gdb/or1k-linux-tdep.c

   1 /* Target-dependent code for GNU/Linux on OpenRISC processors.
   2    Copyright (C) 2018-2024 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 "or1k-tdep.h"
  20 #include "osabi.h"
  21 #include "glibc-tdep.h"
  22 #include "linux-tdep.h"
  23 #include "solib-svr4.h"
  24 #include "regset.h"
  25 #include "tramp-frame.h"
  26 #include "trad-frame.h"
  27 #include "gdbarch.h"
  28
  29 #include "features/or1k-linux.c"
  30
  31 /* Define the general register mapping.  The kernel and GDB put registers
  32    r1 to r31 in the same place.  The NPC register is stored at index 32 in
  33    linux and 33 in GDB, in GDB 32 is for PPC which is not populated from linux.
  34    Register r0 is always 0 and can be ignored.  */
  35
  36 static const struct regcache_map_entry or1k_linux_gregmap[] =
  37 {
  38   { 32, OR1K_ZERO_REGNUM, 4 }, /* r0 to r31 */
  39   { 1,  OR1K_NPC_REGNUM, 4 },
  40   { 0 }
  41 };
  42
  43 /* Define the general register regset.  */
  44
  45 static const struct regset or1k_linux_gregset =
  46 {
  47   or1k_linux_gregmap, regcache_supply_regset, regcache_collect_regset
  48 };
  49
  50 /* Define hook for core file support.  */
  51
  52 static void
  53 or1k_linux_iterate_over_regset_sections (struct gdbarch *gdbarch,
  54                                          iterate_over_regset_sections_cb *cb,
  55                                          void *cb_data,
  56                                          const struct regcache *regcache)
  57 {
  58   cb (".reg", (33 * 4), (33 * 4), &or1k_linux_gregset, NULL, cb_data);
  59 }
  60
  61 /* Signal trampoline support.  */
  62
  63 static void or1k_linux_sigframe_init (const struct tramp_frame *self,
  64                                        const frame_info_ptr &this_frame,
  65                                        struct trad_frame_cache *this_cache,
  66                                        CORE_ADDR func);
  67
  68 #define OR1K_RT_SIGRETURN               139
  69
  70 #define OR1K_INST_L_ORI_R11_R0_IMM      0xa9600000
  71 #define OR1K_INST_L_SYS_1               0x20000001
  72 #define OR1K_INST_L_NOP                 0x15000000
  73
  74 static const struct tramp_frame or1k_linux_sigframe = {
  75   SIGTRAMP_FRAME,
  76   4,
  77   {
  78     { OR1K_INST_L_ORI_R11_R0_IMM | OR1K_RT_SIGRETURN, ULONGEST_MAX },
  79     { OR1K_INST_L_SYS_1, ULONGEST_MAX },
  80     { OR1K_INST_L_NOP, ULONGEST_MAX },
  81     { TRAMP_SENTINEL_INSN }
  82   },
  83   or1k_linux_sigframe_init,
  84   NULL
  85 };
  86
  87 /* Runtime signal frames look like this:
  88   struct rt_sigframe {
  89     struct siginfo info;
  90     struct ucontext uc;
  91     unsigned char retcode[16];
  92   };
  93
  94   struct ucontext {
  95     unsigned long     uc_flags;     - 4
  96     struct ucontext  *uc_link;      - 4
  97     stack_t           uc_stack;     - 4 * 3
  98     struct sigcontext uc_mcontext;
  99     sigset_t          uc_sigmask;
 100   };
 101
 102   struct sigcontext {
 103     struct user_regs_struct regs;
 104     unsigned long oldmask;
 105   };
 106
 107   struct user_regs_struct {
 108     unsigned long gpr[32];
 109     unsigned long pc;
 110     unsigned long sr;
 111   };  */
 112
 113 #define SIGFRAME_SIGINFO_SIZE           128
 114 #define UCONTEXT_MCONTEXT_OFFSET        20
 115
 116 static void
 117 or1k_linux_sigframe_init (const struct tramp_frame *self,
 118                            const frame_info_ptr &this_frame,
 119                            struct trad_frame_cache *this_cache,
 120                            CORE_ADDR func)
 121 {
 122   CORE_ADDR frame_sp = get_frame_sp (this_frame);
 123   CORE_ADDR mcontext_base;
 124   CORE_ADDR regs_base;
 125
 126   mcontext_base = frame_sp + SIGFRAME_SIGINFO_SIZE + UCONTEXT_MCONTEXT_OFFSET;
 127
 128   /* Handle the general registers 0-31 followed by the PC.  */
 129   regs_base = mcontext_base;
 130   for (int i = 0; i < 32; i++)
 131     trad_frame_set_reg_addr (this_cache, OR1K_ZERO_REGNUM + i,
 132                              regs_base + (i * 4));
 133   trad_frame_set_reg_addr (this_cache, OR1K_NPC_REGNUM, regs_base + (32 * 4));
 134   trad_frame_set_reg_addr (this_cache, OR1K_SR_REGNUM, regs_base + (33 * 4));
 135
 136   /* Choice of the bottom of the sigframe is somewhat arbitrary.  */
 137   trad_frame_set_id (this_cache, frame_id_build (frame_sp, func));
 138 }
 139
 140 /* Initialize OpenRISC Linux ABI info.  */
 141
 142 static void
 143 or1k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 144 {
 145   linux_init_abi (info, gdbarch, 0);
 146
 147   set_solib_svr4_fetch_link_map_offsets (gdbarch,
 148                                          linux_ilp32_fetch_link_map_offsets);
 149
 150   /* GNU/Linux uses SVR4-style shared libraries.  */
 151   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 152
 153   /* GNU/Linux uses the dynamic linker included in the GNU C Library.  */
 154   set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver);
 155
 156   set_gdbarch_software_single_step (gdbarch, or1k_software_single_step);
 157
 158   /* Enable TLS support.  */
 159   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 160                                              svr4_fetch_objfile_link_map);
 161
 162   set_gdbarch_iterate_over_regset_sections
 163     (gdbarch, or1k_linux_iterate_over_regset_sections);
 164
 165   tramp_frame_prepend_unwinder (gdbarch, &or1k_linux_sigframe);
 166 }
 167
 168 /* Initialize OpenRISC Linux target support.  */
 169
 170 void _initialize_or1k_linux_tdep ();
 171 void
 172 _initialize_or1k_linux_tdep ()
 173 {
 174   gdbarch_register_osabi (bfd_arch_or1k, 0, GDB_OSABI_LINUX,
 175                           or1k_linux_init_abi);
 176
 177   /* Initialize the standard target descriptions.  */
 178   initialize_tdesc_or1k_linux ();
 179 }