gdb/or1k-linux-tdep.c

   1 /* Target-dependent code for GNU/Linux on OpenRISC processors.
   2    Copyright (C) 2018-2022 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include "defs.h"
  20 #include "or1k-tdep.h"
  21 #include "osabi.h"
  22 #include "glibc-tdep.h"
  23 #include "linux-tdep.h"
  24 #include "solib-svr4.h"
  25 #include "regset.h"
  26 #include "tramp-frame.h"
  27 #include "trad-frame.h"
  28 #include "gdbarch.h"
  29
  30 #include "features/or1k-linux.c"
  31
  32 /* Define the general register mapping.  The kernel and GDB put registers
  33    r1 to r31 in the same place.  The NPC register is stored at index 32 in
  34    linux and 33 in GDB, in GDB 32 is for PPC which is not popupated from linux.
  35    Register r0 is always 0 and can be ignored.  */
  36
  37 static const struct regcache_map_entry or1k_linux_gregmap[] =
  38 {
  39   { 32, OR1K_ZERO_REGNUM, 4 }, /* r0 to r31 */
  40   { 1,  OR1K_NPC_REGNUM, 4 },
  41   { 0 }
  42 };
  43
  44 /* Define the general register regset.  */
  45
  46 static const struct regset or1k_linux_gregset =
  47 {
  48   or1k_linux_gregmap, regcache_supply_regset, regcache_collect_regset
  49 };
  50
  51 /* Define hook for core file support.  */
  52
  53 static void
  54 or1k_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
  55                                          iterate_over_regset_sections_cb *cb,
  56                                          void *cb_data,
  57                                          const struct regcache *regcache)
  58 {
  59   cb (".reg", (33 * 4), (33 * 4), &or1k_linux_gregset, NULL, cb_data);
  60 }
  61
  62 /* Signal trampoline support.  */
  63
  64 static void or1k_linux_sigframe_init (const struct tramp_frame *self,
  65                                        frame_info_ptr this_frame,
  66                                        struct trad_frame_cache *this_cache,
  67                                        CORE_ADDR func);
  68
  69 #define OR1K_RT_SIGRETURN               139
  70
  71 #define OR1K_INST_L_ORI_R11_R0_IMM      0xa9600000
  72 #define OR1K_INST_L_SYS_1               0x20000001
  73 #define OR1K_INST_L_NOP                 0x15000000
  74
  75 static const struct tramp_frame or1k_linux_sigframe = {
  76   SIGTRAMP_FRAME,
  77   4,
  78   {
  79     { OR1K_INST_L_ORI_R11_R0_IMM | OR1K_RT_SIGRETURN, ULONGEST_MAX },
  80     { OR1K_INST_L_SYS_1, ULONGEST_MAX },
  81     { OR1K_INST_L_NOP, ULONGEST_MAX },
  82     { TRAMP_SENTINEL_INSN }
  83   },
  84   or1k_linux_sigframe_init,
  85   NULL
  86 };
  87
  88 /* Runtime signal frames look like this:
  89   struct rt_sigframe {
  90     struct siginfo info;
  91     struct ucontext uc;
  92     unsigned char retcode[16];
  93   };
  94
  95   struct ucontext {
  96     unsigned long     uc_flags;     - 4
  97     struct ucontext  *uc_link;      - 4
  98     stack_t           uc_stack;     - 4 * 3
  99     struct sigcontext uc_mcontext;
 100     sigset_t          uc_sigmask;
 101   };
 102
 103   struct sigcontext {
 104     struct user_regs_struct regs;
 105     unsigned long oldmask;
 106   };
 107
 108   struct user_regs_struct {
 109     unsigned long gpr[32];
 110     unsigned long pc;
 111     unsigned long sr;
 112   };  */
 113
 114 #define SIGFRAME_SIGINFO_SIZE           128
 115 #define UCONTEXT_MCONTEXT_OFFSET        20
 116
 117 static void
 118 or1k_linux_sigframe_init (const struct tramp_frame *self,
 119                            frame_info_ptr this_frame,
 120                            struct trad_frame_cache *this_cache,
 121                            CORE_ADDR func)
 122 {
 123   CORE_ADDR frame_sp = get_frame_sp (this_frame);
 124   CORE_ADDR mcontext_base;
 125   CORE_ADDR regs_base;
 126
 127   mcontext_base = frame_sp + SIGFRAME_SIGINFO_SIZE + UCONTEXT_MCONTEXT_OFFSET;
 128
 129   /* Handle the general registers 0-31 followed by the PC.  */
 130   regs_base = mcontext_base;
 131   for (int i = 0; i < 32; i++)
 132     trad_frame_set_reg_addr (this_cache, OR1K_ZERO_REGNUM + i,
 133                              regs_base + (i * 4));
 134   trad_frame_set_reg_addr (this_cache, OR1K_NPC_REGNUM, regs_base + (32 * 4));
 135   trad_frame_set_reg_addr (this_cache, OR1K_SR_REGNUM, regs_base + (33 * 4));
 136
 137   /* Choice of the bottom of the sigframe is somewhat arbitrary.  */
 138   trad_frame_set_id (this_cache, frame_id_build (frame_sp, func));
 139 }
 140
 141 /* Initialize OpenRISC Linux ABI info.  */
 142
 143 static void
 144 or1k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 145 {
 146   linux_init_abi (info, gdbarch, 0);
 147
 148   set_solib_svr4_fetch_link_map_offsets (gdbarch,
 149                                          linux_ilp32_fetch_link_map_offsets);
 150
 151   /* GNU/Linux uses SVR4-style shared libraries.  */
 152   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 153
 154   /* GNU/Linux uses the dynamic linker included in the GNU C Library.  */
 155   set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
 156
 157   set_gdbarch_software_single_step (gdbarch, or1k_software_single_step);
 158
 159   /* Enable TLS support.  */
 160   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 161                                              svr4_fetch_objfile_link_map);
 162
 163   set_gdbarch_iterate_over_regset_sections
 164     (gdbarch, or1k_linux_iterate_over_regset_sections);
 165
 166   tramp_frame_prepend_unwinder (gdbarch, &or1k_linux_sigframe);
 167 }
 168
 169 /* Initialize OpenRISC Linux target support.  */
 170
 171 void _initialize_or1k_linux_tdep ();
 172 void
 173 _initialize_or1k_linux_tdep ()
 174 {
 175   gdbarch_register_osabi (bfd_arch_or1k, 0, GDB_OSABI_LINUX,
 176                           or1k_linux_init_abi);
 177
 178   /* Initialize the standard target descriptions.  */
 179   initialize_tdesc_or1k_linux ();
 180 }