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

 /* GNU/Linux/Xtensa specific low level interface, for the remote server for GDB.
    Copyright (C) 2007-2021 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 "server.h"
 #include "linux-low.h"

 /* Linux target op definitions for the Xtensa architecture.  */

 class xtensa_target : public linux_process_target
 {
 public:

   const regs_info *get_regs_info () 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_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 xtensa_target the_xtensa_target;

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

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

 CORE_ADDR
 xtensa_target::low_get_pc (regcache *regcache)
 {
   return linux_get_pc_32bit (regcache);
 }

 void
 xtensa_target::low_set_pc (regcache *regcache, CORE_ADDR pc)
 {
   linux_set_pc_32bit (regcache, pc);
 }

 /* Defined in auto-generated file reg-xtensa.c.  */
 void init_registers_xtensa (void);
 extern const struct target_desc *tdesc_xtensa;

 #include <asm/ptrace.h>
 #include <xtensa-config.h>
 #include "arch/xtensa.h"
 #include "gdb_proc_service.h"

 #include "xtensa-xtregs.c"

 enum regnum {
 	R_PC=0,	R_PS,
 	R_LBEG,	R_LEND,	R_LCOUNT,
 	R_SAR,
 	R_WS, R_WB,
 	R_THREADPTR,
 	R_A0 = 64
 };

 static void
 xtensa_fill_gregset (struct regcache *regcache, void *buf)
 {
   elf_greg_t* rset = (elf_greg_t*)buf;
   const struct target_desc *tdesc = regcache->tdesc;
   int ar0_regnum;
   char *ptr;
   int i;

   /* Take care of AR registers.  */

   ar0_regnum = find_regno (tdesc, "ar0");
   ptr = (char*)&rset[R_A0];

   for (i = ar0_regnum; i < ar0_regnum + XCHAL_NUM_AREGS; i++)
     {
       collect_register (regcache, i, ptr);
       ptr += register_size (tdesc, i);
     }

   if (XSHAL_ABI == XTHAL_ABI_CALL0)
     {
       int a0_regnum = find_regno (tdesc, "a0");
       ptr = (char *) &rset[R_A0 + 4 * rset[R_WB]];

       for (i = a0_regnum; i < a0_regnum + C0_NREGS; i++)
 	{
 	  if ((4 * rset[R_WB] + i - a0_regnum) == XCHAL_NUM_AREGS)
 	    ptr = (char *) &rset[R_A0];
 	  collect_register (regcache, i, ptr);
 	  ptr += register_size (tdesc, i);
 	}
     }

   /* Loop registers, if hardware has it.  */

 #if XCHAL_HAVE_LOOPS
   collect_register_by_name (regcache, "lbeg", (char*)&rset[R_LBEG]);
   collect_register_by_name (regcache, "lend", (char*)&rset[R_LEND]);
   collect_register_by_name (regcache, "lcount", (char*)&rset[R_LCOUNT]);
 #endif

   collect_register_by_name (regcache, "sar", (char*)&rset[R_SAR]);
   collect_register_by_name (regcache, "pc", (char*)&rset[R_PC]);
   collect_register_by_name (regcache, "ps", (char*)&rset[R_PS]);
   collect_register_by_name (regcache, "windowbase", (char*)&rset[R_WB]);
   collect_register_by_name (regcache, "windowstart", (char*)&rset[R_WS]);

 #if XCHAL_HAVE_THREADPTR
   collect_register_by_name (regcache, "threadptr",
 			    (char *) &rset[R_THREADPTR]);
 #endif
 }

 static void
 xtensa_store_gregset (struct regcache *regcache, const void *buf)
 {
   const elf_greg_t* rset = (const elf_greg_t*)buf;
   const struct target_desc *tdesc = regcache->tdesc;
   int ar0_regnum;
   char *ptr;
   int i;

   /* Take care of AR registers.  */

   ar0_regnum = find_regno (tdesc, "ar0");
   ptr = (char *)&rset[R_A0];

   for (i = ar0_regnum; i < ar0_regnum + XCHAL_NUM_AREGS; i++)
     {
       supply_register (regcache, i, ptr);
       ptr += register_size (tdesc, i);
     }

   if (XSHAL_ABI == XTHAL_ABI_CALL0)
     {
       int a0_regnum = find_regno (tdesc, "a0");
       ptr = (char *) &rset[R_A0 + (4 * rset[R_WB]) % XCHAL_NUM_AREGS];

       for (i = a0_regnum; i < a0_regnum + C0_NREGS; i++)
 	{
 	  if ((4 * rset[R_WB] + i - a0_regnum) == XCHAL_NUM_AREGS)
 	    ptr = (char *) &rset[R_A0];
 	  supply_register (regcache, i, ptr);
 	  ptr += register_size (tdesc, i);
 	}
     }

   /* Loop registers, if hardware has it.  */

 #if XCHAL_HAVE_LOOPS
   supply_register_by_name (regcache, "lbeg", (char*)&rset[R_LBEG]);
   supply_register_by_name (regcache, "lend", (char*)&rset[R_LEND]);
   supply_register_by_name (regcache, "lcount", (char*)&rset[R_LCOUNT]);
 #endif

   supply_register_by_name (regcache, "sar", (char*)&rset[R_SAR]);
   supply_register_by_name (regcache, "pc", (char*)&rset[R_PC]);
   supply_register_by_name (regcache, "ps", (char*)&rset[R_PS]);
   supply_register_by_name (regcache, "windowbase", (char*)&rset[R_WB]);
   supply_register_by_name (regcache, "windowstart", (char*)&rset[R_WS]);

 #if XCHAL_HAVE_THREADPTR
   supply_register_by_name (regcache, "threadptr",
 			   (char *) &rset[R_THREADPTR]);
 #endif
 }

 /* Xtensa GNU/Linux PTRACE interface includes extended register set.  */

 static void
 xtensa_fill_xtregset (struct regcache *regcache, void *buf)
 {
   const xtensa_regtable_t *ptr;

   for (ptr = xtensa_regmap_table; ptr->name; ptr++)
     {
       collect_register_by_name (regcache, ptr->name,
 				(char*)buf + ptr->ptrace_offset);
     }
 }

 static void
 xtensa_store_xtregset (struct regcache *regcache, const void *buf)
 {
   const xtensa_regtable_t *ptr;

   for (ptr = xtensa_regmap_table; ptr->name; ptr++)
     {
       supply_register_by_name (regcache, ptr->name,
 				(char*)buf + ptr->ptrace_offset);
     }
 }

 static struct regset_info xtensa_regsets[] = {
   { PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
     GENERAL_REGS,
     xtensa_fill_gregset, xtensa_store_gregset },
   { PTRACE_GETXTREGS, PTRACE_SETXTREGS, 0, XTENSA_ELF_XTREG_SIZE,
     EXTENDED_REGS,
     xtensa_fill_xtregset, xtensa_store_xtregset },
   NULL_REGSET
 };

 #if XCHAL_HAVE_BE
 #define XTENSA_BREAKPOINT {0xd2,0x0f}
 #else
 #define XTENSA_BREAKPOINT {0x2d,0xf0}
 #endif

 static const gdb_byte xtensa_breakpoint[] = XTENSA_BREAKPOINT;
 #define xtensa_breakpoint_len 2

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

 const gdb_byte *
 xtensa_target::sw_breakpoint_from_kind (int kind, int *size)
 {
   *size = xtensa_breakpoint_len;
   return xtensa_breakpoint;
 }

 bool
 xtensa_target::low_breakpoint_at (CORE_ADDR where)
 {
     unsigned long insn;

     read_memory (where, (unsigned char *) &insn, xtensa_breakpoint_len);
     return memcmp((char *) &insn,
 		  xtensa_breakpoint, xtensa_breakpoint_len) == 0;
 }

 /* Called by libthread_db.  */

 ps_err_e
 ps_get_thread_area (struct ps_prochandle *ph,
 		    lwpid_t lwpid, int idx, void **base)
 {
   xtensa_elf_gregset_t regs;

   if (ptrace (PTRACE_GETREGS, lwpid, NULL, &regs) != 0)
     return PS_ERR;

   /* IDX is the bias from the thread pointer to the beginning of the
      thread descriptor.  It has to be subtracted due to implementation
      quirks in libthread_db.  */
   *base = (void *) ((char *) regs.threadptr - idx);

   return PS_OK;
 }

 static struct regsets_info xtensa_regsets_info =
   {
     xtensa_regsets, /* regsets */
     0, /* num_regsets */
     NULL, /* disabled_regsets */
   };

 static struct regs_info myregs_info =
   {
     NULL, /* regset_bitmap */
     NULL, /* usrregs */
     &xtensa_regsets_info
   };

 void
 xtensa_target::low_arch_setup ()
 {
   current_process ()->tdesc = tdesc_xtensa;
 }

 const regs_info *
 xtensa_target::get_regs_info ()
 {
   return &myregs_info;
 }

 /* The linux target ops object.  */

 linux_process_target *the_linux_target = &the_xtensa_target;

 void
 initialize_low_arch (void)
 {
   /* Initialize the Linux target descriptions.  */
   init_registers_xtensa ();

   initialize_regsets_info (&xtensa_regsets_info);
 }
	/* GNU/Linux/Xtensa specific low level interface, for the remote server for GDB.
	Copyright (C) 2007-2021 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 "server.h"
	#include "linux-low.h"

	/* Linux target op definitions for the Xtensa architecture. */

	class xtensa_target : public linux_process_target
	{
	public:

	const regs_info *get_regs_info () 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_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 xtensa_target the_xtensa_target;

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

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

	CORE_ADDR
	xtensa_target::low_get_pc (regcache *regcache)
	{
	return linux_get_pc_32bit (regcache);
	}

	void
	xtensa_target::low_set_pc (regcache *regcache, CORE_ADDR pc)
	{
	linux_set_pc_32bit (regcache, pc);
	}

	/* Defined in auto-generated file reg-xtensa.c. */
	void init_registers_xtensa (void);
	extern const struct target_desc *tdesc_xtensa;

	#include <asm/ptrace.h>
	#include <xtensa-config.h>
	#include "arch/xtensa.h"
	#include "gdb_proc_service.h"

	#include "xtensa-xtregs.c"

	enum regnum {
	R_PC=0, R_PS,
	R_LBEG, R_LEND, R_LCOUNT,
	R_SAR,
	R_WS, R_WB,
	R_THREADPTR,
	R_A0 = 64
	};

	static void
	xtensa_fill_gregset (struct regcache regcache, void buf)
	{
	elf_greg_t* rset = (elf_greg_t*)buf;
	const struct target_desc *tdesc = regcache->tdesc;
	int ar0_regnum;
	char *ptr;
	int i;

	/* Take care of AR registers. */

	ar0_regnum = find_regno (tdesc, "ar0");
	ptr = (char*)&rset[R_A0];

	for (i = ar0_regnum; i < ar0_regnum + XCHAL_NUM_AREGS; i++)
	{
	collect_register (regcache, i, ptr);
	ptr += register_size (tdesc, i);
	}

	if (XSHAL_ABI == XTHAL_ABI_CALL0)
	{
	int a0_regnum = find_regno (tdesc, "a0");
	ptr = (char ) &rset[R_A0 + 4 rset[R_WB]];

	for (i = a0_regnum; i < a0_regnum + C0_NREGS; i++)
	{
	if ((4 * rset[R_WB] + i - a0_regnum) == XCHAL_NUM_AREGS)
	ptr = (char *) &rset[R_A0];
	collect_register (regcache, i, ptr);
	ptr += register_size (tdesc, i);
	}
	}

	/* Loop registers, if hardware has it. */

	#if XCHAL_HAVE_LOOPS
	collect_register_by_name (regcache, "lbeg", (char*)&rset[R_LBEG]);
	collect_register_by_name (regcache, "lend", (char*)&rset[R_LEND]);
	collect_register_by_name (regcache, "lcount", (char*)&rset[R_LCOUNT]);
	#endif

	collect_register_by_name (regcache, "sar", (char*)&rset[R_SAR]);
	collect_register_by_name (regcache, "pc", (char*)&rset[R_PC]);
	collect_register_by_name (regcache, "ps", (char*)&rset[R_PS]);
	collect_register_by_name (regcache, "windowbase", (char*)&rset[R_WB]);
	collect_register_by_name (regcache, "windowstart", (char*)&rset[R_WS]);

	#if XCHAL_HAVE_THREADPTR
	collect_register_by_name (regcache, "threadptr",
	(char *) &rset[R_THREADPTR]);
	#endif
	}

	static void
	xtensa_store_gregset (struct regcache regcache, const void buf)
	{
	const elf_greg_t* rset = (const elf_greg_t*)buf;
	const struct target_desc *tdesc = regcache->tdesc;
	int ar0_regnum;
	char *ptr;
	int i;

	/* Take care of AR registers. */

	ar0_regnum = find_regno (tdesc, "ar0");
	ptr = (char *)&rset[R_A0];

	for (i = ar0_regnum; i < ar0_regnum + XCHAL_NUM_AREGS; i++)
	{
	supply_register (regcache, i, ptr);
	ptr += register_size (tdesc, i);
	}

	if (XSHAL_ABI == XTHAL_ABI_CALL0)
	{
	int a0_regnum = find_regno (tdesc, "a0");
	ptr = (char ) &rset[R_A0 + (4 rset[R_WB]) % XCHAL_NUM_AREGS];

	for (i = a0_regnum; i < a0_regnum + C0_NREGS; i++)
	{
	if ((4 * rset[R_WB] + i - a0_regnum) == XCHAL_NUM_AREGS)
	ptr = (char *) &rset[R_A0];
	supply_register (regcache, i, ptr);
	ptr += register_size (tdesc, i);
	}
	}

	/* Loop registers, if hardware has it. */

	#if XCHAL_HAVE_LOOPS
	supply_register_by_name (regcache, "lbeg", (char*)&rset[R_LBEG]);
	supply_register_by_name (regcache, "lend", (char*)&rset[R_LEND]);
	supply_register_by_name (regcache, "lcount", (char*)&rset[R_LCOUNT]);
	#endif

	supply_register_by_name (regcache, "sar", (char*)&rset[R_SAR]);
	supply_register_by_name (regcache, "pc", (char*)&rset[R_PC]);
	supply_register_by_name (regcache, "ps", (char*)&rset[R_PS]);
	supply_register_by_name (regcache, "windowbase", (char*)&rset[R_WB]);
	supply_register_by_name (regcache, "windowstart", (char*)&rset[R_WS]);

	#if XCHAL_HAVE_THREADPTR
	supply_register_by_name (regcache, "threadptr",
	(char *) &rset[R_THREADPTR]);
	#endif
	}

	/* Xtensa GNU/Linux PTRACE interface includes extended register set. */

	static void
	xtensa_fill_xtregset (struct regcache regcache, void buf)
	{
	const xtensa_regtable_t *ptr;

	for (ptr = xtensa_regmap_table; ptr->name; ptr++)
	{
	collect_register_by_name (regcache, ptr->name,
	(char*)buf + ptr->ptrace_offset);
	}
	}

	static void
	xtensa_store_xtregset (struct regcache regcache, const void buf)
	{
	const xtensa_regtable_t *ptr;

	for (ptr = xtensa_regmap_table; ptr->name; ptr++)
	{
	supply_register_by_name (regcache, ptr->name,
	(char*)buf + ptr->ptrace_offset);
	}
	}

	static struct regset_info xtensa_regsets[] = {
	{ PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
	GENERAL_REGS,
	xtensa_fill_gregset, xtensa_store_gregset },
	{ PTRACE_GETXTREGS, PTRACE_SETXTREGS, 0, XTENSA_ELF_XTREG_SIZE,
	EXTENDED_REGS,
	xtensa_fill_xtregset, xtensa_store_xtregset },
	NULL_REGSET
	};

	#if XCHAL_HAVE_BE
	#define XTENSA_BREAKPOINT {0xd2,0x0f}
	#else
	#define XTENSA_BREAKPOINT {0x2d,0xf0}
	#endif

	static const gdb_byte xtensa_breakpoint[] = XTENSA_BREAKPOINT;
	#define xtensa_breakpoint_len 2

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

	const gdb_byte *
	xtensa_target::sw_breakpoint_from_kind (int kind, int *size)
	{
	*size = xtensa_breakpoint_len;
	return xtensa_breakpoint;
	}

	bool
	xtensa_target::low_breakpoint_at (CORE_ADDR where)
	{
	unsigned long insn;

	read_memory (where, (unsigned char *) &insn, xtensa_breakpoint_len);
	return memcmp((char *) &insn,
	xtensa_breakpoint, xtensa_breakpoint_len) == 0;
	}

	/* Called by libthread_db. */

	ps_err_e
	ps_get_thread_area (struct ps_prochandle *ph,
	lwpid_t lwpid, int idx, void **base)
	{
	xtensa_elf_gregset_t regs;

	if (ptrace (PTRACE_GETREGS, lwpid, NULL, &regs) != 0)
	return PS_ERR;

	/* IDX is the bias from the thread pointer to the beginning of the
	thread descriptor. It has to be subtracted due to implementation
	quirks in libthread_db. */
	base = (void ) ((char *) regs.threadptr - idx);

	return PS_OK;
	}

	static struct regsets_info xtensa_regsets_info =
	{
	xtensa_regsets, /* regsets */
	0, /* num_regsets */
	NULL, /* disabled_regsets */
	};

	static struct regs_info myregs_info =
	{
	NULL, /* regset_bitmap */
	NULL, /* usrregs */
	&xtensa_regsets_info
	};

	void
	xtensa_target::low_arch_setup ()
	{
	current_process ()->tdesc = tdesc_xtensa;
	}

	const regs_info *
	xtensa_target::get_regs_info ()
	{
	return &myregs_info;
	}

	/* The linux target ops object. */

	linux_process_target *the_linux_target = &the_xtensa_target;

	void
	initialize_low_arch (void)
	{
	/* Initialize the Linux target descriptions. */
	init_registers_xtensa ();

	initialize_regsets_info (&xtensa_regsets_info);
	}