+#define R_CKCORE_TLS_GD32           53
+#define R_CKCORE_TLS_LDM32          54
+#define R_CKCORE_TLS_LDO32          55
+#define R_CKCORE_TLS_DTPMOD32       56
+#define R_CKCORE_TLS_DTPOFF32       57
+#define R_CKCORE_TLS_TPOFF32        58
+
 /* IA-64 specific declarations.  */
 
 /* Processor specific flags for the Ehdr e_flags field.  */
diff --git a/sysdeps/csky/dl-machine.h b/sysdeps/csky/dl-machine.h
new file mode 100644
index 0000000..b11b210
--- /dev/null
+++ b/sysdeps/csky/dl-machine.h
@@ -0,0 +1,471 @@ 
+/* Machine-dependent ELF dynamic relocation inline functions.  C-SKY version.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef dl_machine_h
+#define dl_machine_h
+
+#define ELF_MACHINE_NAME "csky"
+
+#include <sys/param.h>
+#include <sysdep.h>
+#include <dl-tls.h>
+
+/* Return nonzero iff ELF header is compatible with the running host.  */
+static inline int
+elf_machine_matches_host (const Elf32_Ehdr *ehdr)
+{
+#ifndef  __CSKYABIV2__
+  return ehdr->e_machine == EM_RCE;
+#else
+  return ehdr->e_machine == EM_CSKY;
+#endif
+}
+
+/* Return the link-time address of _DYNAMIC.
+   This must be inlined in a function which uses global data.  */
+static inline Elf32_Addr
+elf_machine_dynamic (void)
+{
+  register Elf32_Addr *got __asm__ ("gb");    /* need modify */
+  return *got;
+}
+
+/* Return the run-time load address ,of the shared object.  */
+static inline Elf32_Addr
+elf_machine_load_address (void)
+{
+#ifdef __CSKYABIV2__
+  extern Elf32_Addr __dl_start (void *) asm ("_dl_start");
+  Elf32_Addr got_addr = (Elf32_Addr) &__dl_start;
+  Elf32_Addr pcrel_addr;
+  asm  ("grs %0,_dl_start\n" : "=r" (pcrel_addr));
+#else
+  extern Elf32_Addr __start_flag (void *) asm ("start_flag");
+  Elf32_Addr got_addr = (Elf32_Addr) &__start_flag;
+  Elf32_Addr pcrel_addr;
+  asm  ("subi sp,8\n"		\
+	"stw lr,(sp,0)\n"	\
+	"bsr start_flag\n"	\
+	"start_flag:"		\
+	"mov  %0, lr\n"		\
+	"ldw lr,(sp,0)\n" 	\
+	"addi sp,8\n"		\
+	: "=r" (pcrel_addr));
+#endif
+  return pcrel_addr - got_addr;
+}
+
+
+/* Set up the loaded object described by L so its unrelocated PLT
+   entries will jump to the on-demand fixup code in dl-runtime.c.  */
+
+static inline int __attribute__ ((always_inline))
+elf_machine_runtime_setup (struct link_map *l, int lazy, int profile)
+{
+  Elf32_Addr *got;
+  extern void _dl_runtime_resolve (Elf32_Word);
+  extern void _dl_runtime_profile (Elf32_Word);
+
+  if (l->l_info[DT_JMPREL] && lazy)
+    {
+      /* The GOT entries for functions in the PLT have not yet been
+	 filled in.  Their initial contents will arrange when called
+	 to push an offset into the .rela.plt section, push
+	 _GLOBAL_OFFSET_TABLE_[1], and then jump to
+	 _GLOBAL_OFFSET_TABLE_[2].  */
+      got = (Elf32_Addr *) D_PTR (l, l_info[DT_PLTGOT]);
+
+      if (got[1])
+	l->l_mach.plt = got[1] + l->l_addr;
+      got[1] = (Elf32_Addr) l;	/* Identify this shared object.  */
+
+      /* The got[2] entry contains the address of a function which gets
+	 called to get the address of a so far unresolved function and
+	 jump to it.  The profiling extension of the dynamic linker allows
+	 to intercept the calls to collect information.  In this case we
+	 don't store the address in the GOT so that all future calls also
+	 end in this function.  */
+	got[2] = (Elf32_Addr) &_dl_runtime_resolve;
+    }
+  return lazy;
+}
+
+/* Mask identifying addresses reserved for the user program,
+   where the dynamic linker should not map anything.  */
+#define ELF_MACHINE_USER_ADDRESS_MASK	0x80000000UL
+
+/* Initial entry point code for the dynamic linker.
+   The C function `_dl_start' is the real entry point;
+   its return value is the user program's entry point.  */
+#ifdef __CSKYABIV2__
+#define RTLD_START asm ("\
+.text\n\
+.globl _start\n\
+.type _start, @function\n\
+.globl _dl_start_user\n\
+.type _dl_start_user, @function\n\
+_start:\n\
+        grs	gb, .Lgetpc1\n\
+.Lgetpc1:\n\
+	lrw	t0, .Lgetpc1@GOTPC\n\
+        addu	gb, t0\n\
+        mov     a0, sp\n\
+        lrw     t1, _dl_start@GOTOFF\n\
+        addu    t1, gb\n\
+        jsr     t1\n\
+_dl_start_user:\n\
+        /* get _dl_skip_args */    \n\
+	lrw	r11, _dl_skip_args@GOTOFF\n\
+	addu    r11, gb\n\
+	ldw     r11, (r11, 0)\n\
+        /* store program entry address in r11 */ \n\
+        mov     r10, a0\n\
+        /* Get argc */\n\
+        ldw     a1, (sp, 0)\n\
+        /* Get **argv */\n\
+        mov     a2, sp\n\
+        addi    a2, 4\n\
+        cmpnei  r11, 0\n\
+        bt      .L_fixup_stack\n\
+.L_done_fixup:\n\
+        mov 	a3, a1\n\
+        lsli 	a3, 2\n\
+        add     a3, a2\n\
+        addi 	a3, 4\n\
+        lrw     a0, _rtld_local@GOTOFF\n\
+        addu 	a0, gb\n\
+        ldw     a0, (a0, 0)\n\
+        lrw     t1, _dl_init@PLT\n\
+        addu    t1, gb\n\
+        ldw	t1, (t1)\n\
+        jsr     t1\n\
+        lrw     a0, _dl_fini@GOTOFF\n\
+        addu 	a0, gb\n\
+        jmp 	r10\n\
+.L_fixup_stack:\n\
+        subu    a1, r11\n\
+        lsli    r11, 2\n\
+        addu    sp, r11\n\
+        stw     a1, (sp, 0)\n\
+        mov     a2, sp\n\
+        addi    a2, 4\n\
+        lrw     a3, _dl_argv@GOTOFF\n\
+        addu    a3, gb\n\
+        stw     a2, (a3, 0)\n\
+        br      .L_done_fixup\n\
+");
+#else
+#define RTLD_START asm ("\
+.text\n\
+.globl _start\n\
+.type _start, @function\n\
+.globl _dl_start_user\n\
+.type _dl_start_user, @function\n\
+_start:\n\
+        bsr     .Lgetpc1\n\
+.Lgetpc1:\n\
+        lrw     gb, .Lgetpc1@GOTPC\n\
+        addu    gb, lr\n\
+        mov     a0, sp\n\
+        lrw     r7, _dl_start@GOTOFF\n\
+        addu    r7, gb\n\
+        jsr     r7\n\
+_dl_start_user:\n\
+        /* get _dl_skip_args */    \n\
+        lrw     r8, _dl_skip_args@GOTOFF\n\
+        addu    r8, gb\n\
+        ldw     r8, (r8, 0)\n\
+        /* store program entry address in r11 */ \n\
+        mov     r11, a0\n\
+        /* Get argc */\n\
+        ldw     a1, (sp, 0)\n\
+        /* Get **argv */\n\
+        mov     a2, sp\n\
+        addi    a2, 4\n\
+        cmpnei  r8, 0\n\
+        bt      .L_fixup_stack\n\
+.L_done_fixup:\n\
+        mov     a3, a1\n\
+        lsli    a3, 2\n\
+        addu    a3, a2\n\
+        addi    a3, 4\n\
+        lrw     a0, _rtld_local@GOTOFF\n\
+        addu    a0, gb\n\
+        ldw     a0, (a0, 0)\n\
+        lrw     r7, _dl_init@PLT\n\
+        addu    r7, gb\n\
+        ldw     r7, (r7)\n\
+        jsr     r7\n\
+        lrw     a0, _dl_fini@GOTOFF\n\
+        addu    a0, gb\n\
+        jmp     r11\n\
+.L_fixup_stack:\n\
+        subu    a1, r8\n\
+        stw     a1, (sp, 0)\n\
+        mov     a3, a2\n\
+        lsli    r8, 2\n\
+        addu    r8, a2\n\
+1:      ldw     r10, (r8, 0)\n\
+        stw     r10, (a3, 0)\n\
+        addi    r8, 4\n\
+        addi    a3, 4\n\
+        cmpnei  r10, 0\n\
+        bt      1b\n\
+1:      ldw     r10, (r8, 0)\n\
+        stw     r10, (a3, 0)\n\
+        addi    r8, 4\n\
+        addi    a3, 4\n\
+        cmpnei  r10, 0\n\
+        bt      1b\n\
+        subi    r8, 4\n\
+1:      ldw     a0, (r8, 0)\n\
+        cmpnei  a0, 0\n\
+        ldw     r10,(r8, 4)\n\
+        stw     a0, (a3, 0)\n\
+        stw     r10, (a3, 4)\n\
+        addi    a3, 8\n\
+        addi    r8, 8\n\
+        ldw     a0, (r8, 0)\n\
+        ldw     r10,(r8, 4)\n\
+        stw     a0, (a3, 0)\n\
+        stw     r10, (a3, 4)\n\
+        addi    a3, 8\n\
+        addi    r8, 8\n\
+        ldw     a0, (r8, 0)\n\
+        ldw     r10,(r8, 4)\n\
+        stw     a0, (a3, 0)\n\
+        stw     r10, (a3, 4)\n\
+        addi    a3, 8\n\
+        addi    r8, 8\n\
+        bt      1b\n\
+        lrw     a3, _dl_argv@GOTOFF\n\
+        addu    a3, gb\n\
+        stw     a2, (a3, 0)\n\
+        br      .L_done_fixup\n\
+");
+#endif
+
+/* ELF_RTYPE_CLASS_PLT iff TYPE describes relocation of a PLT entry or
+   TLS variable, so undefined references should not be allowed to
+   define the value.
+   ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one
+   of the main executable's symbols, as for a COPY reloc.  */
+#ifndef RTLD_BOOTSTRAP
+# define elf_machine_type_class(type) \
+  ((((type) == R_CKCORE_JUMP_SLOT || (type) == R_CKCORE_TLS_DTPMOD32          \
+     || (type) == R_CKCORE_TLS_DTPOFF32 || (type) == R_CKCORE_TLS_TPOFF32)    \
+    * ELF_RTYPE_CLASS_PLT)                                              \
+   | (((type) == R_CKCORE_COPY) * ELF_RTYPE_CLASS_COPY))
+#else
+#define elf_machine_type_class(type) \
+  ((((type) == R_CKCORE_JUMP_SLOT	     \
+   | (((type) == R_CKCORE_COPY) * ELF_RTYPE_CLASS_COPY))
+#endif
+
+/* A reloc type used for ld.so cmdline arg lookups to reject PLT entries.  */
+#define ELF_MACHINE_JMP_SLOT	R_CKCORE_JUMP_SLOT
+
+/* The csky never uses Elf32_Rel relocations.  */
+#define ELF_MACHINE_NO_REL 1
+#define ELF_MACHINE_NO_RELA 0
+
+/* We define an initialization functions.  This is called very early in
+   _dl_sysdep_start.  */
+#define DL_PLATFORM_INIT dl_platform_init ()
+
+static inline void __attribute__ ((unused))
+dl_platform_init (void)
+{
+  if (GLRO(dl_platform) != NULL && *GLRO(dl_platform) == '\0')
+    /* Avoid an empty string which would disturb us.  */
+    GLRO(dl_platform) = NULL;
+}
+
+static inline Elf32_Addr
+elf_machine_fixup_plt (struct link_map *map, lookup_t t,
+                       const ElfW(Sym) *refsym, const ElfW(Sym) *sym,
+                       const Elf32_Rela *reloc,
+                       Elf32_Addr *reloc_addr, Elf32_Addr value)
+{
+  return *reloc_addr = value;
+}
+
+/* Return the final value of a plt relocation.  On the csky the JMP_SLOT
+   relocation ignores the addend.  */
+static inline Elf32_Addr
+elf_machine_plt_value (struct link_map *map, const Elf32_Rela *reloc,
+		       Elf32_Addr value)
+{
+  return value;
+}
+
+/* Names of the architecture-specific auditing callback functions.  */
+#define ARCH_LA_PLTENTER csky_gnu_pltenter
+#define ARCH_LA_PLTEXIT csky_gnu_pltexit
+
+#endif /* !dl_machine_h */
+#ifdef RESOLVE_MAP
+
+/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
+   MAP is the object containing the reloc.  */
+
+auto inline void __attribute__ ((unused, always_inline))
+elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
+		  const Elf32_Sym *sym, const struct r_found_version *version,
+		  void *const reloc_addr_arg, int skip_ifunc)
+{
+  Elf32_Addr *const reloc_addr = reloc_addr_arg;
+  const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
+  unsigned short __attribute__((unused)) *opcode16_addr;
+  Elf32_Addr __attribute__((unused)) insn_opcode = 0x0;
+
+  if (__builtin_expect (r_type == R_CKCORE_RELATIVE, 0))
+    *reloc_addr = map->l_addr + reloc->r_addend;
+  else
+    {
+      const Elf32_Sym *const refsym = sym;
+      struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
+      Elf32_Addr value = sym == NULL ? 0 : sym_map->l_addr + sym->st_value;
+      opcode16_addr = (unsigned short *)reloc_addr;
+
+      switch (r_type)
+	{
+	case R_CKCORE_COPY:
+	  if (sym == NULL)
+	    /* This can happen in trace mode if an object could not be
+	       found.  */
+	    break;
+	  if (sym->st_size > refsym->st_size
+	      || (sym->st_size < refsym->st_size && GLRO(dl_verbose)))
+	    {
+	      const char *strtab;
+
+	      strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
+	      _dl_error_printf ("\
+%s: Symbol `%s' has different size in shared object, consider re-linking\n",
+				rtld_progname ?: "<program name unknown>",
+				strtab + refsym->st_name);
+	    }
+	  memcpy (reloc_addr_arg, (void *) value,
+		  MIN (sym->st_size, refsym->st_size));
+	  break;
+	case R_CKCORE_GLOB_DAT:
+	case R_CKCORE_JUMP_SLOT:
+	  *reloc_addr = value;
+	  break;
+	case R_CKCORE_ADDR32:
+	  *reloc_addr = value + reloc->r_addend;
+	  break;
+	case R_CKCORE_PCREL32:
+	  *reloc_addr = value + reloc->r_addend - (Elf32_Addr) reloc_addr;
+	  break;
+#if defined(__CK810__) || defined(__CK807__)
+    case R_CKCORE_ADDR_HI16:
+      insn_opcode = (*opcode16_addr << 16) | (*(opcode16_addr + 1));
+      insn_opcode = (insn_opcode & 0xffff0000)
+                        | (((value + reloc->r_addend) >> 16) & 0xffff);
+      *(opcode16_addr++) = (unsigned short)(insn_opcode >> 16);
+      *opcode16_addr = (unsigned short)(insn_opcode & 0xffff);
+      break;
+    case R_CKCORE_ADDR_LO16:
+      insn_opcode = (*opcode16_addr << 16) | (*(opcode16_addr + 1));
+      insn_opcode = (insn_opcode & 0xffff0000)
+                        | ((value + reloc->r_addend) & 0xffff);
+       *(opcode16_addr++) = (unsigned short)(insn_opcode >> 16);
+       *opcode16_addr = (unsigned short)(insn_opcode & 0xffff);
+       break;
+    case R_CKCORE_PCREL_IMM26BY2:
+    {
+      unsigned int offset = ((value + reloc->r_addend -
+                              (unsigned int)reloc_addr) >> 1);
+      insn_opcode = (*opcode16_addr << 16) | (*(opcode16_addr + 1));
+      if (offset > 0x3ffffff){
+        const char *strtab;
+        strtab = (const void *) D_PTR (map, l_info[DT_STRTAB]);
+
+        _dl_error_printf ("\
+%s:The reloc R_CKCORE_PCREL_IMM26BY2 cannot reach the symbol '%s'.\n",
+          rtld_progname ?: "<program name unknown>",
+          strtab + refsym->st_name);
+        break;
+      }
+      insn_opcode = (insn_opcode & ~0x3ffffff) | offset;
+      *(opcode16_addr++) = (unsigned short)(insn_opcode >> 16);
+      *opcode16_addr = (unsigned short)(insn_opcode & 0xffff);
+      break;
+    }
+    case R_CKCORE_PCREL_JSR_IMM26BY2:
+      break;
+#endif
+#ifndef RTLD_BOOTSTRAP
+	case R_CKCORE_TLS_DTPMOD32:
+        /* Get the information from the link map returned by the
+           resolv function.  */
+	  if (sym_map != NULL)
+	    *reloc_addr = sym_map->l_tls_modid;
+	  break;
+	case R_CKCORE_TLS_DTPOFF32:
+	  if (sym != NULL)
+	    *reloc_addr =(sym == NULL ? 0 : sym->st_value) + reloc->r_addend;
+	  break;
+	case R_CKCORE_TLS_TPOFF32:
+	  if (sym != NULL)
+	    {
+	      CHECK_STATIC_TLS (map, sym_map);
+	      *reloc_addr = (sym->st_value + sym_map->l_tls_offset
+                             + reloc->r_addend);
+	    }
+	  break;
+#endif /* !RTLD_BOOTSTRAP */
+	case R_CKCORE_NONE:		/* Alright, Wilbur.  */
+	  break;
+	default:
+	  break;
+	}
+    }
+}
+
+auto inline void __attribute__ ((unused, always_inline))
+elf_machine_rela_relative (Elf32_Addr l_addr, const Elf32_Rela *reloc,
+			   void *const reloc_addr_arg)
+{
+  Elf32_Addr *const reloc_addr = reloc_addr_arg;
+  *reloc_addr = l_addr + reloc->r_addend;
+}
+
+auto inline void __attribute__ ((unused, always_inline))
+elf_machine_lazy_rel (struct link_map *map,
+		      Elf32_Addr l_addr, const Elf32_Rela *reloc,
+		      int skip_ifunc)
+{
+  Elf32_Addr *const reloc_addr = (void *) (l_addr + reloc->r_offset);
+  const unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
+  if (ELF32_R_TYPE (reloc->r_info) == R_CKCORE_JUMP_SLOT)
+  {
+  /* Check for unexpected PLT reloc type.  */
+    if (__builtin_expect (r_type == R_CKCORE_JUMP_SLOT, 1))
+      {
+        if (__builtin_expect (map->l_mach.plt, 0) == 0)
+          *reloc_addr = l_addr + reloc->r_addend;
+        else
+          *reloc_addr = map->l_mach.plt;
+      }
+  }
+}
+
+#endif /* RESOLVE_MAP */
diff --git a/sysdeps/csky/dl-procinfo.c b/sysdeps/csky/dl-procinfo.c
new file mode 100644
index 0000000..b0d0054
--- /dev/null
+++ b/sysdeps/csky/dl-procinfo.c
@@ -0,0 +1,62 @@ 
+/* Data for C-SKY version of processor capability information.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* This information must be kept in sync with the _DL_PLATFORM_COUNT
+   definitions in procinfo.h.
+
+   If anything should be added here check whether the size of each string
+   is still ok with the given array size.
+
+   All the #ifdefs in the definitions are quite irritating but
+   necessary if we want to avoid duplicating the information.  There
+   are three different modes:
+
+   - PROCINFO_DECL is defined.  This means we are only interested in
+     declarations.
+
+   - PROCINFO_DECL is not defined:
+
+     + if SHARED is defined the file is included in an array
+       initializer.  The .element = { ... } syntax is needed.
+
+     + if SHARED is not defined a normal array initialization is
+       needed.
+  */
+
+#ifndef PROCINFO_CLASS
+#define PROCINFO_CLASS
+#endif
+
+#if !defined PROCINFO_DECL && defined SHARED
+  ._dl_csky_platforms
+#else
+PROCINFO_CLASS const char _dl_csky_platforms[4][6]
+#endif
+#ifndef PROCINFO_DECL
+= {
+    "ck610", "ck807", "ck810", "ck860"
+  }
+#endif
+#if !defined SHARED || defined PROCINFO_DECL
+;
+#else
+,
+#endif
+
+#undef PROCINFO_DECL
+#undef PROCINFO_CLASS
diff --git a/sysdeps/csky/dl-procinfo.h b/sysdeps/csky/dl-procinfo.h
new file mode 100644
index 0000000..4e7abe7
--- /dev/null
+++ b/sysdeps/csky/dl-procinfo.h
@@ -0,0 +1,59 @@ 
+/* C-SKY version of processor capability information handling macros.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+
+#ifndef _DL_PROCINFO_H
+#define _DL_PROCINFO_H	1
+
+#include <ldsodefs.h>
+
+/* Mask to filter out platforms.  */
+#define _DL_HWCAP_PLATFORM    (-1ULL)
+
+#define _DL_PLATFORMS_COUNT   4
+
+static inline int
+__attribute__ ((unused, always_inline))
+_dl_string_platform (const char *str)
+{
+  int i;
+
+  if (str != NULL)
+    for (i = 0; i < _DL_PLATFORMS_COUNT; ++i)
+      {
+        if (strcmp (str, GLRO(dl_csky_platforms)[i]) == 0)
+          return i;
+      }
+  return -1;
+};
+
+/* We cannot provide a general printing function.  */
+#define _dl_procinfo(word, val) -1
+
+/* There are no hardware capabilities defined.  */
+#define _dl_hwcap_string(idx) ""
+
+/* By default there is no important hardware capability.  */
+#define HWCAP_IMPORTANT (0)
+
+/* We don't have any hardware capabilities.  */
+#define _DL_HWCAP_COUNT	0
+
+#define _dl_string_hwcap(str) (-1)
+
+#endif /* dl-procinfo.h */
diff --git a/sysdeps/csky/dl-sysdep.h b/sysdeps/csky/dl-sysdep.h
new file mode 100644
index 0000000..7b3ab87
--- /dev/null
+++ b/sysdeps/csky/dl-sysdep.h
@@ -0,0 +1,23 @@ 
+/* System-specific settings for dynamic linker code.  Alpha version.
+  Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include_next <dl-sysdep.h>
+
+/* _dl_argv cannot be attribute_relro, because _dl_start_user
+   might write into it after _dl_start returns.  */
+#define DL_ARGV_NOT_RELRO 1
diff --git a/sysdeps/csky/dl-tlsdesc.h b/sysdeps/csky/dl-tlsdesc.h
new file mode 100644
index 0000000..16b2bb0
--- /dev/null
+++ b/sysdeps/csky/dl-tlsdesc.h
@@ -0,0 +1,61 @@ 
+/* Thread-local storage descriptor handling in the ELF dynamic linker.
+   CSKY version.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _CSKY_DL_TLSDESC_H
+#define _CSKY_DL_TLSDESC_H 1
+
+/* Type used to represent a TLS descriptor in the GOT.  */
+struct tlsdesc
+{
+  union
+    {
+      void *pointer;
+      long value;
+    } argument;
+  ptrdiff_t (*entry)(struct tlsdesc *);
+};
+
+typedef struct dl_tls_index
+{
+  unsigned long int ti_module;
+  unsigned long int ti_offset;
+} tls_index;
+
+/* Type used as the argument in a TLS descriptor for a symbol that
+   needs dynamic TLS offsets.  */
+struct tlsdesc_dynamic_arg
+{
+  tls_index tlsinfo;
+  size_t gen_count;
+};
+
+extern ptrdiff_t attribute_hidden
+  _dl_tlsdesc_return(struct tlsdesc *),
+  _dl_tlsdesc_undefweak(struct tlsdesc *),
+  _dl_tlsdesc_resolve_hold(struct tlsdesc *),
+  _dl_tlsdesc_lazy_resolver(struct tlsdesc *);
+
+# ifdef SHARED
+extern void *_dl_make_tlsdesc_dynamic (struct link_map *map, size_t ti_offset);
+
+extern ptrdiff_t attribute_hidden
+  _dl_tlsdesc_dynamic(struct tlsdesc *);
+# endif
+
+#endif
diff --git a/sysdeps/csky/ldsodefs.h b/sysdeps/csky/ldsodefs.h
new file mode 100644
index 0000000..b002808
--- /dev/null
+++ b/sysdeps/csky/ldsodefs.h
@@ -0,0 +1,42 @@ 
+/* Run-time dynamic linker data structures for loaded ELF shared objects.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _CSKY_LDSODEFS_H
+#define _CSKY_LDSODEFS_H 1
+
+#include <elf.h>
+
+struct La_csky_regs;
+struct La_csky_retval;
+
+#define ARCH_PLTENTER_MEMBERS	\
+    Elf32_Addr (*csky_gnu_pltenter) (Elf32_Sym *, unsigned int,		      \
+					 uintptr_t *, uintptr_t *,	      \
+					 struct La_csky_regs *,		      \
+					 unsigned int *, const char *name,    \
+					 long int *framesizep);
+
+#define ARCH_PLTEXIT_MEMBERS	\
+    unsigned int (*csky_gnu_pltexit) (Elf32_Sym *, unsigned int,	       \
+					  uintptr_t *, uintptr_t *,	       \
+					  const struct La_csky_regs *,	       \
+					  struct La_csky_retval *,	       \
+					  const char *);
+
+#include_next <ldsodefs.h>
+#endif
diff --git a/sysdeps/csky/linkmap.h b/sysdeps/csky/linkmap.h
new file mode 100644
index 0000000..7c2b4a6
--- /dev/null
+++ b/sysdeps/csky/linkmap.h
@@ -0,0 +1,5 @@ 
+struct link_map_machine
+  {
+    Elf32_Addr plt; /* Address of .plt */
+    void *tlsdesc_table; /* Address of TLS descriptor hash table.  */
+  };
diff --git a/sysdeps/csky/sotruss-lib.c b/sysdeps/csky/sotruss-lib.c
new file mode 100644
index 0000000..dac947e
--- /dev/null
+++ b/sysdeps/csky/sotruss-lib.c
@@ -0,0 +1,49 @@ 
+/* Override generic sotruss-lib.c to define actual functions for CSKY.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define HAVE_ARCH_PLTENTER
+#define HAVE_ARCH_PLTEXIT
+
+#include <elf/sotruss-lib.c>
+
+ElfW(Addr)
+la_csky_gnu_pltenter (ElfW(Sym) *sym __attribute__ ((unused)),
+		      unsigned int ndx __attribute__ ((unused)),
+		      uintptr_t *refcook, uintptr_t *defcook,
+		      La_csky_regs *regs, unsigned int *flags,
+		      const char *symname, long int *framesizep)
+{
+  print_enter (refcook, defcook, symname,
+	       regs->lr_reg[0], regs->lr_reg[1], regs->lr_reg[2],
+	       *flags);
+
+  /* No need to copy anything, we will not need the parameters in any case.  */
+  *framesizep = 0;
+
+  return sym->st_value;
+}
+
+unsigned int
+la_csky_gnu_pltexit (ElfW(Sym) *sym, unsigned int ndx, uintptr_t *refcook,
+		     uintptr_t *defcook, const struct La_csky_regs *inregs,
+		     struct La_csky_retval *outregs, const char *symname)
+{
+  print_exit (refcook, defcook, symname, outregs->lrv_v0);
+
+  return 0;
+}
diff --git a/sysdeps/unix/sysv/linux/csky/ldconfig.h b/sysdeps/unix/sysv/linux/csky/ldconfig.h
new file mode 100644
index 0000000..912a868
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/ldconfig.h
@@ -0,0 +1,24 @@ 
+/* Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sysdeps/generic/ldconfig.h>
+
+#define SYSDEP_KNOWN_INTERPRETER_NAMES \
+  { "/lib/ld-linux.so.2", FLAG_ELF_LIBC6 },
+#define SYSDEP_KNOWN_LIBRARY_NAMES \
+  { "libc.so.6", FLAG_ELF_LIBC6 },	\
+  { "libm.so.6", FLAG_ELF_LIBC6 },