gdbserver/linux-loongarch-low.cc - binutils-gdb - Git at Google

 /* GNU/Linux/LoongArch specific low level interface, for the remote server
    for GDB.
    Copyright (C) 2022-2024 Free Software Foundation, Inc.

    This file is part of GDB.

    This program 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.

    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.  */

 #include "linux-low.h"
 #include "tdesc.h"
 #include "elf/common.h"
 #include "arch/loongarch.h"

 /* Linux target ops definitions for the LoongArch architecture.  */

 class loongarch_target : public linux_process_target
 {
 public:

   const regs_info *get_regs_info () override;

   int breakpoint_kind_from_pc (CORE_ADDR *pcptr) override;

   const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override;

 protected:

   void low_arch_setup () override;

   bool low_cannot_fetch_register (int regno) override;

   bool low_cannot_store_register (int regno) override;

   bool low_fetch_register (regcache *regcache, int regno) override;

   bool low_supports_breakpoints () override;

   CORE_ADDR low_get_pc (regcache *regcache) override;

   void low_set_pc (regcache *regcache, CORE_ADDR newpc) override;

   bool low_breakpoint_at (CORE_ADDR pc) override;
 };

 /* The singleton target ops object.  */

 static loongarch_target the_loongarch_target;

 bool
 loongarch_target::low_cannot_fetch_register (int regno)
 {
   gdb_assert_not_reached ("linux target op low_cannot_fetch_register "
 			  "is not implemented by the target");
 }

 bool
 loongarch_target::low_cannot_store_register (int regno)
 {
   gdb_assert_not_reached ("linux target op low_cannot_store_register "
 			  "is not implemented by the target");
 }

 /* Implementation of linux target ops method "low_arch_setup".  */

 void
 loongarch_target::low_arch_setup ()
 {
   static const char *expedite_regs[] = { "r3", "pc", NULL };
   loongarch_gdbarch_features features;
   target_desc_up tdesc;

   features.xlen = sizeof (elf_greg_t);
   tdesc = loongarch_create_target_description (features);

   if (tdesc->expedite_regs.empty ())
     {
       init_target_desc (tdesc.get (), expedite_regs);
       gdb_assert (!tdesc->expedite_regs.empty ());
     }
   current_process ()->tdesc = tdesc.release ();
 }

 /* Collect GPRs from REGCACHE into BUF.  */

 static void
 loongarch_fill_gregset (struct regcache *regcache, void *buf)
 {
   elf_gregset_t *regset = (elf_gregset_t *) buf;
   int i;

   for (i = 1; i < 32; i++)
     collect_register (regcache, i, *regset + i);
   collect_register (regcache, LOONGARCH_ORIG_A0_REGNUM, *regset + LOONGARCH_ORIG_A0_REGNUM);
   collect_register (regcache, LOONGARCH_PC_REGNUM, *regset + LOONGARCH_PC_REGNUM);
   collect_register (regcache, LOONGARCH_BADV_REGNUM, *regset + LOONGARCH_BADV_REGNUM);
 }

 /* Supply GPRs from BUF into REGCACHE.  */

 static void
 loongarch_store_gregset (struct regcache *regcache, const void *buf)
 {
   const elf_gregset_t *regset = (const elf_gregset_t *) buf;
   int i;

   supply_register_zeroed (regcache, 0);
   for (i = 1; i < 32; i++)
     supply_register (regcache, i, *regset + i);
   supply_register (regcache, LOONGARCH_ORIG_A0_REGNUM, *regset + LOONGARCH_ORIG_A0_REGNUM);
   supply_register (regcache, LOONGARCH_PC_REGNUM, *regset + LOONGARCH_PC_REGNUM);
   supply_register (regcache, LOONGARCH_BADV_REGNUM, *regset + LOONGARCH_BADV_REGNUM);
 }

 /* Collect FPRs from REGCACHE into BUF.  */

 static void
 loongarch_fill_fpregset (struct regcache *regcache, void *buf)
 {
   gdb_byte *regbuf = nullptr;
   int fprsize = register_size (regcache->tdesc, LOONGARCH_FIRST_FP_REGNUM);
   int fccsize = register_size (regcache->tdesc, LOONGARCH_FIRST_FCC_REGNUM);

   for (int i = 0; i < LOONGARCH_LINUX_NUM_FPREGSET; i++)
     {
       regbuf = (gdb_byte *)buf + fprsize * i;
       collect_register (regcache, LOONGARCH_FIRST_FP_REGNUM + i, regbuf);
     }

   for (int i = 0; i < LOONGARCH_LINUX_NUM_FCC; i++)
     {
       regbuf = (gdb_byte *)buf + fprsize * LOONGARCH_LINUX_NUM_FPREGSET +
 	fccsize * i;
       collect_register (regcache, LOONGARCH_FIRST_FCC_REGNUM + i, regbuf);
     }

   regbuf = (gdb_byte *)buf + fprsize * LOONGARCH_LINUX_NUM_FPREGSET +
     fccsize * LOONGARCH_LINUX_NUM_FCC;
   collect_register (regcache, LOONGARCH_FCSR_REGNUM, regbuf);
 }

 /* Supply FPRs from BUF into REGCACHE.  */

 static void
 loongarch_store_fpregset (struct regcache *regcache, const void *buf)
 {
   const gdb_byte *regbuf = nullptr;
   int fprsize = register_size (regcache->tdesc, LOONGARCH_FIRST_FP_REGNUM);
   int fccsize = register_size (regcache->tdesc, LOONGARCH_FIRST_FCC_REGNUM);

   for (int i = 0; i < LOONGARCH_LINUX_NUM_FPREGSET; i++)
     {
       regbuf = (const gdb_byte *)buf + fprsize * i;
       supply_register (regcache, LOONGARCH_FIRST_FP_REGNUM + i, regbuf);
     }

   for (int i = 0; i < LOONGARCH_LINUX_NUM_FCC; i++)
     {
       regbuf = (const gdb_byte *)buf + fprsize * LOONGARCH_LINUX_NUM_FPREGSET +
 	fccsize * i;
       supply_register (regcache, LOONGARCH_FIRST_FCC_REGNUM + i, regbuf);
     }

   regbuf = (const gdb_byte *)buf + fprsize * LOONGARCH_LINUX_NUM_FPREGSET +
     fccsize * LOONGARCH_LINUX_NUM_FCC;
   supply_register (regcache, LOONGARCH_FCSR_REGNUM, regbuf);
 }

 /* Collect lsx regs from REGCACHE into BUF.  */

 static void
 loongarch_fill_lsxregset (struct regcache *regcache, void *buf)
 {
   elf_lsxregset_t *regset = (elf_lsxregset_t *) buf;
   int i;

   for (i = 0; i < LOONGARCH_LINUX_NUM_LSXREGSET; i++)
     collect_register (regcache, LOONGARCH_FIRST_LSX_REGNUM + i, *regset + i);
 }

 /* Supply lsx regs from BUF into REGCACHE.  */

 static void
 loongarch_store_lsxregset (struct regcache *regcache, const void *buf)
 {
   const elf_lsxregset_t *regset = (const elf_lsxregset_t *) buf;
   int i;

   for (i = 0; i < LOONGARCH_LINUX_NUM_LSXREGSET; i++)
     supply_register (regcache, LOONGARCH_FIRST_LSX_REGNUM + i, *regset + i);
 }

 /* Collect lasx regs from REGCACHE into BUF.  */

 static void
 loongarch_fill_lasxregset (struct regcache *regcache, void *buf)
 {
   elf_lasxregset_t *regset = (elf_lasxregset_t *) buf;
   int i;

   for (i = 0; i < LOONGARCH_LINUX_NUM_LASXREGSET; i++)
     collect_register (regcache, LOONGARCH_FIRST_LASX_REGNUM + i, *regset + i);
 }

 /* Supply lasx regs from BUF into REGCACHE.  */

 static void
 loongarch_store_lasxregset (struct regcache *regcache, const void *buf)
 {
   const elf_lasxregset_t *regset = (const elf_lasxregset_t *) buf;
   int i;

   for (i = 0; i < LOONGARCH_LINUX_NUM_LASXREGSET; i++)
     supply_register (regcache, LOONGARCH_FIRST_LASX_REGNUM + i, *regset + i);
 }

 /* Collect lbt regs from REGCACHE into BUF.  */

 static void
 loongarch_fill_lbtregset (struct regcache *regcache, void *buf)
 {
   gdb_byte *regbuf = (gdb_byte*)buf;
   int scrsize = register_size (regcache->tdesc, LOONGARCH_FIRST_SCR_REGNUM);
   int eflagssize = register_size (regcache->tdesc, LOONGARCH_EFLAGS_REGNUM);
   int i;

   for (i = 0; i < LOONGARCH_LINUX_NUM_SCR; i++)
     collect_register (regcache, LOONGARCH_FIRST_SCR_REGNUM + i, regbuf + scrsize * i);

   collect_register (regcache, LOONGARCH_EFLAGS_REGNUM,
 		    regbuf + LOONGARCH_LINUX_NUM_SCR * scrsize);
   collect_register (regcache, LOONGARCH_FTOP_REGNUM,
 		    regbuf + LOONGARCH_LINUX_NUM_SCR * scrsize + eflagssize);

 }

 /* Supply lbt regs from BUF into REGCACHE.  */

 static void
 loongarch_store_lbtregset (struct regcache *regcache, const void *buf)
 {

   gdb_byte *regbuf = (gdb_byte*)buf;
   int scrsize = register_size (regcache->tdesc, LOONGARCH_FIRST_SCR_REGNUM);
   int eflagssize = register_size (regcache->tdesc, LOONGARCH_EFLAGS_REGNUM);
   int i;

   for (i = 0; i < LOONGARCH_LINUX_NUM_SCR; i++)
     supply_register (regcache, LOONGARCH_FIRST_SCR_REGNUM + i, regbuf + scrsize * i);

   supply_register (regcache, LOONGARCH_EFLAGS_REGNUM,
 		    regbuf + LOONGARCH_LINUX_NUM_SCR * scrsize);
   supply_register (regcache, LOONGARCH_FTOP_REGNUM,
 		    regbuf + LOONGARCH_LINUX_NUM_SCR * scrsize + eflagssize);

 }

 /* LoongArch/Linux regsets.  */
 static struct regset_info loongarch_regsets[] = {
   { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PRSTATUS, sizeof (elf_gregset_t),
     GENERAL_REGS, loongarch_fill_gregset, loongarch_store_gregset },
   { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_FPREGSET, sizeof (elf_fpregset_t),
     FP_REGS, loongarch_fill_fpregset, loongarch_store_fpregset },
   { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_LARCH_LSX, sizeof (elf_lsxregset_t),
     OPTIONAL_REGS, loongarch_fill_lsxregset, loongarch_store_lsxregset },
   { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_LARCH_LASX, sizeof (elf_lasxregset_t),
     OPTIONAL_REGS, loongarch_fill_lasxregset, loongarch_store_lasxregset },
   { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_LARCH_LBT, LOONGARCH_LBT_REGS_SIZE,
     OPTIONAL_REGS, loongarch_fill_lbtregset, loongarch_store_lbtregset },
   NULL_REGSET
 };

 /* LoongArch/Linux regset information.  */
 static struct regsets_info loongarch_regsets_info =
   {
     loongarch_regsets, /* regsets */
     0, /* num_regsets */
     NULL, /* disabled_regsets */
   };

 /* Definition of linux_target_ops data member "regs_info".  */
 static struct regs_info loongarch_regs =
   {
     NULL, /* regset_bitmap */
     NULL, /* usrregs */
     &loongarch_regsets_info,
   };

 /* Implementation of linux target ops method "get_regs_info".  */

 const regs_info *
 loongarch_target::get_regs_info ()
 {
   return &loongarch_regs;
 }

 /* Implementation of linux target ops method "low_fetch_register".  */

 bool
 loongarch_target::low_fetch_register (regcache *regcache, int regno)
 {
   if (regno != 0)
     return false;
   supply_register_zeroed (regcache, 0);
   return true;
 }

 bool
 loongarch_target::low_supports_breakpoints ()
 {
   return true;
 }

 /* Implementation of linux target ops method "low_get_pc".  */

 CORE_ADDR
 loongarch_target::low_get_pc (regcache *regcache)
 {
   if (register_size (regcache->tdesc, 0) == 8)
     return linux_get_pc_64bit (regcache);
   else
     return linux_get_pc_32bit (regcache);
 }

 /* Implementation of linux target ops method "low_set_pc".  */

 void
 loongarch_target::low_set_pc (regcache *regcache, CORE_ADDR newpc)
 {
   if (register_size (regcache->tdesc, 0) == 8)
     linux_set_pc_64bit (regcache, newpc);
   else
     linux_set_pc_32bit (regcache, newpc);
 }

 #define loongarch_breakpoint_len 4

 /* LoongArch BRK software debug mode instruction.
    This instruction needs to match gdb/loongarch-tdep.c
    (loongarch_default_breakpoint).  */
 static const gdb_byte loongarch_breakpoint[] = {0x05, 0x00, 0x2a, 0x00};

 /* Implementation of target ops method "breakpoint_kind_from_pc".  */

 int
 loongarch_target::breakpoint_kind_from_pc (CORE_ADDR *pcptr)
 {
   return loongarch_breakpoint_len;
 }

 /* Implementation of target ops method "sw_breakpoint_from_kind".  */

 const gdb_byte *
 loongarch_target::sw_breakpoint_from_kind (int kind, int *size)
 {
   *size = loongarch_breakpoint_len;
   return (const gdb_byte *) &loongarch_breakpoint;
 }

 /* Implementation of linux target ops method "low_breakpoint_at".  */

 bool
 loongarch_target::low_breakpoint_at (CORE_ADDR pc)
 {
   gdb_byte insn[loongarch_breakpoint_len];

   read_memory (pc, (unsigned char *) &insn, loongarch_breakpoint_len);
   if (memcmp (insn, loongarch_breakpoint, loongarch_breakpoint_len) == 0)
     return true;

   return false;
 }

 /* The linux target ops object.  */

 linux_process_target *the_linux_target = &the_loongarch_target;

 /* Initialize the LoongArch/Linux target.  */

 void
 initialize_low_arch ()
 {
   initialize_regsets_info (&loongarch_regsets_info);
 }
	/* GNU/Linux/LoongArch specific low level interface, for the remote server
	for GDB.
	Copyright (C) 2022-2024 Free Software Foundation, Inc.

	This file is part of GDB.

	This program 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.

	This program 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 this program. If not, see <http://www.gnu.org/licenses/>. */

	#include "linux-low.h"
	#include "tdesc.h"
	#include "elf/common.h"
	#include "arch/loongarch.h"

	/* Linux target ops definitions for the LoongArch architecture. */

	class loongarch_target : public linux_process_target
	{
	public:

	const regs_info *get_regs_info () override;

	int breakpoint_kind_from_pc (CORE_ADDR *pcptr) override;

	const gdb_byte sw_breakpoint_from_kind (int kind, int size) override;

	protected:

	void low_arch_setup () override;

	bool low_cannot_fetch_register (int regno) override;

	bool low_cannot_store_register (int regno) override;

	bool low_fetch_register (regcache *regcache, int regno) override;

	bool low_supports_breakpoints () override;

	CORE_ADDR low_get_pc (regcache *regcache) override;

	void low_set_pc (regcache *regcache, CORE_ADDR newpc) override;

	bool low_breakpoint_at (CORE_ADDR pc) override;
	};

	/* The singleton target ops object. */

	static loongarch_target the_loongarch_target;

	bool
	loongarch_target::low_cannot_fetch_register (int regno)
	{
	gdb_assert_not_reached ("linux target op low_cannot_fetch_register "
	"is not implemented by the target");
	}

	bool
	loongarch_target::low_cannot_store_register (int regno)
	{
	gdb_assert_not_reached ("linux target op low_cannot_store_register "
	"is not implemented by the target");
	}

	/* Implementation of linux target ops method "low_arch_setup". */

	void
	loongarch_target::low_arch_setup ()
	{
	static const char *expedite_regs[] = { "r3", "pc", NULL };
	loongarch_gdbarch_features features;
	target_desc_up tdesc;

	features.xlen = sizeof (elf_greg_t);
	tdesc = loongarch_create_target_description (features);

	if (tdesc->expedite_regs.empty ())
	{
	init_target_desc (tdesc.get (), expedite_regs);
	gdb_assert (!tdesc->expedite_regs.empty ());
	}
	current_process ()->tdesc = tdesc.release ();
	}

	/* Collect GPRs from REGCACHE into BUF. */

	static void
	loongarch_fill_gregset (struct regcache regcache, void buf)
	{
	elf_gregset_t regset = (elf_gregset_t ) buf;
	int i;

	for (i = 1; i < 32; i++)
	collect_register (regcache, i, *regset + i);
	collect_register (regcache, LOONGARCH_ORIG_A0_REGNUM, *regset + LOONGARCH_ORIG_A0_REGNUM);
	collect_register (regcache, LOONGARCH_PC_REGNUM, *regset + LOONGARCH_PC_REGNUM);
	collect_register (regcache, LOONGARCH_BADV_REGNUM, *regset + LOONGARCH_BADV_REGNUM);
	}

	/* Supply GPRs from BUF into REGCACHE. */

	static void
	loongarch_store_gregset (struct regcache regcache, const void buf)
	{
	const elf_gregset_t regset = (const elf_gregset_t ) buf;
	int i;

	supply_register_zeroed (regcache, 0);
	for (i = 1; i < 32; i++)
	supply_register (regcache, i, *regset + i);
	supply_register (regcache, LOONGARCH_ORIG_A0_REGNUM, *regset + LOONGARCH_ORIG_A0_REGNUM);
	supply_register (regcache, LOONGARCH_PC_REGNUM, *regset + LOONGARCH_PC_REGNUM);
	supply_register (regcache, LOONGARCH_BADV_REGNUM, *regset + LOONGARCH_BADV_REGNUM);
	}

	/* Collect FPRs from REGCACHE into BUF. */

	static void
	loongarch_fill_fpregset (struct regcache regcache, void buf)
	{
	gdb_byte *regbuf = nullptr;
	int fprsize = register_size (regcache->tdesc, LOONGARCH_FIRST_FP_REGNUM);
	int fccsize = register_size (regcache->tdesc, LOONGARCH_FIRST_FCC_REGNUM);

	for (int i = 0; i < LOONGARCH_LINUX_NUM_FPREGSET; i++)
	{
	regbuf = (gdb_byte )buf + fprsize i;
	collect_register (regcache, LOONGARCH_FIRST_FP_REGNUM + i, regbuf);
	}

	for (int i = 0; i < LOONGARCH_LINUX_NUM_FCC; i++)
	{
	regbuf = (gdb_byte )buf + fprsize LOONGARCH_LINUX_NUM_FPREGSET +
	fccsize * i;
	collect_register (regcache, LOONGARCH_FIRST_FCC_REGNUM + i, regbuf);
	}

	regbuf = (gdb_byte )buf + fprsize LOONGARCH_LINUX_NUM_FPREGSET +
	fccsize * LOONGARCH_LINUX_NUM_FCC;
	collect_register (regcache, LOONGARCH_FCSR_REGNUM, regbuf);
	}

	/* Supply FPRs from BUF into REGCACHE. */

	static void
	loongarch_store_fpregset (struct regcache regcache, const void buf)
	{
	const gdb_byte *regbuf = nullptr;
	int fprsize = register_size (regcache->tdesc, LOONGARCH_FIRST_FP_REGNUM);
	int fccsize = register_size (regcache->tdesc, LOONGARCH_FIRST_FCC_REGNUM);

	for (int i = 0; i < LOONGARCH_LINUX_NUM_FPREGSET; i++)
	{
	regbuf = (const gdb_byte )buf + fprsize i;
	supply_register (regcache, LOONGARCH_FIRST_FP_REGNUM + i, regbuf);
	}

	for (int i = 0; i < LOONGARCH_LINUX_NUM_FCC; i++)
	{
	regbuf = (const gdb_byte )buf + fprsize LOONGARCH_LINUX_NUM_FPREGSET +
	fccsize * i;
	supply_register (regcache, LOONGARCH_FIRST_FCC_REGNUM + i, regbuf);
	}

	regbuf = (const gdb_byte )buf + fprsize LOONGARCH_LINUX_NUM_FPREGSET +
	fccsize * LOONGARCH_LINUX_NUM_FCC;
	supply_register (regcache, LOONGARCH_FCSR_REGNUM, regbuf);
	}

	/* Collect lsx regs from REGCACHE into BUF. */

	static void
	loongarch_fill_lsxregset (struct regcache regcache, void buf)
	{
	elf_lsxregset_t regset = (elf_lsxregset_t ) buf;
	int i;

	for (i = 0; i < LOONGARCH_LINUX_NUM_LSXREGSET; i++)
	collect_register (regcache, LOONGARCH_FIRST_LSX_REGNUM + i, *regset + i);
	}

	/* Supply lsx regs from BUF into REGCACHE. */

	static void
	loongarch_store_lsxregset (struct regcache regcache, const void buf)
	{
	const elf_lsxregset_t regset = (const elf_lsxregset_t ) buf;
	int i;

	for (i = 0; i < LOONGARCH_LINUX_NUM_LSXREGSET; i++)
	supply_register (regcache, LOONGARCH_FIRST_LSX_REGNUM + i, *regset + i);
	}

	/* Collect lasx regs from REGCACHE into BUF. */

	static void
	loongarch_fill_lasxregset (struct regcache regcache, void buf)
	{
	elf_lasxregset_t regset = (elf_lasxregset_t ) buf;
	int i;

	for (i = 0; i < LOONGARCH_LINUX_NUM_LASXREGSET; i++)
	collect_register (regcache, LOONGARCH_FIRST_LASX_REGNUM + i, *regset + i);
	}

	/* Supply lasx regs from BUF into REGCACHE. */

	static void
	loongarch_store_lasxregset (struct regcache regcache, const void buf)
	{
	const elf_lasxregset_t regset = (const elf_lasxregset_t ) buf;
	int i;

	for (i = 0; i < LOONGARCH_LINUX_NUM_LASXREGSET; i++)
	supply_register (regcache, LOONGARCH_FIRST_LASX_REGNUM + i, *regset + i);
	}

	/* Collect lbt regs from REGCACHE into BUF. */

	static void
	loongarch_fill_lbtregset (struct regcache regcache, void buf)
	{
	gdb_byte regbuf = (gdb_byte)buf;
	int scrsize = register_size (regcache->tdesc, LOONGARCH_FIRST_SCR_REGNUM);
	int eflagssize = register_size (regcache->tdesc, LOONGARCH_EFLAGS_REGNUM);
	int i;

	for (i = 0; i < LOONGARCH_LINUX_NUM_SCR; i++)
	collect_register (regcache, LOONGARCH_FIRST_SCR_REGNUM + i, regbuf + scrsize * i);

	collect_register (regcache, LOONGARCH_EFLAGS_REGNUM,
	regbuf + LOONGARCH_LINUX_NUM_SCR * scrsize);
	collect_register (regcache, LOONGARCH_FTOP_REGNUM,
	regbuf + LOONGARCH_LINUX_NUM_SCR * scrsize + eflagssize);

	}

	/* Supply lbt regs from BUF into REGCACHE. */

	static void
	loongarch_store_lbtregset (struct regcache regcache, const void buf)
	{

	gdb_byte regbuf = (gdb_byte)buf;
	int scrsize = register_size (regcache->tdesc, LOONGARCH_FIRST_SCR_REGNUM);
	int eflagssize = register_size (regcache->tdesc, LOONGARCH_EFLAGS_REGNUM);
	int i;

	for (i = 0; i < LOONGARCH_LINUX_NUM_SCR; i++)
	supply_register (regcache, LOONGARCH_FIRST_SCR_REGNUM + i, regbuf + scrsize * i);

	supply_register (regcache, LOONGARCH_EFLAGS_REGNUM,
	regbuf + LOONGARCH_LINUX_NUM_SCR * scrsize);
	supply_register (regcache, LOONGARCH_FTOP_REGNUM,
	regbuf + LOONGARCH_LINUX_NUM_SCR * scrsize + eflagssize);

	}

	/* LoongArch/Linux regsets. */
	static struct regset_info loongarch_regsets[] = {
	{ PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PRSTATUS, sizeof (elf_gregset_t),
	GENERAL_REGS, loongarch_fill_gregset, loongarch_store_gregset },
	{ PTRACE_GETREGSET, PTRACE_SETREGSET, NT_FPREGSET, sizeof (elf_fpregset_t),
	FP_REGS, loongarch_fill_fpregset, loongarch_store_fpregset },
	{ PTRACE_GETREGSET, PTRACE_SETREGSET, NT_LARCH_LSX, sizeof (elf_lsxregset_t),
	OPTIONAL_REGS, loongarch_fill_lsxregset, loongarch_store_lsxregset },
	{ PTRACE_GETREGSET, PTRACE_SETREGSET, NT_LARCH_LASX, sizeof (elf_lasxregset_t),
	OPTIONAL_REGS, loongarch_fill_lasxregset, loongarch_store_lasxregset },
	{ PTRACE_GETREGSET, PTRACE_SETREGSET, NT_LARCH_LBT, LOONGARCH_LBT_REGS_SIZE,
	OPTIONAL_REGS, loongarch_fill_lbtregset, loongarch_store_lbtregset },
	NULL_REGSET
	};

	/* LoongArch/Linux regset information. */
	static struct regsets_info loongarch_regsets_info =
	{
	loongarch_regsets, /* regsets */
	0, /* num_regsets */
	NULL, /* disabled_regsets */
	};

	/* Definition of linux_target_ops data member "regs_info". */
	static struct regs_info loongarch_regs =
	{
	NULL, /* regset_bitmap */
	NULL, /* usrregs */
	&loongarch_regsets_info,
	};

	/* Implementation of linux target ops method "get_regs_info". */

	const regs_info *
	loongarch_target::get_regs_info ()
	{
	return &loongarch_regs;
	}

	/* Implementation of linux target ops method "low_fetch_register". */

	bool
	loongarch_target::low_fetch_register (regcache *regcache, int regno)
	{
	if (regno != 0)
	return false;
	supply_register_zeroed (regcache, 0);
	return true;
	}

	bool
	loongarch_target::low_supports_breakpoints ()
	{
	return true;
	}

	/* Implementation of linux target ops method "low_get_pc". */

	CORE_ADDR
	loongarch_target::low_get_pc (regcache *regcache)
	{
	if (register_size (regcache->tdesc, 0) == 8)
	return linux_get_pc_64bit (regcache);
	else
	return linux_get_pc_32bit (regcache);
	}

	/* Implementation of linux target ops method "low_set_pc". */

	void
	loongarch_target::low_set_pc (regcache *regcache, CORE_ADDR newpc)
	{
	if (register_size (regcache->tdesc, 0) == 8)
	linux_set_pc_64bit (regcache, newpc);
	else
	linux_set_pc_32bit (regcache, newpc);
	}

	#define loongarch_breakpoint_len 4

	/* LoongArch BRK software debug mode instruction.
	This instruction needs to match gdb/loongarch-tdep.c
	(loongarch_default_breakpoint). */
	static const gdb_byte loongarch_breakpoint[] = {0x05, 0x00, 0x2a, 0x00};

	/* Implementation of target ops method "breakpoint_kind_from_pc". */

	int
	loongarch_target::breakpoint_kind_from_pc (CORE_ADDR *pcptr)
	{
	return loongarch_breakpoint_len;
	}

	/* Implementation of target ops method "sw_breakpoint_from_kind". */

	const gdb_byte *
	loongarch_target::sw_breakpoint_from_kind (int kind, int *size)
	{
	*size = loongarch_breakpoint_len;
	return (const gdb_byte *) &loongarch_breakpoint;
	}

	/* Implementation of linux target ops method "low_breakpoint_at". */

	bool
	loongarch_target::low_breakpoint_at (CORE_ADDR pc)
	{
	gdb_byte insn[loongarch_breakpoint_len];

	read_memory (pc, (unsigned char *) &insn, loongarch_breakpoint_len);
	if (memcmp (insn, loongarch_breakpoint, loongarch_breakpoint_len) == 0)
	return true;

	return false;
	}

	/* The linux target ops object. */

	linux_process_target *the_linux_target = &the_loongarch_target;

	/* Initialize the LoongArch/Linux target. */

	void
	initialize_low_arch ()
	{
	initialize_regsets_info (&loongarch_regsets_info);
	}