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+/* GNU/Linux/Xtensa specific low level interface, for the remote server for GDB.
+ Copyright (C) 2007-2020 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"
+
+/* 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 linux_target_ops method "sw_breakpoint_from_kind". */
+
+static const gdb_byte *
+xtensa_sw_breakpoint_from_kind (int kind, int *size)
+{
+ *size = xtensa_breakpoint_len;
+ return xtensa_breakpoint;
+}
+
+static int
+xtensa_breakpoint_at (CORE_ADDR where)
+{
+ unsigned long insn;
+
+ (*the_target->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 regs_info =
+ {
+ NULL, /* regset_bitmap */
+ NULL, /* usrregs */
+ &xtensa_regsets_info
+ };
+
+static void
+xtensa_arch_setup (void)
+{
+ current_process ()->tdesc = tdesc_xtensa;
+}
+
+/* Support for hardware single step. */
+
+static int
+xtensa_supports_hardware_single_step (void)
+{
+ return 1;
+}
+
+static const struct regs_info *
+xtensa_regs_info (void)
+{
+ return &regs_info;
+}
+
+struct linux_target_ops the_low_target = {
+ xtensa_arch_setup,
+ xtensa_regs_info,
+ 0,
+ 0,
+ NULL, /* fetch_register */
+ linux_get_pc_32bit,
+ linux_set_pc_32bit,
+ NULL, /* breakpoint_kind_from_pc */
+ xtensa_sw_breakpoint_from_kind,
+ NULL,
+ 0,
+ xtensa_breakpoint_at,
+ NULL, /* supports_z_point_type */
+ NULL, /* insert_point */
+ NULL, /* remove_point */
+ NULL, /* stopped_by_watchpoint */
+ NULL, /* stopped_data_address */
+ NULL, /* collect_ptrace_register */
+ NULL, /* supply_ptrace_register */
+ NULL, /* siginfo_fixup */
+ NULL, /* new_process */
+ NULL, /* delete_process */
+ NULL, /* new_thread */
+ NULL, /* delete_thread */
+ NULL, /* new_fork */
+ NULL, /* prepare_to_resume */
+ NULL, /* process_qsupported */
+ NULL, /* supports_tracepoints */
+ NULL, /* get_thread_area */
+ NULL, /* install_fast_tracepoint_jump_pad */
+ NULL, /* emit_ops */
+ NULL, /* get_min_fast_tracepoint_insn_len */
+ NULL, /* supports_range_stepping */
+ NULL, /* breakpoint_kind_from_current_state */
+ xtensa_supports_hardware_single_step,
+};
+
+
+void
+initialize_low_arch (void)
+{
+ /* Initialize the Linux target descriptions. */
+ init_registers_xtensa ();
+
+ initialize_regsets_info (&xtensa_regsets_info);
+}